Legacy Experimental Release Notes

This page is to list the deprecated experimental release notes. Stable release notes can be viewed here.

Experimental Releases (deprecated)

Experimental Releases

Update: As of November 2022, a separate experimental builds package has no longer been needed. Experimental features are now distributed within the stable and demo versions of the addon and are disabled/hidden by default under the FLIP Fluids Preferences > Enable Developer Tools option.

Experimental releases will give you access to the latest updates and features, but these builds may contain bugs and lack documentation. Please let us know what you think of the experimental builds or notice any problems, we love to hear your feedback!

Experimental Versions 9.6.x

Release notes for experimental version 9.6.x, which correspond to the stable FLIP Fluids Version 1.6.0. These versions contain the latest features, fixes, and improvements. Please read our Experimental Builds documentation before testing these versions.

version 9.6.1 (Nov 24 2022)

This experimental release corresponds with the stable 1.6.0 release and contains minimal changes. Refer to the 1.6.0 release notes.

Experimental Versions 9.5.x

Release notes for experimental version 9.5.x, which correspond to the stable FLIP Fluids Version 1.5.0. These versions contain the latest features, fixes, and improvements. Please read our Experimental Builds documentation before testing these versions.

version 9.5.1 (Sep 07 2022)

This experimental release corresponds with the stable 1.5.0 release and contains minimal changes. Refer to the 1.5.0 release notes.

Experimental Versions 9.4.x

Release notes for experimental version 9.4.x, which correspond to the stable FLIP Fluids Version 1.4.0. These versions contain the latest features, fixes, and improvements. Please read our Experimental Builds documentation before testing these versions.

version 9.4.3 (Aug 05 2022)

This version mainly adds a new physically-based color mixing mode.
Blender 3.3 and 3.4 Compatibility: At this moment there are no known compatibility issues between this version of the FLIP Fluids addon and Blender 3.3 and 3.4.
Added: New "Mixbox" color mixing mode for the fluid surface attributes.
- Mixbox is a tool developed by Secret Weapons for simulating physically-based pigment mixing. Learn more about the Mixbox technology here: Secret Weapons - Mixbox.
- The Mixbox features are installed and activated through a plugin. Installation instructions:
  1. Download the plugin - The plugin file can be found in the Experimental Builds Package and is labeled as Mixbox.plugin.
  2. Open addon preferences - Open the FLIP Fluids addon preferences menu (Help > FLIP Fluids > FLIP Fluids Preferences).
  3. Install the plugin - Navigate to the Preferences > Mixbox Color Blending Plugin submenu. Click the Install Mixbox Plugin operator, select the Mixbox.plugin file, and click Install Mixbox.
- After installation you may delete or archive the Mixbox.plugin file.
- The Mixbox color mixing mode can be set in the Domain > FLIP Fluid Surface > Geometry Attributes menu.
UI: Fixed command line operator tooltips to remove note on Windows OS exclusivity.

version 9.4.2 (Jul 07 2022)

This experimental release adds bug fixes and mainly improves support for attributes and command line tools.
Added: Expanded support for fluid surface attributes.
- Option to generate accurate velocity-based surface attributes against obstacles. Notes:
  - Velocity-based attributes are the velocity, speed, and vorticity attributes of the fluid surface.
  - If this option is enabled, correct velocity-based attributes will be generated at the interface where the liquid and obstacles meet, but at the cost of simulation performance.
  - If disabled, velocity-based attributes where liquid and obstacles meet may be incorrect and may contain motion blur spikes or shading artifacts.
  - This option only needs to be enabled if rendering with velocity-based shaders and/or motion blur where the liquid-obstacle interface is visible, such as when there are transparent/invisible obstacles.
- Attributes are now supported when using the Upscale Domain Resolution on Resume feature. Previously, attributes would be initialized to a default values on resume when using this feature.
- Attributes are now supported when using the Sheeting Effects feature. Previously, newly created fluid particle attributes would be initialized to a default value.
- Attributes are now supported when the FLIP Fluid Surface > Particle Scale is greater or less than the default value of 1.0. Previously, using larger or smaller values could result in shading artifacts or missing attribute data.
- Exceptions: The Source ID attribute will not be supported in the above changes. This attribute is deprecated and is being replaced by a similar attribute that expands functionality and improves use cases.
Added: Expanded command line operator support to MacOS and Linux (previously Windows-only features). Notes:
- Operators that automatically launch a new command line window processes are now supported on MacOS and Linux.
- These operators include the Bake Simulation, Render Animation, and Render Frame features.
- These operators can be found in the FLIP Fluids Sidebar > Command Line Tools menu.
- Linux notes:
  - These features rely on and assume that the xterm terminal emulator is available on the PATH in your Linux distribution.
  - If the option to open image file after rendering a frame is enabled, the xdg-open program will be used to open the file.
Added: Shortcut operator to the Blender > Help > FLIP Fluids submenu that opens the FLIP Fluids addon preferences.
Added: Functionality to preserve Color Attribute mesh data groups between frames in Blender 3.2. Note: the Color Attribute group functions similarly to the deprecated Vertex Color group in Blender 3.1 and earlier.
Bug Fix: Fixed error that could be triggered if a simulation mesh contained a Vertex Color group in a .blend file created in Blender 3.1 or earlier that was opened in Blender 3.2 or later.
Bug Fix: Fixed UI issue where cache info stats could display a vorticity attribute entry when the vorticity attribute was not enabled.
Bug Fix: Fixed error that could be triggered if a surface/whitewater mesh object was in edit mode while starting/resetting a bake.
Bug Fix: Fixed issue where resuming from an earlier savestate and ending the simulation before the frame completes may not update the most recent savestate to the correct frame.
Bug Fix: Fixed misc errors that could be triggered in the OTOY Octane Render for Blender 3.1 version when the renderer was set to Octane.
Change: Reduced log filename length to a max character length to prevent filepaths from becoming to long in order to reduce Windows OS path length related issues.
Improvement: improved accuracy and performance of color attribute to mesh transfer.
UI: Initialize Motion Blur operator in the sidebar now cannot be used without first enabling the Preferences > Developer Tools option. This sidebar menu will now prompt the user to enable the developer tools option. This change will only affect future stable versions as the developer tools option is not relevant in experimental versions.
UI: removed redundant Render Tools menu from sidebar.

version 9.4.1 (Jun 07 2022)

This experimental release corresponds with the stable 1.4.0 release and contains minimal changes. Refer to the 1.4.0 release notes.

Experimental Versions 9.3.x

Release notes for experimental version 9.3.x, which correspond to the stable FLIP Fluids Version 1.3.0. These versions contain the latest features, fixes, and improvements. Please read our Experimental Builds documentation before testing these versions.

version 9.3.4 (Jun 01 2022)

This experimental version is a release candidate for the next stable FLIP Fluids version 1.4.0 to be released shortly before the release of Blender 3.2 (June 8th 2022).
Blender 3.2 and 3.3 Compatibility: At this moment there are no known compatibility issues between this version of the FLIP Fluids addon and Blender 3.2 and 3.3.
Added: Render After Bake option to the Helper > Command Line Tools sidebar to automatically start a command line animation render after the command line bake process is completed.
- This option offers a selection between a normal command line render or to launch a frame by frame batch file render.
- Automatically launching the command line process is supported on Windows only. For MacOS/Linux, the Copy Bake Command operator can be used to copy the command to the clipboard so that it can be manually pasted in a terminal window.
Added: Launch Frame Render option to the Helper > Command Line Tools sidebar to automatically launch a command line render for a single frame.
- This operator will render the current timeline frame.
- If the Open Image After Render option is enabled, the command line script will automatically open the image using the default image program of your OS after the render is completed.
- If the Close CMD Window After Render option is enabled, the command line window will be automatically closed after the render is completed.
- The .blend file should be saved before using this operator in order for render and simulation settings to take effect. However, it is not required to save the .blend file if you are only changing a frame in the timeline or if changing the two above settings.
- This operator is supported on Windows only. For MacOS/Linux, the Copy Render Command operator can be used to copy the command to the clipboard so that it can be manually pasted in a terminal window. The above two options are not supported on MacOS/Linux.
Added: Age and Color surface attribute blending options to the FLIP Fluid Surface > Geometry Attributes menu.
- These options control the amount of smoothing when blending the Age or Color attributes during simulation. Higher values result in smoother attribute transitions at the cost of simulation performance. The blending value represents the blending radius in number of voxels.
Bug Fix: Fixed issue where generated surface attribute data could be incorrect on the under-side of the surface mesh, or in the direction that the liquid was flowing.
Change: The generated batch file render window will no longer close after completing the render.
Change: The Helper > Initialize Motion Blur sidebar operator will now generate a separate geometry node group for each whitewater particle type (foam/bubble/spray/dust) instead of a single group.
- Note: if using this operator on a simulation set up where you had used this operator previously, you may want to check for duplicate geometry node groups in the modifiers panel and delete the old one.
Change: The FLIP Fluid World > Viscosity Accuracy now has a soft maximum value of 4. The value can still be manually set up to a maximum of 6, but we would in general not recommend setting this value above 4 in any case as there are greatly diminishing returns in visual accuracy.
Improvement: Age and Color attribute generation is now optimized and multithreaded.

version 9.3.3 (May 25 2022)

Blender 3.2 and 3.3 Compatibility: At this moment there are no known compatibility issues between this version of the FLIP Fluids addon and Blender 3.2 and 3.3.
Added: Functionality to the Surface Force Field object for selectively generating force vector fields based on front/backfacing triangle direction as well as against planar edges (Documentation). Notes:
- Enabled Sides: Front - Enable force field on the front-facing polygons. This is the side where face normals point outwards.
- Enabled Sides: Back - Enable force field on the back-facing polygons. This is the side opposite of the face normal.
- Enabled Sides: Edge - Enable force field on planar edges. These are the edges of the surface that are not connected to any other polygons. Must have either one of Back or Front sides enabled for edge attraction to be enabled. Tip: Disable this option if you want the fluid to be attracted to the surface while still being able to flow off the edges of the surface.
Bug Fix: Added optimizations to prevent the addon from slowing down the Blender UI when the addon is not in use (issue #582).
Bug Fix: Fixed issue where surface/whitewater motion blur could be rendered incorrectly on the first frame of an animation.
Bug Fix: Fixed possible AttributeError that could be triggered when deleting an object when a domain is present in the scene.
Bug Fix: Fixed issues where cache paths saved on Windows may not load on macOS/Linux due to backslashes in filepath.
Bug Fix: Fixed error that could be triggered when using the Create Domain operator when a thin object is selected.
Bug Fix: Fixed issue where Create Domain operator could automatically adjust resolution too high for force fields that are allowed to be planar surface or points.
Bug Fix: Fixed issue where resuming a simulation could resume with incorrect Source ID attribute values on the fluid surface.
UI: The Select Domain operator will now still be accessible when the Helper > Select Objects panel is collapsed.
UI: Added a Restart Required warning to the FLIP Fluids sidebar menu to prevent user from setting up a simulation and triggering errors before installation is complete.
UI: Expanded Obstacle > Inverse option tooltip to improve on explaining what this option does (Documentation).

version 9.3.2 (Mar 30 2022)

This experimental release corresponds with the stable 1.3.1 release and contains minimal changes. Refer to the 1.3.1 release notes.

version 9.3.1 (Mar 11 2022)

This experimental release corresponds with the stable 1.3.0 release and contains minimal changes. Refer to the 1.3.0 release notes.

Experimental Versions 9.2.x

Release notes for experimental version 9.2.x, which correspond to the stable FLIP Fluids Version 1.2.0. These versions contain the latest features, fixes, and improvements. Please read our Experimental Builds documentation before testing these versions.

version 9.2.2 (Feb 11 2022)

This is the first experimental build since FLIP Fluids Stable 1.2.1 and mainly adds attribute functionality for whitewater particles.
- An installation of Blender 3.1 dated February 3rd 2022 or later is required to use these features.
- If using both stable and experimental versions, we recommend creating separate saves for .blend files between these versions.
- We recommend saving very frequently when working with attributes. There may be bugs that can cause crashes during attribute set up that we will need to report to the developers.
- Due to a bug that can cause frequent render crashes when using attributes (T88811), rendering from the command line will be necessary when using attribute features.
Added: Whitewater attributes using Blender 3.1's new pointcloud object type. These options can be found in the FLIP Fluid Whitewater panel.
- Added functionality to export a 3D velocity vector attribute for whitewater particles as flip_velocity.
- Added functionality to export an integer stable ID attribute for whitewater particles as flip_id.
- Added functionality to export a float lifetime attribute for whitewater particles as flip_lifetime.
- Added example files to experimental builds package to demonstrate how to use these features.
  - 0_whitewater-basic_pointcloud.blend - How to convert whitewater to a pointcloud object type.
  - 1_surface_and_whitewater-basic_motion_blur.blend - How to set up basic motion blur on both the fluid surface and whitewater particles.
  - 2_whitewater-velocity_attribute_shader.blend - How to shade whitewater particles based on velocity.
  - 3_whitewater-id_attribute_random_particle_size.blend - How to use the stable ID attribute to randomize whitewater particle size and color.
  - 4_whitewater-lifetime_attribute_based_particle_size.blend - How to use the lifetime attribute to scale down whitewater particles before they are despawned.
Added: Functionality to export a vorticity attribute for the fluid surface.
- The attribute is a 3D vector type and can be accessed with the name flip_vorticity
- Vorticity is a measure of local speed at which the liquid is rotating.
Added: Operator to FLIP Fluids Helper menu to automatically set up motion blur rendering. This operator can be found in the sidebar under the Geometry Nodes Tools submenu.
- This operator will set up everything needed for motion blur rendering and will check that the render engine is set to Cycles, that Cycles motion blur rendering is enabled, that necessary FLIP Fluids attributes are enabled, will initialize basic geometry node set ups on the fluid surface and whitewater (if enabled), and will check that the simulation mesh objects have motion blur rendering enabled.
- The operator will also display what changes were made to the .blend file in the Blender System Console window.
- This operator is best used before baking a simulation, as the attribute data may need to be baked.
Added: Functionality for the user to rename the addon folder from the default flip_fluids_addon name in the Blender addons directory.
- For advanced installation only. Can result in errors or incorrect behavior if misused.
- To enable this functionality, the user must enable the Allow Addon Directory Renaming option in the FLIP Fluids Preferences menu.
- Directory name must not include special characters, including periods ('.').
- Can be used to install multiple versions of the FLIP Fluids addon alongside each other.
  - It is very important that only one version of the addon is ever enabled at any time, or errors and incorrect behavior can result.
  - To switch between versions, first disable the current version, enable the desired version, and either restart Blender or reload the .blend file.
Bug Fix: File permission errors will now be displayed in a a popup message with user friendly information.
Bug Fix: Added error popup that prevents user from setting more than one object as a Domain. Note: the user may still be able to add multiple domains if copying/pasting a domain object, but will presented with a popup error upon attempting to bake the simulation.
Bug Fix: Fixed issue where simulation meshes would not update on a frame change if a custom whitewater instance object was set to no object.
Bug Fix: Possible workaround to Blender issue where copying geometry nodes modifiers can result in a crash.
Changes: The FLIP Fluids Preferences > Enable Developer Tools option is now always enabled in experimental builds, regardless of whether this option is set. This means that experimental features will now always be unhidden in experimental versions.
Documentation: Added Official Marketplaces of the FLIP Fluids addon page including marketplaces FAQ.
- The FLIP Fluids addon is now available on the Blender Market, Gumroad, and FlippedNormals.

version 9.2.1 (Nov 25 2021)

This experimental release corresponds with the stable 1.2.0 release and contains minimal changes. Refer to the 1.2.0 release notes.

Experimental Versions 9.1.x

Release notes for experimental version 9.1.x, which correspond to the stable FLIP Fluids Version 1.1.0. These versions contain the latest features, fixes, and improvements. Please read our Experimental Builds documentation before testing these versions.

version 9.1.4 (Nov 17 2021)

This will likely be the last experimental version before the release of the next stable version, FLIP Fluids v1.2.0 to be released on 25-nov-2021.
- At this point, it is unlikely that any changes in Blender 3.0 developments should break compatibility before the release on 03-dec-2021.
- At the moment, there are no known issues between this version of the FLIP Fluids addon and Blender 3.0.
- Issues related to Blender 3.0 compatibility can be reported and tracked in this thread: issue #535.
- Experimental versions after the next stable release will continue in the 9.2.x series.
Added: Functionality to preserve any UV Map Layers or Vertex Color Layers on the fluid mesh data (issue #561).
- Note: as the fluid meshes have dynamic topology, the values in the layers will not be transferred to the next frame. The layers will contain default data and should only be used procedurally.
Added: Alternate surface tension solving method:
- Regular: Choose for general purpose surface tension effects. This option is the default and is the same method used in previous versions.
- Smooth: Choose for improved stability, smoother results, and improved cohesion in small-scale effects. Good for thin streams/strands of liquid and for high surface tension effects. Not recommended for highly chaotic fluid motion or large volumes of liquid as this can result in volume increase issues.
Bug Fix: Issue where Re-launch Bake After Crash command line bake feature could resume the simulation from an incorrect frame after an error is encountered.
Bug Fix: Re-launch Bake After Crash command line bake feature will no longer attempt to re-launch a simulation if a Out of device/disk space error is encountered.
Bug Fix: Issue where custom drawing of text in the grid visualization feature could display with inconsistent colors depending on Blender version.
Bug Fix: Issue where building from source could display a cmake_minimum_required() deprecation warning.
Bug Fix: Issue where the option to enable surface tension could be greyed out and not selectable.
UI: Various reported typos and formatting in property tooltips (Thanks for the reports!).
UI: Tooltips and documentation have been updated to use the term Voxel rather than Grid Cell for consistency.

version 9.1.3 (Nov 03 2021)

This is a minor update that mainly updates compatibility for Blender 3.0 Beta.
Blender 3.0 Compatibility: This build is intended to be used with Blender 3.0 Beta builds dated November 3, 2021 or later.
Added: Forward compatibility support for Blender 3.0
- If a .blend file is saved in Blender 3.0 and then opened in an earlier version of Blender 2.8x or 2.9x, the addon will automatically update the .blend file so that FLIP Fluid objects are compatible and function correctly.
- We still recommend keeping Blender 3.0 .blend files and earlier versions in separate saves. Blender will warn that you may still experience data loss in the .blend file in areas/features outside of the FLIP Fluids addon.
Bug Fix: Issues related to automatically setting Cycles ray visibility for FLIP Fluid/Inflow/Outflow/Force/Domain objects in recent builds of Blender 3.0.
Bug Fix: Baking crash (Index Out Of Range or EXCEPTION_ACCESS_VIOLATION error) that could be possible when the Remove Mesh Near Domain option is enabled.
UI: The Beginner Friendly Reminder and tooltip displayed in the Physics panel now adds a note that when this preference is enabled, some settings will be hidden.
Added: updated example motion_blur_rendering_example.blend file in the experimental builds package. This example file now uses the updated geometry nodes 'fields' workflow and removes legacy nodes.

version 9.1.2 (Oct 18 2021)

This is a minor update that mainly updates compatibility for Blender 3.0 Alpha.
Blender 3.0 Compatibility Update:
- Reminder that Blender 3.0 is still in early development and is set to release on December 3rd 2021. Please do not expect experimental versions of the FLIP Fluids addon with Blender 3.0 to be production-ready.
- Recent changes in Blender 3.0 development caused compatibility to break with the FLIP Fluids addon, and in severe cases damaged .blend files. For this reason, we strongly recommend frequent backups of your .blend files.
- It is strongly recommended to use this version of the FLIP Fluids addon with Blender 3.0 builds dated October 18 2021 or later.
- At the moment there are no known issues with this version of the FLIP Fluids addon and Blender 3.0 Alpha, but compatibility may break as Blender develops.
- Issues related to Blender 3.0 compatibility can be reported and tracked in this thread: issue #535.
Added: An example .blend file to the experimental builds package to demonstrate how to use a new Blender 3.0 feature to render true motion blur on the liquid surface (motion_blur_rendering_example.blend).
Bug Fix: Issue where objects could be incorrectly simplified into a cuboid (issue #557).
Bug Fix: Issue where temporary stat cache files would not be processed and updated upon loading a .blend file (issue #558).
Bug Fix: Error message generated if cache directory location was invalid on .blend file load.
Removed: Deprecated Check For Updates operator.

version 9.1.1 (Sep 17 2021)

This is the first experimental version since the latest stable version 1.1.0 which adds minor fixes.
Blender 3.0 Compatibility: Fixed issues related to recent changes in the Blender 3.0 API.
- Missing Documentation link in the preferences menu is now visible.
- Fixed issue where automatic toggling of Cycles visibility options upon FLIP Fluid object creation was not functioning correctly.
- Issues related to Blender 3.0 compatibility can be reported and tracked in this thread: issue #535.
MacOS Compatibility: Added potential fixes to a rare issue where the FLIP Fluids Engine was not supported on older MacOS versions. If you are experiencing any compatibility issues on any MacOS version 2014 or later, please let us know.
Bug Fix: Issue where attribute error would be generated on addon initialization if Cycles addon was not enabled (issue #552).
Bug Fix: Issue where IndexError would be generated if surface attributes were enabled, but not yet baked.
Bug Fix: Issue where unsupported object types could be set as a FLIP Fluid object (issue #556).
Bug Fix: Added workaround to issue where adding a Graph Editor Modifier to FLIP Fluids settings could bypass the property min/max values, generating an error during bake.
- This manual fix has only been added to certain settings where a user is more likely to add a graph modifier. Settings in the FLIP Fluid World panel, and settings in the Obstacle properties.
- A workaround for other settings can be to make sure the graph curve stays in the min/max range values.
- If there is a setting where you would like this fixed, please let us know.

Experimental Versions 9.0.9.x

Release notes for experimental version 9.0.9.x, which correspond to the stable FLIP Fluids Version 1.0.9 and subsequent (1.0.9a,b,c if needed). These versions contain the latest features, fixes, and improvements. Please read our Experimental Builds documentation before testing these versions.

version 9.0.9.24 (Aug 12 2021)

This version mainly adds bug fixes and small improvements. This will be the last experimental version release before the release of the next stable version (v1.1.0) next week.
Blender 3.0 Alpha Compatibility:
- This version adds necessary changes to the FLIP Fluids addon to be compatible with recent developments in Blender 3.0 Alpha. Compatibility with Blender 3.0 may break as development continues.
- Issues related to Blender 3.0 compatibility can be reported and tracked in this thread: issue #535
- Added functionality to the Automatic Command Line Bake operator (Windows Only):
  - If a simulation error occurs that stops the simulation, the operator will now attempt to automatically re-launch and resume the simulation. Certain errors such as 'Out of Memory' errors can be solved by re-launching a simulation.
  - If Blender crashes, the command line bake will try to detect the crash and attempt to re-launch Blender and the baking process.
  - The max number of re-launch attempts can be set in the FLIP Fluid Preferences menu (default = 5).
- Improved support for fracture simulations set as a FLIP Fluid Obstacle where the fracture simulation contains non-manifold geometry.
  - Instead of ignoring the entire mesh when non-manifold geometry is detected, the simulator will only ignore fractured pieces of the mesh that contain non-manifold geometry.
- Bug Fix: When baking from the command line and an error is encountered within the simulation, an error message will now be output correctly to the command line window.
- Bug Fix: (Blender 3.0) TypeError which prevents fluid surface object from being generated upon creation of a domain.
- Bug Fix: (Blender 3.0) KeyError generated upon starting a simulation.
- Bug Fix: (Blender 3.0) Immediate crash upon starting a render of a FLIP Fluids addon cache generated in Blender 2.93 or lower.

version 9.0.9.23 (Jun 30 2021)

This version mainly adds bug fixes and small improvements.
Vacation notice: Development of the FLIP Fluids addon as well as our untitled development project will be on hold during vacation until July 23rd. Until this time, fulfillment of support requests may be delayed. Thank you for your patience!
Blender Bug: Added a workaround for issue T87629 to return a 'fake' preferences with default values if the actual preferences cannot be accessed. This workaround is to support activating the FLIP Fluids addon through the command line.
Blender Bug: Reported an issue that causes render crashes when rendering vertex attributes (T88811).
Bug Fix: Crash that could be caused by using undo after activating the Create Domain operator on a selected object.
Bug Fix: Fixed incorrect render issue when 'Render > Persistent Data' option is enabled. Note: with this option enabled, rendering can be less stable. It is recommended to render through the command line if enabling this option.
Bug Fix: Fixed issue where a curve or empty type object could not be added as a force field object through the helper menu.
Bug Fix: Added missing Cache 'Match Filename' operator to helper menu.
Unfinished features: Color attribute features (and Source ID attributes) are not completely finished, but basic functionality can be accessed by enabling the 'Developer Tools' option in the FLIP Fluids Preferences menu.

version 9.0.9.22 (May 25 2021)

This version adds bug fixes and small features.
Reverted a bug fix in 9.0.9.20 (Issue where surface and whitewater materials would be removed when changing between scenes) that ended up causing large problems in material set up for the simulation mesh objects. A better fix without side-effects will need to be implemented.
Added operator to FLIP Fluid Cache panel to set the cache location to a directory based on the name of the .blend file.
Added +/- operators to the FLIP Fluid Cache panel to increment/decrement a number at the end of a cache directory, similar to the icons when saving a .blend file.
Added support for all render output image file types when using the Helper > Generate Batch File operator.
Bug Fix: fixed issue where Helper > Generate Batch File operator did not support image file prefixes in the render output location.
Bug Fix: The cache directory can no longer be set to a location directly relative to the .blend file (ex: '//').
Bug Fix: Fixed issue where liquid could be spawned with triangle line artifacts for cuboid shaped Fluid objects in high resolution simulations.

version 9.0.9.21 (May 13 2021)

This version adds preliminary support for the Blender 2.93.0 Beta MacOS Arm 64 bit version of Blender!
- The MacOS ARM build of Blender is for native support on the Apple Silicon M1 processor.
- This version of Blender can be downloaded here: https://builder.blender.org/download/
- The way that we build and package the MacOS side of the addon has changed and we are looking for feedback:
  - Please let us know if you encounter any error messages.
  - If you have access to a MacOS M1 system, feedback on whether you can run a simulation using this addon version and Blender version would be greatly appreciated.
  - If you do not have access to an M1 system, we would also appreciate feedback on whether the simulator still runs on your MacOS Intel system.
  - A 'Yes, it runs' answer is just as valuable to us as a 'No, it does not run' answer.
  - Feel free to let us know on the Blender Market, on our GitHub thread, social media pages, or through support at flipfluids.com.
Bug Fix: Fixed a FileNotFoundError when using the FLIP Fluids Helper > Generate Batch File if the render output location was set to a relative path.

version 9.0.9.20 (May 05 2021)

This version mostly adds fixes for reported issues.
Blender 3.0 Compatibility: Blender 3.0 is in early development and is set to release on August 25, 2021. At the moment, there are no known issues when using Blender 3.0 with the FLIP Fluids addon version 1.0.9b or the latest experimental version. The Blender 3.0 Cycles-X branch also seems to work after some brief testing.
- Issues related to Blender 3.0 compatibility can be reported and tracked in this thread: issue #535
Added 'Remove Mesh Near Domain' feature support for the preview mesh.
Added an option to the FLIP Fluids Preferences menu to hide the experimental build warning displayed in the physics panel.
Bug Fix: Simulation will no longer stop if a frame statistics temporary file is found to be in use and unable to be deleted (issue #529).
Bug Fix: Issue where surface and whitewater materials would be removed when changing between scenes.
- This involved many changes for how the addon sets up the viewport and render. Please let us know about any odd behavior in how the simulation is displayed.
Bug Fix: Issue where command line operators may not work if spaces are contained in the Blender executable path, specifically when located in C:/Program Files/.
Bug Fix: Fixed inconsistent UI issues (issue #533).
Bug Fix: Issue where non-mesh type objects could be selected as a custom whitewater particle object, leading to an error.
Bug Fix: Re-fixed preview rectangle artifacts issue that was introduced as a side effect by another bug fix (issue #491).
Bug Fix: Issue where the whitewater display percentage setting loaded an incorrect amount of whitewater after resuming a simulation. Notes:
- This was caused by the addon saving incorrect information to the savestates cache.
- Simulations will need to be re-baked for this fix to take effect.
Bug Fix: Issues where (harmless) error messages could be displayed when using Blender 3.0.
Known Issue: The Age and Source ID attributes are not yet supported when using the particle sheeting feature. A fix is in progress!

version 9.0.9.19 (Apr 21 2021)

This version is the first experimental build since the release of FLIP Fluids 1.0.9b (06-APR-2021).
Added geometry attribute features for the liquid surface mesh that can be enabled in the FLIP Fluid Surface panel. See Development Notes #55 on these features.
- Added a velocity attribute. After baking, the velocity vectors (in m/s) can be accessed in a Cycles Attribute Node with the name 'flip_velocity' from the Vector output. If the velocity direction is not needed, use Generate Speed Attributes instead.
- Added a speed attribute. After baking, the speed (in m/s) can be accessed in a Cycles Attribute Node with the name 'flip_speed' from the Fac output.
- Added an age attribute. After baking, the age (in seconds) can be accessed in a Cycles Attribute Node with the name 'flip_age' from the Fac output.
- Only supported in Blender 2.93.
- Only supported using the Cycles renderer. According to the Blender developers, EEVEE support will come at a later date.
- Due to a bug in Blender, these new attribute features will cause render crashes or incorrect renders. Until this is fixed, rendering from the command line will be required to prevent render crashes when using these attribute features.
- Compatibility with older .blend files: If you had tested our prototype build for velocity-based shading, you may need to fix your .blend file when using this version. To fix your file, delete all shape keys attached to the fluid_surface object.

version 9.0.9.18 (Mar 31 2021)

This version is a minor release containing only stable bug fixes and contains almost every change that will be included in the next stable release, FLIP Fluids 1.0.9b (April 6 2021).
Bug Fix: 'TypeError' that could be triggered in Blender 2.93 by pressing the F3 operator search key.
Bug Fix: Removed deprecated cache operators (Copy/Move/Rename) from being searchable and executable in the F3 operator search menu.
Bug Fix: Fixed UI issue where bake information would not be updated when using the Reset operator if the current cache directory did not exist.
Bug Fix: Fixed missing icon errors in Blender 2.79 due to icon renaming in Blender 2.8+.
Example Scene Fix: Fixed volume_force_animated_character.blend example scene issue where the fluid objects would be emitted in the wrong direction. Corrected in the example scenes file as of March 25, 2021.

version 9.0.9.17 (Mar 17 2021)

This version is a minor release containing only stable bug fixes and improvements as we get ready for the next stable release, version 1.0.9b, set during the week of April 5th. Thanks for all of your testing and reports!
Blender 2.93 Alpha support: As of the March 11th daily build, there are no know compatibility issues between the FLIP Fluids addon and Blender 2.93. Issues related to Blender 2.93 compatibility can be reported and tracked in issue #519.
Bug Fix: Error message when using command line batch baking operator if render output directory does not exist on the filesystem.
Bug Fix: UI issue where domain FLIP operator displayed the hide/show viewport/render icons in reverse order compared to regular Blender convention.
Bug Fix: Bug where using the inflow Constrain Inflow Velocity option could cause a bulge to form in the lower x/y/z corner of the domain.
Bug Fix: ValueError that could be triggered upon creating a domain if the .blend file was located on a different drive than the Blender installation.
Bug Fix: Potential issue where instanced particle objects could have Motion Blur enabled, causing longer render times in Blender 2.91+ (related to similar fix in v9.0.9.16).
Fixed: Bug where using the FLIP Fluids Helper > Solid/Wireframe operator would deselect Fluid/Inflow/Outflow objects after execution.
Changed: The FLIP Fluids Helper > Solid/Wireframe operators no longer change the render visibility of the objects. This functionality has been split into a separate row of Show/Hide Render operators that sets the render visibility of all selected objects.

version 9.0.9.16 (Mar 10 2021)

This version adds a few bug fixes and improvements.
Bug Fix: Fixed an issue where many particles could become stuck to sharp obstacle edges which could lead to an unstable simulation (issue #508).
Bug Fix: Potential fix for render crashes when the Fluid Particle Debugging or Force Field Debugging tools are enabled (issue #521).
Bug Fix: Fixed error messages in Blender 2.79 due to difference in icon names in Blender 2.8+.
Bug Fix: Fixed issue in Blender 2.91+ where rendering fluid meshes with motion blur enabled could result in longer Cycles render times.
- Note: Motion Blur Rendering of fluid surfaces or whitewater particles is not currently supported (See: Motion Blur Support).
- This fix will only apply to newly created scenes. To workaround this issue in an existing scene, select a fluid/whitewater object and disable the Object Properties > Motion Blur option (only applies if Cycles is the selected renderer).
Added a UI warning and tooltip if the Estimated Surface Tension Substeps info value exceeds the allowed Max Frame Substeps Value (Documentation).
Added viewport visibility toggles to the fluid particle, force field, and obstacle debug tools.

version 9.0.9.15 (Mar 03 2021)

Similar to the last experimental release, this version contains large structural changes in how the simulator functions which may be a potential source of bugs. Please let us know if you are experiencing any of the following issues:
- Crashes or error messages during baking.
- Out of Memory errors or simulations using an unusually large amount of memory.
- Inability to pause, resume, or upscale a simulation.
- Error messages when using a cache created by an older addon version.
Safety Factor (CFL Number) setting in the FLIP Fluid Advanced panel has moved from the Simulation Stability section to the Frame Substeps section. The Safety Factor option is more closely related to how the simulator calculates adaptive substeps.
Added an operator to the FLIP Fluid Helper sidebar menu to generate a Windows batch file (.bat) to command line render each frame of an animation one by one.
- Operator will detect already rendered frames in the output directory and disregard these from the batch file.
- Upon a render crash, the batch file will start up Blender again and begin rendering the next frame. In this way, you can minimize unrendered frames if your system is prone to render crashes.
- Can be used outside of the FLIP Fluids addon to render a sequence of frames individually. There are some bugs in Blender which can cause an animation to be rendered incorrectly and a workaround to these issues is to render each frame one by one.
Viscosity Solver Improvements
- Large structural changes to the viscosity solver code and memory layout. Please let us know about any baking crashes, error messages, or incorrect behaviour.
- Bug Fix: Fixed issue where low viscosity streams would have a velocity bias in the positive X/Y/Z direction (issue #455).
- Improved accuracy of viscosity solver setup.
- Added an Accuracy option to the viscosity solver to control the solver error tolerance.
  - Decrease to speed up baking at the cost of accuracy. Increase to improve accuracy at the cost of baking speed. High viscosity thick or stiff fluids benefit the most from increasing accuracy. Low viscosity thin fluids often work well at the lowest accuracy. Setting above a value of 4 may have greatly diminishing returns on improvement.
  - The default value of 4 is the same amount of error tolerance used internally in previous versions.
Bug Fix: Fixed issue where disabling the whitewater feature and resuming a simulation would result in invalid whitewater cache files being generated in the cache directory.
Bug Fix: Fixed typo in code that would cause an error that would prevent a helpful error message from being displayed (Pull Request Here).
Bug Fix: Fixed UI issue where the Resume From Frame X label could be displayed in red text instead of the default white.

version 9.0.9.14 (Feb 18 2021)

This is the first experimental version since release of FLIP Fluids Stable 1.0.9a (03-FEB-2021).
New system for storing and managing particles in the simulation engine (More info in development notes #47). This is a large structural change for how the simulator functions and may be a potential source of bugs. Please let us know if you are experiencing any of the following issues:
- Crashes or error messages during baking.
- Out of Memory errors or simulations using an unusually large amount of memory.
- Inability to pause, resume, or upscale a simulation.
Bug Fix: Issue where keyframing a min/max property could overwrite other min/max properties (issue #516).
Bug Fix: Updated addon code to be compatible with Python 3.9. Some Linux distributions package Blender with Python 3.9 rather than the officially supported Python 3.7.
Bug Fix: Removed extraneous debugging code that would cause (harmless) error messages in Blender 2.79.
Bug Fix: Issue where the bake operator status could hang on Calculating time remaining....

version 9.0.9.13 (Jan 27 2021)

This is a minor update that only includes small and stable changes. Assuming no large problems are found, this version will become a maintenance patch, FLIP Fluids 1.0.9a, that will contain most changes since the release of 1.0.9. Expected release of February 3, 2021.
Bug Fix: Potential crash if a curve guided force field had endcaps disabled while enabling a minimum distance for the force field.
Bug Fix: Issue where exporting an animated curve guided force field could trigger a 'Changing Topology Warning'. Note: it is okay for all current force fields to change topology.
Bug Fix: Issue where Remove Particles With Extreme Velocities could generate false-positives for a viscous fluid falling under regular gravity.
Bug Fix: Issue where keyframed quaternion or axis-angle rotation was not supported (issue #515).
Bug Fix: Issue where the baked debug tools (particle/obstacle/forcefield) would not be updated correctly if the simulation Time Scale value was set to 0.0.
Bug Fix: Potential error messages caused by the addon detecting Blender 2.9x versions incorrectly.

version 9.0.9.12 (Jan 13 2021)

This is the first experimental version since development has resumed after our winter holiday break! This update mainly involves adding minor bug fixes.
Blender 2.92 Alpha support: as of January 5th, 2021, the daily Blender builds now support the FLIP Fluids addon. In earlier 2.92 builds, a Python feature that the addon uses was missing.
- The stable FLIP Fluids 1.0.9 is also now supported in Blender 2.92 Alpha.
- Support may break as Blender 2.92 develops and issues can be tracked here: Issue #507.
Fixed bug where an incorrect frame was used in the simulation for the inflow/fluid object speed value if this value was keyframe animated.
Integrated a workaround into the addon for a long-standing Blender bug T71908 which causes keyframed render settings on the fluid meshes not to be evaluated during render. This workaround fixes:
- Issues where keyframed settings in the FLIP Fluid Display Settings panel would not take effect during render.
- Issues where the FLIP Fluids Helper > Override Frame Playback feature would not function during render.
- Issues where an Ocean Modifier attached to the fluid meshes would not be animated during render.
Added three new example scenes by popular request (Animation previews, Example Scene Descriptions).
- These scenes are also supported in the stable FLIP Fluids version 1.0.9.
New Documentation: Addon Installation Troubleshooting.
- How to verify your FLIP Fluids installation file.
- How to locate your Blender addons directory.
- How to verify your FLIP Fluids Blender installation.
- How to clean up your Blender addons directory in the case of an incorrect installation.
- How to manually install the FLIP Fluids addon.

version 9.0.9.11 (Dec 16 2020)

This is the first experimental version since the stable version release of FLIP Fluids 1.0.9. Update mainly involves adding minor bug fixes reported after the stable release.
Notice: Development of the FLIP Fluids addon will be on winter break during December 17th, 2020 - January 3rd, 2021. Have a happy holidays and a wonderful new year!
Compatibility notes:
- Due to a bug in Blender versions 2.80, 2.81, and 2.82, it will no longer be possible for us to support MacOS in these three versions. The FLIP Fluids addon on MacOS will still be supported in Blender 2.79, 2.83+, and 2.9+.
- Blender 2.92 is not yet supported. This version of Blender is still in early development and we will need to wait until this becomes more stable in order to add support (track issue here).
Added a filesystem protection layer to enforce that all file removal operations are functioning correctly.
- All file removal operations must pass through this layer which detects bugs related to human/development error.
- Enforces that files can only be deleted within the current cache directory or the FLIP Fluids addon scripts directory.
- Enforces that directories cannot be deleted recursively (ex: files within subdirectories of a subdirectory cannot be deleted).
- Enforces that files can only be deleted if they contain an extension contained in a whitelist of extensions used by the FLIP Fluids addon.
  - Extension whitelist: .backup, .bbox, .bobj, .data, .ffd, .fpd, .info, .md, .png, .preset, .sim, .sqlite3, .state, .txt, .wwp
Bug Fix: Addon will no longer allow the FLIP Fluid current cache directory to be set as blank and will be set as a reasonable default value.
Bug Fix: FLIP Fluids Helper menu command line tool operators displayed incorrectly on MacOS and Linux (issue #505).
Bug Fix: FLIP Fluids Helper menu command line tool Copy to Clipboard operators were not functioning on MacOS and Linux (issue #505).
Bug Fix: Fixed potential Out of Memory error that could be triggered if a force field object is located outside of the domain.
Bug Fix: Fixed potential issue where the FLIP Fluid surface or whitewater object could lose it's material after reseting a bake.
Bug Fix: Fixed issue where inflow particles could be seeded in an unnatural pattern (issue #509).

version 9.0.9.10 (Nov 23 2020)

Update mainly involves testing and polishing. All features in this experimental version will be moved in the next stable 1.0.9 version release (November 26th 2020).
- New experimental features will continue in the next experimental version 9.0.9.11.
- More force field features will be added to the stable versions (ex: 1.0.9a or 1.1.0) as they are tested and are considered stable.
Added missing Add Force object in the FLIP Fluids Helper Menu.
When the addon creates a new domain object using the Create Domain operator, the origin will now be set at the object's center.
Added a UI notification to the FLIP Fluid Simulation panel to notify user in the case that the simulation will be upscaled (increasing resolution on resume).
Rearranged settings in the FLIP Fluid Simulation panel to group settings related to setting the simulation grid in one place.
- Added a Grid Info section to display info about the simulation grid including tooltips to help explain the simulation grid.
  - 3D voxel dimensions
  - 3D physical dimensions
  - Voxel size
  - Voxel count
- Copied option to display grid visualization in the Grid Info section.
- Copied option to set World Scale in the FLIP Fluid Simulation panel.
Force Field Resolution option is now set to Ultra by default. This is the recommended value for force fields that are static.
The FLIP Fluid Preset panel and features are now hidden by default as this feature has been deprecated for more than a year. These features can still be enabled in the FLIP Fluid Preferences menu. Read More Here.
FLIP Fluid Preferences options are now greyed out instead of hidden in the case that the user has just installed the addon but has not restarted Blender. This is to show that there are preferences that exist in this menu.
Viewport/Render display options (final/preview/none) in the FLIP Fluid Display Settings panel are now displayed in a full list rather than a drop down menu.
FLIP Fluid Helper Menu now contains an option to set the viewport display (final/preview/none) for both the fluid surface and whitewater meshes separately.
Bug Fix: Fixed major crash issue on MacOS that could be triggered by updating simulation settings on resuming a bake.
Bug Fix: Fixed potential Index out of range crash when using a point force field in combination with a small world scale.
Bug Fix: Fixed bug where FLIP Fluid Simulation panel would not be drawn in the case that the user has run out of drive space during the previous simulation.
Bug Fix: Fixed issue where using the Organize Outliner operator could leave FLIP Fluid objects in the incorrect collection if the object had changed the simulation type.
New Documentation: notes on potential feature of Motion Blur Support on Alembic Exports.

version 9.0.9.09 (Nov 04 2020)

Update mainly consists of bug fixes and a feature to upscale simulation resolution on resume.
Added functionality to upscale a simulation to an increased resolution on resuming the bake. Notes:
- If resuming a bake at a higher resolution, the simulator will automatically upscale the simulation data to the new resolution.
- Useful if you have a simulation that takes some time to generate motion before you want to render the animation. For example, the initial motion and fill of a river could be simulated at a low resolution quickly, and then upscaled and continued at a higher final resolution.
- Functionality to downscale a simulation to a lower resolution will be added at a later date.
Material UI dropdown lists have been copied from the FLIP Fluid Material panel into the FLIP Fluid Display Settings panel.
Bug Fix: Fixed issue where the simulation mesh could be loaded into the viewport during animated object export, causing a very slow export process.
Bug Fix: Fixed issue where Empty type objects could be exported to incorrect locations within the simulator.
Bug Fix: Fixed issue where implementation and functionality of the Disable Changing Topology Warning was missing.
Bug Fix: Fixed issue where rectangle artifacts could appear in the fluid surface preview mesh (issue #491).

version 9.0.9.08 (Oct 22 2020)

Update mainly consists of changes to the UI including bug fixes, organization, and small workflow features.
Blender Market product downloads have been renamed to use more consistent naming format that includes the date that the file was last updated (See FLIP Fluids Downloads).
Added a README.html file to the Blender Market product downloads that contains info and links for how to get started with the addon.
Added Force Re-Export On Next Bake feature for FLIP Fluid/Obstacle/Inflow/Outflow/ForceField objects. Notes:
- When enabled, this option will force the addon to re-export the object's mesh data the next time that the user bakes or resumes the simulation.
- This option overrides the Skip Re-Export option.
- After the object has been re-exported, the force export option will be automatically disabled.
- This option is only applicable if the _Skip Re-Export option is enabled.
- Useful for if you have a complex animation or object with a lot of geometry with the Skip Re-Export option enabled to save time during export. Use this option if you make an update to your mesh and want to easily mark the object to update the next time you bake/resume the simulation.
FLIP Fluids Helper Menu organization and cleanup - many changes based on user feedback, thanks!
- Submenus can now be collapsed/expanded.
- Renamed submenus and rearranged operators within submenus.
- Check For Updates operator has been removed from the Helper Menu and is now only available in the FLIP Fluids Preferences Menu.
- Bake Simulation submenu now includes the current cache directory.
- Added prompt/warning to Bake Simulation submenu to warn that the .blend file has not been saved. Includes operator to open the save file menu.
  - Note: it is not required to save the .blend file in order to run a simulation, but some addon features were designed to work better if the file is saved.
FLIP Fluid Simulation > Settings and Mesh Export submenu organization and cleanup.
- Submenu can now be expanded/collapsed.
- Object list can now be filtered to display objects by motion type: Static, Keyframed, Animated, or all objects.
- Added the new Force Re-Export On Next Bake option to be displayed in the list.
- Added operators to Enabled or Disable Skip Re-Export or Force Re-Export On Next Bake_ options for all objects in list.
The Enable Stable Rendering operator now toggles to Disable Stable Rendering if enabled, as a quick way to undo the operator (Blender 2.8+ only).
Obstacle Friction list in FLIP Fluid World panel can now be expanded/collapsed.
Default name of the domain object has been renamed to FLIP Domain when using the Create Domain operator.
Whitewater Wavecrest/Turbulence/Dust Emission Rate settings have been renamed to Max Wavecrest/Turbulence/Dust Emission Rate as better descriptions for the settings.
Bug Fix: Fixed error that could be triggered if the Organize Outliner operators were used without a Domain object in the the scene.
Bug Fix: Fixed bug where stray FLIP Fluid objects could remain behind after using the FLIP Objects to Collections operator.
Bug Fix: Fixed bug where toggling render visibility for a FLIP Force Field object would not also toggle Cycles ray visibility.
Bug Fix: Fixed bug in Blender versions 2.9+ where toggling a FLIP object's render visibility would not update the object visibility in the viewport rendered mode.
Bug Fix: Fixed bug where command line tools would not be displayed for MacOS/Linix operating systems.
Bug Fix: Fixed bug in versions of Blender 2.9+ where newly created Domain objects would not be highlighted after using the Create Domain operator.

version 9.0.9.07 (Oct 14 2020)

A minor update that mainly consists of an Override Frame feature similar to Blender's Alembic Mesh Cache setting and some bug fixes.
Added Override Frame settings to FLIP Fluids Helper Menu that works similar to the setting of the same name in Blender's Alembic Cache modifier.
- TIP: Keyframing the override frame number can allow for complex control over simulation playback (ex: start/stop freeze frames, reverse animation)
- The addition of this feature caused some settings to be re-arranged in the Helper Menu and some settings have moved into a separate Simulation Playback submenu (Documentation).
The FLIP Meshes to Collections operator in the Helper Menu now groups all of the whitewater meshes into a single WHITEWATER collection instead of separating them each into separate collections.
Bug Fix: Fixed error that could be triggered when using the FLIP Objects to Collections operator in the Helper Menu.
Bug Fix: Fixed potential crash issues that could be triggered when using Blender's Undo (Ctrl+Z) after using the Create Domain operator in the Helper Menu.

version 9.0.9.06 (Oct 7 2020)

This version mainly consists of requested features to help with your simulation workflow.
Added functionality to link exported geometry data from another cache directory in FLIP Fluid Cache panel (Documentation).
- Use if you want to re-use exported geometry data that is located in another cache directory.
- Useful if you have a lot of animated geometry data in your scene that you do not want to re-export.
- Useful for if you have multiple caches from the same scene for testing different simulation settings.
Added 'Create Domain' operator to FLIP Fluids Helper Menu to generate a domain depending on the context of what type of objects are selected and in your scene (Documentation).
Added operators to FLIP Fluids Helper Menu to help organize your simulation objects in the Blender Outliner (Documentation).
- Separate your FLIP Fluid objects into collections by type
- Separate the generated simulation methods into collections (useful for creating view layers)
Added operators to FLIP Fluids Helper Menu to select all simulation objects of a certain type (Obstacle/Fluid/Inflow/Outflow/ForceField) (Documentation).
New Documentation: Whitewater Rendering Tips.

version 9.0.9.05 (Sep 30 2020)

Added optimizations that can speed up simulation baking for medium to large simulations by 10% - 15%
Addon now includes two versions of the fluid simulation engine that can be switched in the addon preferences menu. Notes:
- Engine Debug Mode enabled: uses a debugging version of the simulation that can generate error messages after a simulation crash, but runs slightly slower
  - This is the version of the simulation engine used in versions older than v9.0.9.05
- Engine Debug Mode disabled: includes performance optimizations, but is unable to generate error messages after a simulation crash
  - If you are experiencing a persistent simulation crash, switch to the debugging engine and resume/re-run simulation to check for error messages
- Running the debug engine or normal engine will not affect the results of the simulation
Addon can now be built/compiled using a Python script (build.py) rather than running CMake and GNU Make directly. The new Python script automates building both versions of the fluid simulation engine.
Addon packaging and distribution for Windows/MacOS/Linux is now automated to reduce issues related to human-error
Fixed potential crash that can be triggered when using Surface, Volume, or Curve Guided force fields
Default value change: FLIP Fluid Simulation -> Update Settings on Resume is now enabled by default
Default value change: FLIP Fluid Surface -> Subdivisions is now set to 1 by default
- Note: this produces a more desireble mesh with less artifacts and issues, but takes some extra time to compute. If you want to maximize baking speed during testing, set this value to 0
New Documentation: FLIP Fluids Helper Menu
New Documentation: FLIP Fluids Preferences Menu
New Documentation: Current Status of the Preset System

version 9.0.9.04 (Sep 16 2020)

Added curve guided force field mode See documentation.
Added options to Fluid/Inflow object to emit fluid from the object's negative local axis (in addition to the existing positive axis options).
Fixed export error that could be triggered by exporting an Empty type object as a force field.
Added UI warnings if the type of Blender object is not suitable for the selected force field mode (Ex: using an Empty type object as a Surface Force).
Added note to Inflow Enabled tooltip that this option can be disabled to stop fluid emission.
Performance improvements in handling FLIP Fluid Obstacle objects.
Performance improvements in grid initialization.

version 9.0.9.03 (Sep 2 2020)

Mesh data export system has been rewritten and exported scene mesh data types are now stored in an SQLite3 database rather than directly on the filesystem (Detailed notes in Development Update #28)
- This will be a likely source of bugs as a major portion of code had been rewritten. The following is a list of some things to test:
- Are your mesh objects appearing in the correct place during simulation?
  - For static objects (not moving)?
  - For keyframed objects (animated with simple rotation/location/scale or f-curves)?
    - For all of Blender's rotation modes (Euler, Axis Angle, Quaternion)?
  - For animated objects (complex animation such as parenting, armatures, deformation)?
- Are you able to start your simulation without error messages?
- Are you able to stop and resume your simulation?
  - Is the 'Update Settings on Resume' feature still functioning correctly?
- Are you able to reset or delete your cache without errors?
- Are Inflow/Fluid objects with target objects emitting in the correct direction?
  - When the target is an Empty type object?
  - When the target is a Mesh type object?
- Is the Skip Re-Export feature still functioning correctly?
- Is the FLIP Fluid Surface 'Meshing Volume' feature still functioning correctly?
- Is command line baking still functioning correctly?
- Are your older .blend files (v1.0.8a and higher) and caches still running and loading correctly?
- If you notice any undesireable changed behaviour or bugs between versions, please let us know!
- If you are interested in viewing/debugging the database contents, the SQLite3 database file can be found in cache_directory/export/export_data.sqlite3. A graphical SQLite3 viewer such as DB Browser for SQLite can be used.
Added functionality to Skip Re-Export of static and keyframed meshes in addition to skipping animated meshes.
Added functionality for Inflow/Fluid objects to emit fluid in the direction of the object's local axis.
Fixed issue where inline force field documentation links would not be consistently displayed when submenu was collapsed.
New Complete Guide Episode: Mastering FOAM (part 3a)

version 9.0.9.02 (Aug 5 2020)

Latest development update covering this development week: #27
- Notice: Ryan is back from vacation! Daily support and experimental updates have resumed!
Added Domain bake operators to the FLIP Fluid toolshelf menu.
Fixed error where some fixes mentioned in previous experimental release notes were not actually distributed in the releases.
Fixed compatibility issues on MacOS systems
Fixed bug that could cause a crash if viscosity feature was enabled while simulating small amounts of fluid.
Removed Preserve Foam options from FLIP Fluid Whitewater UI. These settings were not working as expected and are no longer needed.
Updated Documentation: Scene Troubleshooting: Fluid behaviour changes when increasing resolution.
New Tutorial: Episode Eight: Layering Fluid to Make Delicious Sweets.

version 9.0.9.01 (Jul 6 2020)

Latest development update covering this development week: #26
- Notice: Ryan will be on vacation starting July 6th. There will be reduced customer support during this time, but you should receive a response within a few days. Regular development and daily support will resume on July 27th. Thank you for your patience!
Replaced model dragon model in point_force_dragon.blend example scene with a rhino statue. Unbeknownst to us, the dragon model is a cultural symbol and deforming it with fluid simulation can be seen as disrespectful. We apologize for this mistake and will be more careful int he future.
Fixed incorrect setting in volume_force_animated_character.blend example scene where the fluid would drop down immediately instead of following the character (gravity was set to -9.81 instead of 0.0)
Tuned internal settings for the Volume Force Object for improved UX
Added missing force field documentation links to UI (option to display documentation links in UI can be found in addon preferences menu)
Fixed a bug that could cause a crash if a surface/volume force contained all vertices outside of the domain
Fixed error where source code was not distributed with experimental build
Edited force field documentation topics for changes to new build

version 9.0.9.00 (Jun 30 2020)

Added force field mode: Point Force, a force that directs fluid towards a single point.
Added force field mode: Surface Force, a force that directs fluid towards an object's surface. See development update #13, #18, #19, and #20 for detailed information.
Added force field mode: Volume Force, a force that directs fluid towards an the interior of an object's volume. See development update #21 and #22 for detailed information.
Added force field grid resolution to FLIP Fluid World panel. See development update #22 for detailed information.
Added 'Enable Adaptive Time Stepping for Force Field' option to FLIP Fluid Advanced panel (similar to it's Obstacle counterpart).
Added force field debug visualizer to FLIP Fluid Debug panel. See development update #13 for detailed information.
Added new example scenes for force field features.
Added exponent precision editing for viscosity value.
Added exponent precision editing for surface tension value.
Added preferences option to rename the FLIP Fluids toolshelf panel name.
Added preferences option to display links to relevant documentation in the UI.
Added UI reminder to display if the preferences 'Beginner Friendly Mode' is activated.
Subsections of the UI panel can now be collapsed (Whitewater/World/Debug panels).
Duplicated whitewater particle size option from FLIP Fluid Display Settings panel to FLIP Fluid Whitewater panel.
Updated for compatibility with latest version of OctaneRender.
Updated whitewater tooltips.
Removed Rigid/Deformable mesh option for Inflow object. The simulator will now automatically detect whether the object is rigid or deformable.
Fixed issue where changing particle size in the FLIP Fluid Debug particle debugging tool would not affect the draw size.
Fixed issue that was causing inflow object to require too much memory. More info in development update #14.
Fixed issue where Strawberry Splash example scene was not compatible with newer versions of Blender.
Fixed bug where a rare divide-by-zero error could cause the simulation to collapse in on itself.
Fixed issue where a mesh containing a zero-area triangle could cause a crash.
Fixed issue where an Attribute Error could be displayed when selecting the Domain object.
Fixed possible FLIP Fluid Stats alignment issue when selecting a frame that was outside of the cache range.
Fixed issue where FLIP Fluid Stats panel could display out-of-date info after a cache reset.
Fixed issue where FLIP Fluid toolshelf menu was missing operator to select the whitewater dust object.
Improved accuracy of surface tension calculations to improve stability (prevent blow-ups).
Improved multithreaded performance of adding new fluid particles into simulation domain.
Documentation: Updated installation instructions using Blender 2.8x screenshots.
Documentation: Limitations of the FLIP Fluids addon.
Documentation: Expanded CPU Usage Topic.
Documentation: What is the difference between Blender's Mantaflow fluid simulator and the FLIP Fluids addon.
Documentation: Does my obstacle object need to be completely contained by the domain?
Documentation: Tips for Creating Ship Simulations.
New Tutorial Series: FLIP Fluids addon: The Complete Guide.

Experimental Versions 9.0.6.x

Release notes for experimental versions 9.0.6.x, which correspond to the stable FLIP Fluids 1.0.6

version 9.0.6.1 (Sep 27 2019)

Added support for Blender 2.81
Added reminder in the addon installation/preferences menu to complete installation by restarting Blender. See Installation Instructions.
Added warning about Blender 2.80 bugs to the addon installation/preferences menu and system console output. See Blender 2.80 known issues.
Added a reminder to prevent render crashes by locking interface in Blender 2.8x to addon installation/preferences menu and system console output
Added monochromatic FLIP Fluids icon for Blender 2.8x
Fixed issue that could cause frequent Blender 2.8x crashes during render, Alembic export, and rigid/cloth simulation baking (issue #403)
Fixed bug where Inflow 'Substep Emissions' value could not be keyframed
Fixed TypeError that could be triggered at the end of simulation baking (issue #469)
Fixed bug where console output would still be displayed during mesh export when the 'Display Console Output' option was disabled
Reduced amount of particle meshing artifacts on boundary of domain
Addon no longer automatically deletes the FLIP Fluids cache when closing an unsaved .blend file
Addon now automatically adds a smooth modifier (set to 0 iterations) to the fluid mesh objects
Addon will now display an error if a user attempts to bake a simulation before completing installation

version 9.0.6.0 (Jun 05 2019)

This is the initial version of the 9.0.6 experimental branch. This branch will eventually be merged into the next stable 1.0.6 version.
Added operators to toolbox menu to automatically launch command line baking and rendering processes (Feature only supported on Windows)

version 9.0.5.5 (May 17 2019)

Try it out! This version is considered stable and 'production ready' as long as you are using Blender 2.79. See Blender 2.80 known issues.
Fixed addon errors in Blender 2.80 due to recent API change (issue #448)

version 9.0.5.4 (May 09 2019)

Try it out! This version is considered stable and 'production ready' as long as you are using Blender 2.79. See Blender 2.80 known issues.
This versions is NOT compatible with older FLIP Fluids cache directories. Please use a newly create cache directory when testing this version.
Added meshing options to remove parts of surface mesh near the domain boundary
Added meshing options to set offset for fluid-solid mesh interface
Added meshing feature to set a custom object as a meshing volume. Only fluid inside of this object will be meshed.
Added advanced option to enable particle jittering for surface particles (issue #435)
Added option to skip re-exporting animated meshes
Added settings and option to set a custom baking frame range instead of using the timeline start/end values
Added a savestates feature which gives the ability to rollback a simulation and resimulate from an earlier frame
Added functionality to set a sheeting effect strength multiplier against individual obstacles
Added a 'Beginner Friendly Mode' to preferences that limits UI to only show the most basic and commonly used parameters
Fixed bug where custom particle drawing would not be reset after a cache reset (issue #422)
Fixed bug that could cause a sudden Blender crash when using 'Enable Sheeting Effects' (issue #425)
Fixed bug where custom logo icon would not be loaded (issue #427)
Fixed bug where the intersection between inversed obstacles would be computed as solid instead of empty
Fixed issue where Blender could crash during animated mesh export (issue #401)
Fixed bug where surface tension simulations could 'explode' (issue #420)
Fixed Linux/MacOS bug where a simulation could stop in the middle of baking. Huge thanks to Christian Schwarz for helping us solve this issue!
Improved support and compatibility for loading .blend files created in older FLIP Fluids versions
Improved speed and stability of animated mesh export (issue #401)
Performance improvements
Simulation stability improvements

version 9.0.5.3 (Feb 01 2019)

Added support for missing features in Blender 2.80 (issue #404)
Added sheeting effects feature to World panel (Documentation)
Added 'Surface Tension Stability' parameter to World panel (Documentation)
Misc material and preset library fixes
Fixed bug where particles could escape the domain and trigger an 'Out of Range' error (issue #415)
Fixed precision error what could cause fluid meshes to be scaled incorrectly (issue #414)
Fixed bug where debug information would be drawn when domain object is hidden or not on selected layer (issue #416)
Fixed bug where estimated surface tension substeps could have a negative value (issue #417)
Fixed bug where the 'Reload Frame' operator could ignore reloading a frame (issue #419)
Fixed bug where simulation could crash when resuming a bake
Setting inflow 'Substep Emissions' to 0 will cause the inflow only emit fluid on the first substep of a frame (Documentation)
Updated surface tension parameter to a more appropriate/stable default value
Moved 'Surface Tension Safety Factor' to World panel as 'Surface Tension Accuracy' (Documentation
Obstacle 'Expand' setting now has small soft min/max value restrictions to guide users towards smaller values (Documentation
Improved collisions with animated obstacles

version 9.0.5.2 (Dec 24 2018)

Fixed addon install error in Blender 2.80 due to API change (issue #408)
Fixed 'Value must be greater or equal to zero' error that could be triggered if domain bounding box is too thin (issue #397)
Fixed bug where deleted objects could be exported to the simulator (issue #405)
Improved simulation handling of thin obstacles to prevent leaking
'Check for Updates' operator now displays release notes for experimental versions
Performance improvements

version 9.0.5.1 (Dec 13 2018)

Added support for Blender 2.80 (issue #404)
Fixed bug where Blender could crash while rendering in Cycles with the viewport open (issue #403)
Fixed bug where copper preset could be loaded as coffee preset
Added checkbox to Presets Panel to allow auto assigning presets
Updated default whitewater spray drag coefficient to add more drag to spray particles
Rolled back some stability improvements that were causing volume increase (issue #326)
Meshing improvements
Performance improvements

version 9.0.5.0 (Nov 19 2018)

Added feature to control amount of whitewater generated by Obstacle objects (issue #385)
Added a surface tension solver (issue #388)
Added new surface tension example scenes (Documentation)
Updated Whitewater panel UI with Basic/Advanced settings modes (issue #384)
Fixed 'ResourceWarning' error when disabling and re-enabled addon
Fixed bug that would cause bumpy mesh artifacts on edges of domain (issue #380)
Fixed bug where bake would continue to run after closing Blender (issue #361)
Performance improvements
Simulation stability improvements

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