[v3.8.6] Fix a mangleProperties issue which is caused by using as any in trail.ts.

cocos/particle/renderer/particle-system-renderer-base.ts

@@ -107,7 +107,7 @@
     public setVertexAttributes (): void {
         if (this._model) {
             this.updateVertexAttrib();
             this._model.setVertexAttributes(this._renderInfo!.renderMode === ParticleRenderMode.Mesh ? this._renderInfo!.mesh : null, this._vertAttrs);
         }
     }
 
@@ -128,7 +128,7 @@
     }
 
     public updateTrailMaterial (): void {}
-    public getDefaultTrailMaterial (): null { return null; }
+    public getDefaultTrailMaterial (): Material | null { return null; }
     public abstract getParticleCount (): number;
     public abstract getFreeParticle (): Particle | null;
     public abstract onMaterialModified (index: number, material: Material): void;

cocos/particle/renderer/particle-system-renderer-cpu.ts

@@ -243,7 +243,7 @@ export default class ParticleSystemRendererCPU extends ParticleSystemRendererBas
         return this._particles!.add();
     }
 
-    public getDefaultTrailMaterial (): any {
+    public getDefaultTrailMaterial (): Material | null {
         return this._defaultTrailMat;
     }
 

cocos/particle/renderer/trail.ts

@@ -454,7 +454,7 @@ export default class TrailModule {
     public updateMaterial (): void {
         if (this._particleSystem) {
             this._material = this._particleSystem.getMaterialInstance(1)
-                || (this._particleSystem.processor as any)._defaultTrailMat;
+                || this._particleSystem.processor.getDefaultTrailMaterial();
             if (this._trailModel) {
                 this._trailModel.setSubModelMaterial(0, this._material!);
             }