WebGLRenderer: Fix ImmediateRenderObject with vertex colors. (#21602)

src/renderers/WebGLRenderer.js

@@ -1468,7 +1468,7 @@ function WebGLRenderer( parameters ) {
 		const environment = material.isMeshStandardMaterial ? scene.environment : null;
 		const encoding = ( _currentRenderTarget === null ) ? _this.outputEncoding : _currentRenderTarget.texture.encoding;
 		const envMap = cubemaps.get( material.envMap || environment );
-		const vertexAlphas = material.vertexColors === true && object.geometry.attributes.color && object.geometry.attributes.color.itemSize === 4;
+		const vertexAlphas = material.vertexColors === true && object.geometry && object.geometry.attributes.color && object.geometry.attributes.color.itemSize === 4;
 
 		const materialProperties = properties.get( material );
 		const lights = currentRenderState.state.lights;

src/renderers/webgl/WebGLPrograms.js

@@ -208,7 +208,7 @@ function WebGLPrograms( renderer, cubemaps, extensions, capabilities, bindingSta
 
 			vertexTangents: ( material.normalMap && material.vertexTangents ),
 			vertexColors: material.vertexColors,
-			vertexAlphas: material.vertexColors === true && object.geometry.attributes.color && object.geometry.attributes.color.itemSize === 4,
+			vertexAlphas: material.vertexColors === true && object.geometry && object.geometry.attributes.color && object.geometry.attributes.color.itemSize === 4,
 			vertexUvs: !! material.map || !! material.bumpMap || !! material.normalMap || !! material.specularMap || !! material.alphaMap || !! material.emissiveMap || !! material.roughnessMap || !! material.metalnessMap || !! material.clearcoatMap || !! material.clearcoatRoughnessMap || !! material.clearcoatNormalMap || !! material.displacementMap || !! material.transmissionMap,
 			uvsVertexOnly: ! ( !! material.map || !! material.bumpMap || !! material.normalMap || !! material.specularMap || !! material.alphaMap || !! material.emissiveMap || !! material.roughnessMap || !! material.metalnessMap || !! material.clearcoatNormalMap || !! material.transmissionMap ) && !! material.displacementMap,