Fix distortion in p5 integration

[davepagurek]

Currently, cubes rendered via the p5 integration show spherical distortion:

This is because the p5 integration was inverting the model view matrix before drawing the sphere that we render Shader Park onto. However, when drawing a sphere, p5 updates the model view matrix again to apply a scale. The camera information passed to Shader Park does not have this scale, which results in incorrect rays.

I've updated the code to no longer do the matrix inversion in Javascript. This eliminates the need to grab the model view matrix ahead of time, and instead only uses the correct uMVMatrix that p5 passes in.

Updated:

Live: https://editor.p5js.org/davepagurek/sketches/HM9sUI8Qh

[PWhiddy]

Perfect thank you!