UnrealBloomPass: Use premultiplied alpha and additive blending (#32521)

examples/jsm/postprocessing/UnrealBloomPass.js

@@ -1,9 +1,8 @@
 import {
+	AdditiveBlending,
 	Color,
-	CustomBlending,
 	HalfFloatType,
 	MeshBasicMaterial,
-	OneFactor,
 	ShaderMaterial,
 	UniformsUtils,
 	Vector2,
@@ -188,11 +187,8 @@ class UnrealBloomPass extends Pass {
 			uniforms: this.copyUniforms,
 			vertexShader: CopyShader.vertexShader,
 			fragmentShader: CopyShader.fragmentShader,
-			blending: CustomBlending,
-			blendSrc: OneFactor,
-			blendDst: OneFactor,
-			blendSrcAlpha: OneFactor,
-			blendDstAlpha: OneFactor,
+			premultipliedAlpha: true,
+			blending: AdditiveBlending,
 			depthTest: false,
 			depthWrite: false,
 			transparent: true