PMREMGenerator: Align GGX_SAMPLES across renderers and clean up.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: mrdoob

src/extras/PMREMGenerator.js

@@ -532,7 +532,7 @@ class PMREMGenerator {
 		const incrementalRoughness = Math.sqrt( targetRoughness * targetRoughness - sourceRoughness * sourceRoughness );
 
 		// Apply blur strength mapping for better quality across the roughness range
-		const blurStrength = 0.0 + targetRoughness * 1.25;
+		const blurStrength = targetRoughness * 1.25;
 		const adjustedRoughness = incrementalRoughness * blurStrength;
 
 		// Calculate viewport position based on output LOD level

src/renderers/common/extras/PMREMGenerator.js

@@ -41,7 +41,7 @@ const EXTRA_LODS = 6;
 const BLUR_SAMPLES = 20;
 
 // GGX VNDF importance sampling configuration
-const GGX_SAMPLES = 512;
+const GGX_SAMPLES = 256;
 
 const _flatCamera = /*@__PURE__*/ new OrthographicCamera( - 1, 1, 1, - 1, 0, 1 );
 const _cubeCamera = /*@__PURE__*/ new PerspectiveCamera( 90, 1 );
@@ -125,7 +125,7 @@ class PMREMGenerator {
 	 * @param {number} [far=100] - The far plane distance.
 	 * @param {Object} [options={}] - The configuration options.
 	 * @param {number} [options.size=256] - The texture size of the PMREM.
-	 * @param {Vector3} [options.renderTarget=origin] - The position of the internal cube camera that renders the scene.
+	 * @param {Vector3} [options.position=origin] - The position of the internal cube camera that renders the scene.
 	 * @param {?RenderTarget} [options.renderTarget=null] - The render target to use.
 	 * @return {RenderTarget} The resulting PMREM.
 	 * @see {@link PMREMGenerator#fromScene}
@@ -634,7 +634,7 @@ class PMREMGenerator {
 		const incrementalRoughness = Math.sqrt( targetRoughness * targetRoughness - sourceRoughness * sourceRoughness );
 
 		// Apply blur strength mapping for better quality across the roughness range
-		const blurStrength = 0.0 + targetRoughness * 1.25;
+		const blurStrength = targetRoughness * 1.25;
 		const adjustedRoughness = incrementalRoughness * blurStrength;
 
 		// Calculate viewport position based on output LOD level