WebGPURenderer: Fix blending opacity in shadows (#30081)

* fix blending opacity in shadows

* cleanup

* Update webgpu_shadowmap_opacity.jpg

* Update webgpu_shadowmap_opacity.jpg

src/nodes/lighting/ShadowNode.js

@@ -11,7 +11,7 @@ import NodeMaterial from '../../materials/nodes/NodeMaterial.js';
 import QuadMesh from '../../renderers/common/QuadMesh.js';
 import { Loop } from '../utils/LoopNode.js';
 import { screenCoordinate } from '../display/ScreenNode.js';
-import { HalfFloatType, LessCompare, NoBlending, RGFormat, VSMShadowMap, WebGPUCoordinateSystem } from '../../constants.js';
+import { HalfFloatType, LessCompare, RGFormat, VSMShadowMap, WebGPUCoordinateSystem } from '../../constants.js';
 import { renderGroup } from '../core/UniformGroupNode.js';
 import { viewZToLogarithmicDepth } from '../display/ViewportDepthNode.js';
 import { objectPosition } from '../accessors/Object3DNode.js';
@@ -53,7 +53,6 @@ const getShadowMaterial = ( light ) => {
 		material.colorNode = vec4( 0, 0, 0, 1 );
 		material.depthNode = depthNode;
 		material.isShadowNodeMaterial = true; // Use to avoid other overrideMaterial override material.colorNode unintentionally when using material.shadowNode
-		material.blending = NoBlending;
 		material.name = 'ShadowMaterial';
 
 		shadowMaterialLib.set( light, material );

src/renderers/common/Renderer.js

@@ -1655,6 +1655,7 @@ class Renderer {
 
 			overrideMaterial.alphaTest = material.alphaTest;
 			overrideMaterial.alphaMap = material.alphaMap;
+			overrideMaterial.transparent = material.transparent || material.transmission > 0;
 
 			if ( overrideMaterial.isShadowNodeMaterial ) {