WebGLMorphtargets: Detect geometry changes.

Author: Mugen87

src/renderers/webgl/WebGLMorphtargets.js

@@ -38,22 +38,21 @@ function WebGLMorphtargets( gl, capabilities, textures ) {
 
 			// instead of using attributes, the WebGL 2 code path encodes morph targets
 			// into an array of data textures. Each layer represents a single morph target.
-			// Note: This texture is created once per geoemtry. If the set of morph targets
-			// changes over time (e.g. by adding additional morph targets), it's necessary
-			// to call dispose() on the geometry and then create a new one.
 
-			let texture = morphTextures.get( geometry );
+			const numberOfMorphTargets = geometry.morphAttributes.position.length;
 
-			if ( texture === undefined ) {
+			let entry = morphTextures.get( geometry );
+
+			if ( entry === undefined || entry.count !== numberOfMorphTargets ) {
+
+				if ( entry !== undefined ) entry.texture.dispose();
 
 				const hasMorphNormals = geometry.morphAttributes.normal !== undefined;
 
 				const morphTargets = geometry.morphAttributes.position;
 				const morphNormals = geometry.morphAttributes.normal || [];
 
-				const numberOfMorphTargets = morphTargets.length;
 				const numberOfVertices = geometry.attributes.position.count;
-
 				const numberOfVertexData = ( hasMorphNormals === true ) ? 2 : 1; // (v,n) vs. (v)
 
 				let size = Math.sqrt( numberOfVertices * numberOfVertexData );
@@ -62,7 +61,7 @@ function WebGLMorphtargets( gl, capabilities, textures ) {
 
 				const buffer = new Float32Array( size * size * 3 * numberOfMorphTargets );
 
-				texture = new DataTexture2DArray( buffer, size, size, numberOfMorphTargets );
+				const texture = new DataTexture2DArray( buffer, size, size, numberOfMorphTargets );
 				texture.format = RGBFormat;
 				texture.type = FloatType;
 
@@ -101,7 +100,12 @@ function WebGLMorphtargets( gl, capabilities, textures ) {
 
 				}
 
-				morphTextures.set( geometry, texture );
+				entry = {
+					count: numberOfMorphTargets,
+					texture: texture
+				};
+
+				morphTextures.set( geometry, entry );
 
 			}
 
@@ -120,8 +124,8 @@ function WebGLMorphtargets( gl, capabilities, textures ) {
 			program.getUniforms().setValue( gl, 'morphTargetBaseInfluence', morphBaseInfluence );
 			program.getUniforms().setValue( gl, 'morphTargetInfluences', objectInfluences );
 
-			program.getUniforms().setValue( gl, 'morphTargets', texture, textures );
-			program.getUniforms().setValue( gl, 'morphTargetsSize', texture.image.width );
+			program.getUniforms().setValue( gl, 'morphTargets', entry.texture, textures );
+			program.getUniforms().setValue( gl, 'morphTargetsSize', entry.texture.image.width );
 
 
 		} else {