PMREMGenerator now appropriately flips cube textures from WebGLRenderTargetCube. Fixes #15301

Author: jsantell

examples/js/pmrem/PMREMGenerator.js

@@ -17,8 +17,8 @@ THREE.PMREMGenerator = function ( sourceTexture, samplesPerLevel, resolution ) {
 	this.resolution = ( resolution !== undefined ) ? resolution : 256; // NODE: 256 is currently hard coded in the glsl code for performance reasons
 	this.samplesPerLevel = ( samplesPerLevel !== undefined ) ? samplesPerLevel : 16;
 
-	var monotonicEncoding = ( sourceTexture.encoding === THREE.LinearEncoding ) ||
-		( sourceTexture.encoding === THREE.GammaEncoding ) || ( sourceTexture.encoding === THREE.sRGBEncoding );
+	var monotonicEncoding = ( this.sourceTexture.encoding === THREE.LinearEncoding ) ||
+		( this.sourceTexture.encoding === THREE.GammaEncoding ) || ( this.sourceTexture.encoding === THREE.sRGBEncoding );
 
 	this.sourceTexture.minFilter = ( monotonicEncoding ) ? THREE.LinearFilter : THREE.NearestFilter;
 	this.sourceTexture.magFilter = ( monotonicEncoding ) ? THREE.LinearFilter : THREE.NearestFilter;
@@ -84,6 +84,7 @@ THREE.PMREMGenerator.prototype = {
 	update: function ( renderer ) {
 
 		this.shader.uniforms[ 'envMap' ].value = this.sourceTexture;
+		this.shader.uniforms[ 'tFlip' ].value = ( this.sourceTexture.isCubeTexture ) ? 1 : -1;
 		this.shader.envMap = this.sourceTexture;
 
 		var gammaInput = renderer.gammaInput;
@@ -151,6 +152,7 @@ THREE.PMREMGenerator.prototype = {
 				"envMap": { value: null },
 				"queryScale": { value: new THREE.Vector3( 1, 1, 1 ) },
 				"testColor": { value: new THREE.Vector3( 1, 1, 1 ) },
+				"tFlip": { value: -1 },
 			},
 
 			vertexShader:
@@ -169,6 +171,7 @@ THREE.PMREMGenerator.prototype = {
 				uniform float mapSize;\n\
 				uniform vec3 testColor;\n\
 				uniform vec3 queryScale;\n\
+				uniform int tFlip;\n\
 				\n\
 				float GGXRoughnessToBlinnExponent( const in float ggxRoughness ) {\n\
 					float a = ggxRoughness + 0.0001;\n\
@@ -239,6 +242,7 @@ THREE.PMREMGenerator.prototype = {
 					} else {\n\
 						sampleDirection = vec3(-uv.x, -uv.y, -1.0);\n\
 					}\n\
+					sampleDirection.x *= float(tFlip);\n\
 					mat3 vecSpace = matrixFromVector(normalize(sampleDirection * queryScale));\n\
 					vec3 rgbColor = vec3(0.0);\n\
 					const int NumSamples = SAMPLES_PER_LEVEL;\n\
@@ -251,8 +255,9 @@ THREE.PMREMGenerator.prototype = {
 						vect = ImportanceSampleGGX(vec2(float(i) / float(NumSamples), r), vecSpace, roughness);\n\
 						float dotProd = dot(vect, normalize(sampleDirection));\n\
 						weight += dotProd;\n\
-						vec3 color = envMapTexelToLinear(textureCube(envMap,vect)).rgb;\n\
-						rgbColor.rgb += color;\n\
+						vec4 color = textureCube(envMap, vect.xyz);\n\
+						vec3 mapped = envMapTexelToLinear(color).rgb;\n\
+						rgbColor.rgb += mapped;\n\
 					}\n\
 					rgbColor /= float(NumSamples);\n\
 					//rgbColor = testColorMap( roughness ).rgb;\n\