Fix particle bugs

packages/core/src/Renderer.ts

@@ -323,6 +323,10 @@ export class Renderer extends Component implements IComponentCustomClone {
    * @internal
    */
   _prepareRender(context: RenderContext): void {
+    if (this._renderFrameCount !== this.engine.time.frameCount) {
+      this._update(context);
+    }
+
     const virtualCamera = context.virtualCamera;
     const cameraPosition = virtualCamera.position;
     const boundsCenter = this.bounds.getCenter(Renderer._tempVector0);
@@ -334,11 +338,6 @@ export class Renderer extends Component implements IComponentCustomClone {
       this._distanceForSort = Vector3.distanceSquared(boundsCenter, cameraPosition);
     }
 
-    // Update once per frame per renderer, not influenced by batched
-    if (this._renderFrameCount !== this.engine.time.frameCount) {
-      this._updateRendererShaderData(context);
-    }
-
     this._render(context);
 
     // union camera global macro and renderer macro.
@@ -411,7 +410,10 @@ export class Renderer extends Component implements IComponentCustomClone {
    */
   _batch(elementA: SubRenderElement, elementB?: SubRenderElement): void {}
 
-  protected _updateRendererShaderData(context: RenderContext): void {
+  /**
+   * Update once per frame per renderer, not influenced by batched.
+   */
+  protected _update(context: RenderContext): void {
     const { layer } = this.entity;
     this._rendererLayer.set(layer & 65535, (layer >>> 16) & 65535, 0, 0);
   }

packages/core/src/mesh/SkinnedMeshRenderer.ts

@@ -154,7 +154,7 @@ export class SkinnedMeshRenderer extends MeshRenderer {
     this._blendShapeWeights && (target._blendShapeWeights = this._blendShapeWeights.slice());
   }
 
-  protected override _updateRendererShaderData(context: RenderContext): void {
+  protected override _update(context: RenderContext): void {
     const { skin } = this;
     if (skin?.bones.length > 0) {
       skin._updateSkinMatrices(this);
@@ -210,7 +210,7 @@ export class SkinnedMeshRenderer extends MeshRenderer {
       }
     }
 
-    super._updateRendererShaderData(context);
+    super._update(context);
   }
 
   /**

packages/core/src/particle/ParticleRenderer.ts

@@ -159,14 +159,6 @@ export class ParticleRenderer extends Renderer {
       return;
     }
 
-    const generator = this.generator;
-    generator._update(this.engine.time.deltaTime);
-
-    // No particles to render
-    if (generator._firstActiveElement === generator._firstFreeElement) {
-      return;
-    }
-
     super._prepareRender(context);
   }
 
@@ -200,7 +192,15 @@ export class ParticleRenderer extends Renderer {
     }
   }
 
-  protected override _updateRendererShaderData(context: RenderContext): void {
+  protected override _update(context: RenderContext): void {
+    const generator = this.generator;
+    generator._update(this.engine.time.deltaTime);
+
+    // No particles to render
+    if (generator._firstActiveElement === generator._firstFreeElement) {
+      return;
+    }
+
     const shaderData = this.shaderData;
     shaderData.setFloat(ParticleRenderer._lengthScale, this.lengthScale);
     shaderData.setFloat(ParticleRenderer._speedScale, this.velocityScale);

packages/core/src/shaderlib/particle/color_over_lifetime_module.glsl

@@ -22,7 +22,7 @@
             float time = key.x;
             if(alphaAge <= time){
                 if(i == 0){
-                    value.a = colorKeys[0].y;
+                    value.a = alphaKeys[0].y;
                 }
                 else {
                     vec2 lastKey = alphaKeys[i-1];