PMREMNode: Move texture cache into class scope.

Author: Mugen87

src/nodes/pmrem/PMREMNode.js

@@ -8,8 +8,6 @@ import { nodeProxy, vec3 } from '../tsl/TSLBase.js';
 import { Texture } from '../../textures/Texture.js';
 import PMREMGenerator from '../../renderers/common/extras/PMREMGenerator.js';
 
-const _cache = new WeakMap();
-
 /**
  * Generates the cubeUV size based on the given image height.
  *
@@ -35,11 +33,12 @@ function _generateCubeUVSize( imageHeight ) {
  * @private
  * @param {Texture} texture - The texture to create the PMREM for.
  * @param {PMREMGenerator} generator - The PMREM generator.
+ * @param {WeakMap<Texture,Texture>} cache - The PMREM texture cache.
  * @return {Texture} The PMREM.
  */
-function _getPMREMFromTexture( texture, generator ) {
+function _getPMREMFromTexture( texture, generator, cache ) {
 
-	let cacheTexture = _cache.get( texture );
+	let cacheTexture = cache.get( texture );
 
 	const pmremVersion = cacheTexture !== undefined ? cacheTexture.pmremVersion : - 1;
 
@@ -76,7 +75,7 @@ function _getPMREMFromTexture( texture, generator ) {
 
 		cacheTexture.pmremVersion = texture.pmremVersion;
 
-		_cache.set( texture, cacheTexture );
+		cache.set( texture, cacheTexture );
 
 	}
 
@@ -132,14 +131,14 @@ class PMREMNode extends TempNode {
 		this._pmrem = null;
 
 		/**
-		 *  The uv node.
+		 * The uv node.
 		 *
 		 * @type {Node<vec2>}
 		 */
 		this.uvNode = uvNode;
 
 		/**
-		 *  The level node.
+		 * The level node.
 		 *
 		 * @type {Node<float>}
 		 */
@@ -189,6 +188,14 @@ class PMREMNode extends TempNode {
 		 */
 		this._maxMip = uniform( 0 );
 
+		/**
+		 * The PMREM texture cache.
+		 *
+		 * @private
+		 * @type {WeakMap<Texture,Texture>}
+		 */
+		this._cache = new WeakMap();
+
 		/**
 		 * The `updateBeforeType` is set to `NodeUpdateType.RENDER`.
 		 *
@@ -248,7 +255,7 @@ class PMREMNode extends TempNode {
 
 			} else {
 
-				pmrem = _getPMREMFromTexture( texture, this._generator );
+				pmrem = _getPMREMFromTexture( texture, this._generator, this._cache );
 
 			}