HYDRA-1329 : Support dome lights in the custom GLSL shader

lib/flowViewport/usdPlugins/shadersDiscoveryPlugin/shaders/customBasicLightingShader.glslfx

@@ -70,6 +70,111 @@ BasicLightingCoeffs computeLightingCoefficients(vec3 L, vec3 N, vec3 V, float ex
     return coeffs;
 }
 
+//To support dome lights
+struct LightingContributions
+{
+    vec3 diffuse;
+    vec3 specular;
+};
+
+mat4 GetDomeLightTransform(mat4 worldToLightTransform)
+{
+    // transform from view space to light space
+    mat4 worldToViewInverse = GetWorldToViewInverseMatrix();
+    return worldToLightTransform * worldToViewInverse;
+}
+
+#define PI 3.1415
+vec2 ProjectToLatLong(vec3 sample3D)
+{
+    // project spherical coord onto latitude-longitude map with
+    // latitude: +y == pi/2 and longitude: +z == 0, +x == pi/2
+    float x = (atan(sample3D.z, sample3D.x) + 0.5 * PI) / (2.0 * PI);
+    float y = acos(sample3D.y) / PI;
+
+    return vec2(x,y);
+}
+
+LightingContributions
+evaluateIndirectLighting(
+        vec3 diffuseColor,
+        vec3 specularColor,
+        vec3 Neye,
+        vec3 Reye,
+        float NdotE,
+        float EdotH,
+        float ior,
+        float metallic,
+        float occlusion,
+        float roughness,
+        bool useSpecularWorkflow,
+        float clearcoatAmount, 
+        vec3 clearcoatColor, 
+        float clearcoatRoughness,
+        mat4 worldToLightTransform)
+{
+    LightingContributions indirect;
+    indirect.diffuse = vec3(0.0);
+    indirect.specular = vec3(0.0);
+
+#ifdef HD_HAS_domeLightIrradiance
+    vec3 F0 = specularColor;
+    vec3 F90 = vec3(1.0);
+    vec3 d = diffuseColor;
+    const float R = (1.0 - ior) / (1.0 + ior);
+    if (!useSpecularWorkflow) {
+        vec3 specColor = mix(vec3(1.0), diffuseColor, metallic);
+        F0 = mix(R * R * specColor, specColor, metallic);
+        F90 = specColor;
+
+        // For metallic workflows, pure metals have no diffuse
+        d *= 1.0 - metallic;
+    }
+    // Adjust the diffuse so glazing angles have less diffuse
+    float fresnel = pow(max(0.0, 1.0 - EdotH), 5.0);//SchlickFresnel
+    vec3 F = mix(F0, F90, fresnel);
+    d *= (1.0 - F);
+
+    mat4 transformationMatrix = GetDomeLightTransform(worldToLightTransform);
+
+    // Diffuse Component
+    vec3 dir = normalize((transformationMatrix * vec4(Neye,0.0)).xyz);
+    vec2 coord = ProjectToLatLong(dir);
+    vec3 diffuse = HdGet_domeLightIrradiance(coord).rgb;
+
+    // Specular Component 
+    const float MAX_REFLECTION_LOD = 
+        textureQueryLevels(HdGetSampler_domeLightPrefilter());
+    float lod = roughness * MAX_REFLECTION_LOD;
+    vec3 Rdir = normalize((transformationMatrix * vec4(Reye,0.0)).xyz);
+    vec2 Rcoord = ProjectToLatLong(Rdir);
+    vec3 prefilter = HdTextureLod_domeLightPrefilter(Rcoord, lod).rgb;
+
+    vec2 brdf = HdGet_domeLightBRDF(vec2(NdotE, roughness)).rg;
+
+    vec3 specular = prefilter * (F * brdf.x + brdf.y);
+
+    // Clearcoat Component
+    vec3 clearcoat = vec3(0.0);
+    if (clearcoatAmount > 0.0) {
+        const vec3 clearcoatF = clearcoatAmount * mix(
+            R * R * clearcoatColor, // Clearcoat F0
+            clearcoatColor,         // Clearcoat F90
+            fresnel);
+        lod = clearcoatRoughness * MAX_REFLECTION_LOD;
+        prefilter = HdTextureLod_domeLightPrefilter(Rcoord, lod).rgb;
+        clearcoat = prefilter * (clearcoatF * brdf.x + brdf.y);
+    }
+
+    // Indirect Lighting
+    indirect.diffuse = (d * diffuse) * occlusion;
+    indirect.specular = (specular + clearcoat) * occlusion;
+
+#endif
+
+    return indirect;
+}
+
 vec4
 surfaceShader(vec4 Peye, vec3 Neye, vec4 color, vec4 patchCoord)
 {
@@ -89,34 +194,65 @@ surfaceShader(vec4 Peye, vec3 Neye, vec4 color, vec4 patchCoord)
 
     vec3 n = Neye;
     vec3 e = normalize(-Peye.xyz);
+
     vec3 directLight = vec3(0.0);
+	vec3 indirectLight = vec3(0.0);//For dome light
     float glossiness = 30.0;//Hardcoded
+	float ior = 1.5; //Hardcoded
+	float metallic = 0.0;//Hardcoded
+	float occlusion = 1.0;//Hardcoded
+	bool useSpecularWorkflow = true;//Hardcoded
+	float clearcoatAmount = 0.0;//Hardcoded
+	vec3 clearcoatColor = vec3(1.0);//Hardcoded
+	float clearcoatRoughness = 0.01;//Hardcoded
 
-    //Do basic lighting
+    //Do lighting (with no shadows)
 #if NUM_LIGHTS > 0
     for (int i = 0; i < NUM_LIGHTS; ++i)
     {
-        LightSource light = GetLightSource(i);
-        if (!light.isIndirectLight)
-        {
-            vec4 Plight = light.position;
-            vec3 l = (Plight.w == 0.0)
-                        ? normalize(Plight.xyz)
-                        : normalize(Plight - Peye).xyz;
+	    LightSource light = GetLightSource(i);
+        vec4 Plight = light.isIndirectLight //light.isIndirectLight is true for dome light.
+                        ? vec4(0,0,0,1)
+                        : light.position;
+
+		vec3 l = (Plight.w == 0.0)
+					? normalize(Plight.xyz)
+					: normalize(Plight - Peye).xyz;
 
-            float atten = lightDistanceAttenuation(Peye, i);
-            float spot = lightSpotAttenuation(l, i);
+		float atten = lightDistanceAttenuation(Peye, i);
+		float spot = lightSpotAttenuation(l, i);
 
-            float intensity = 1.0 * atten * spot;
+		float intensity = 1.0 * atten * spot;
 
-            vec3 lightDiffuseIrradiance = intensity * light.diffuse.rgb;
-            vec3 lightSpecularIrradiance = intensity * light.specular.rgb;
+		vec3 lightDiffuseIrradiance = intensity * light.diffuse.rgb;
+		vec3 lightSpecularIrradiance = intensity * light.specular.rgb;
 
-            BasicLightingCoeffs coeffs = computeLightingCoefficients(l, n, e, glossiness);
-            directLight += (light.ambient.rgb *ambientColor + lightDiffuseIrradiance * coeffs.diffuse * diffuseColor + lightSpecularIrradiance * coeffs.specular * specularColor);
+		BasicLightingCoeffs coeffs = computeLightingCoefficients(l, n, e, glossiness);
+
+        if (light.isIndirectLight) {
+			float NdotE = max(0.0, dot(n, e));
+			vec3 Reye = reflect(-e, n);
+
+			vec3 h = normalize(e + l);
+			float NdotL = max(0.0, dot(n, l));
+			float NdotH = max(0.0, dot(n, h));
+			float EdotH = max(0.0, dot(e, h));
+			// Calculate the indirect light (DomeLight)
+            LightingContributions indirectLightContrib = 
+                evaluateIndirectLighting(diffuseColor, specularColor,
+                    Neye, Reye, NdotE, EdotH, ior, metallic, occlusion,
+                    glossiness, useSpecularWorkflow,
+                    clearcoatAmount, clearcoatColor, clearcoatRoughness,
+                    light.worldToLightTransform);
+            indirectLight += (indirectLightContrib.diffuse * light.diffuse.rgb 
+                           + indirectLightContrib.specular * light.specular.rgb);
         }
+        else {
+			// All other light sources contribute to the direct lighting
+			directLight += (light.ambient.rgb *ambientColor + lightDiffuseIrradiance * coeffs.diffuse * diffuseColor + lightSpecularIrradiance * coeffs.specular * specularColor);
+		}
     }
 #endif
 
-    return vec4(directLight, 1.0);
+    return vec4(directLight+indirectLight, 1.0);
 }

test/lib/mayaUsd/render/mayaToHydra/testCustomShadersNode.py

@@ -33,7 +33,15 @@ def test_LoadCustomShaderNode(self):
                 "testCustomShadersNode",
                 "testCustomShadersNode.ma")
             cmds.refresh()
-            self.assertSnapshotClose("testCustomShadersNode.png", self.IMAGE_DIFF_FAIL_THRESHOLD, self.IMAGE_DIFF_FAIL_PERCENT)
+            self.assertSnapshotClose("testCustomShadersNodeDefaultLight.png", self.IMAGE_DIFF_FAIL_THRESHOLD, self.IMAGE_DIFF_FAIL_PERCENT)
+
+            # Switch the lighting mode to use all scene lights.
+            cmds.modelEditor(mayaUtils.activeModelPanel(), edit=True, displayLights = 'all')
+            self.assertSnapshotClose("testCustomShadersNodeUseAllLights.png", self.IMAGE_DIFF_FAIL_THRESHOLD, self.IMAGE_DIFF_FAIL_PERCENT)
+
+            #Remove the direct lighting to check if the dome light works fine
+            cmds.setAttr("pointLightShape1.intensity", 0);
+            self.assertSnapshotClose("testCustomShadersNodeDomeLightOnly.png", self.IMAGE_DIFF_FAIL_THRESHOLD, self.IMAGE_DIFF_FAIL_PERCENT)
 
 if __name__ == '__main__':
     fixturesUtils.runTests(globals())

test/testSamples/testCustomShadersNode/testCustomShadersNode.ma

@@ -1,26 +1,28 @@
-//Maya ASCII 2025ff01 scene
+//Maya ASCII 2025ff02 scene
 //Name: testCustomShadersNode.ma
-//Last modified: Tue, Dec 10, 2024 02:09:44 PM
+//Last modified: Wed, Dec 11, 2024 11:46:10 AM
 //Codeset: 1252
-requires maya "2025ff01";
+requires maya "2025ff02";
 requires -nodeType "MhCustomShaders" "mayaHydraCustomShadersNode" "2025.0";
+requires -nodeType "aiOptions" -nodeType "aiAOVDriver" -nodeType "aiAOVFilter" -nodeType "aiSkyDomeLight"
+		 -nodeType "aiImagerDenoiserOidn" "mtoa" "5.5.0";
 currentUnit -l centimeter -a degree -t film;
 fileInfo "application" "maya";
 fileInfo "product" "Maya 2025";
 fileInfo "version" "Preview Release";
-fileInfo "cutIdentifier" "202406201527-000000";
+fileInfo "cutIdentifier" "202412031025-000000";
 fileInfo "osv" "Windows 10 Enterprise v2009 (Build: 19045)";
-fileInfo "UUID" "1CC4C576-45C2-C419-BB7C-C6ADB74EB77E";
+fileInfo "UUID" "32399C4F-4798-7197-6C92-ABA4785D13A3";
 createNode transform -s -n "persp";
 	rename -uid "CAC40983-46C8-183E-1AFA-C889DB90A237";
 	setAttr ".v" no;
-	setAttr ".t" -type "double3" 1.7032043776282506 1.3442620959436657 1.6628472799166649 ;
-	setAttr ".r" -type "double3" -32.738352729575475 44.999999999961283 -2.2489917831959524e-15 ;
+	setAttr ".t" -type "double3" 2.3444946207989208 2.6275868051098961 2.2417681041490223 ;
+	setAttr ".r" -type "double3" -41.138352729575864 45.799999999961258 -6.8431882242206845e-15 ;
 createNode camera -s -n "perspShape" -p "persp";
 	rename -uid "98B104E6-4BBD-86B0-9523-75B2BDF52ADE";
 	setAttr -k off ".v" no;
 	setAttr ".fl" 34.999999999999993;
-	setAttr ".coi" 2.7290490368539975;
+	setAttr ".coi" 4.1940870213230212;
 	setAttr ".imn" -type "string" "persp";
 	setAttr ".den" -type "string" "persp_depth";
 	setAttr ".man" -type "string" "persp_mask";
@@ -78,21 +80,33 @@ createNode MhCustomShaders -n "MhCustomShaders1" -p "transform1";
 	rename -uid "2588465F-4F45-D5D0-30EE-079DD68236D8";
 	setAttr -k off ".v";
 	setAttr ".col" -type "double3" 1 1 1 ;
+createNode transform -n "aiSkyDomeLight1";
+	rename -uid "C5F4165C-4AFD-9433-9888-2892633BBCC7";
+createNode aiSkyDomeLight -n "aiSkyDomeLightShape1" -p "aiSkyDomeLight1";
+	rename -uid "AA09D07E-4E4A-B07D-8CEA-5AA70457B47E";
+	setAttr -k off ".v";
+createNode transform -n "pointLight1";
+	rename -uid "5AB2DCD7-4F0C-4E42-65A9-E5824FC99182";
+	setAttr ".t" -type "double3" 0.72655050063505378 0.58409642784605986 0 ;
+createNode pointLight -n "pointLightShape1" -p "pointLight1";
+	rename -uid "61F387C9-49DA-1D37-7F8F-1D80492D0949";
+	setAttr -k off ".v";
+	setAttr ".us" no;
 createNode lightLinker -s -n "lightLinker1";
-	rename -uid "17FE1D90-4E82-91F9-865C-769041D175BC";
+	rename -uid "F9AF3BD0-44AF-9D2E-5E78-A7A859E122BC";
 	setAttr -s 2 ".lnk";
 	setAttr -s 2 ".slnk";
 createNode shapeEditorManager -n "shapeEditorManager";
-	rename -uid "8DB5C160-420F-D5BA-683B-0A89E4280978";
+	rename -uid "08EEB963-4DEE-1A77-BA04-5FBBAEBDBDED";
 createNode poseInterpolatorManager -n "poseInterpolatorManager";
-	rename -uid "D74D9600-4F8B-9358-8CF2-2DBF7BD24F2C";
+	rename -uid "3DD30F0A-4745-FDB2-C2AA-1C90F62D90E8";
 createNode displayLayerManager -n "layerManager";
-	rename -uid "B164B0DD-4EF2-18A1-6FE0-CFBF493D8E6D";
+	rename -uid "58745776-4014-38C3-8FAC-AB9D4C406B48";
 createNode displayLayer -n "defaultLayer";
 	rename -uid "E6921E06-44BE-9413-CEDF-B8BE8AAC03F8";
 	setAttr ".ufem" -type "stringArray" 0  ;
 createNode renderLayerManager -n "renderLayerManager";
-	rename -uid "AA6B9068-483F-5E56-A11F-519EA23FC0CD";
+	rename -uid "3B89CDF4-4990-B59E-02ED-CB97E5291EDE";
 createNode renderLayer -n "defaultRenderLayer";
 	rename -uid "DD7E50CB-4068-BEFD-F909-1092A320CBAA";
 	setAttr ".g" yes;
@@ -144,6 +158,25 @@ createNode script -n "sceneConfigurationScriptNode";
 	rename -uid "6D6880C9-4A2E-EBCD-99E5-47A4F9F4379A";
 	setAttr ".b" -type "string" "playbackOptions -min 1 -max 120 -ast 1 -aet 200 ";
 	setAttr ".st" 6;
+createNode aiOptions -s -n "defaultArnoldRenderOptions";
+	rename -uid "897C0433-427B-A1A7-56FF-7180E45E9460";
+	setAttr ".version" -type "string" "5.5.0";
+createNode aiAOVFilter -s -n "defaultArnoldFilter";
+	rename -uid "939FC437-435A-5D2D-E989-F6B44FC6D83B";
+createNode aiAOVDriver -s -n "defaultArnoldDriver";
+	rename -uid "FFF5C067-4E9D-AF13-BE0A-57BE613433BF";
+createNode aiAOVDriver -s -n "defaultArnoldDisplayDriver";
+	rename -uid "FAA3D8DB-498D-8F49-E692-9AB5EA825653";
+	setAttr ".ai_translator" -type "string" "maya";
+	setAttr ".output_mode" 0;
+createNode aiImagerDenoiserOidn -s -n "defaultArnoldDenoiser";
+	rename -uid "58A6D5FC-429A-C8A7-38B0-92BE87D40FF7";
+createNode file -n "file1";
+	rename -uid "73223ABC-4CB5-EDF7-2134-1ABC6D855D11";
+	setAttr ".ftn" -type "string" "D:/GIT/maya-hydra-opensource/test/testSamples/testCustomShadersNode/UVChecker.png";
+	setAttr ".cs" -type "string" "sRGB";
+createNode place2dTexture -n "place2dTexture1";
+	rename -uid "1C593DED-4767-D011-1183-BD90C0A7794B";
 select -ne :time1;
 	setAttr ".o" 1;
 	setAttr ".unw" 1;
@@ -161,7 +194,11 @@ select -ne :defaultShaderList1;
 	setAttr -s 6 ".s";
 select -ne :postProcessList1;
 	setAttr -s 2 ".p";
+select -ne :defaultRenderUtilityList1;
 select -ne :defaultRenderingList1;
+select -ne :lightList1;
+	setAttr -s 2 ".l";
+select -ne :defaultTextureList1;
 select -ne :standardSurface1;
 	setAttr ".bc" -type "float3" 0.40000001 0.40000001 0.40000001 ;
 	setAttr ".sr" 0.5;
@@ -203,6 +240,8 @@ select -ne :defaultRenderGlobals;
 	setAttr ".dss" -type "string" "standardSurface1";
 select -ne :defaultResolution;
 	setAttr ".pa" 1;
+select -ne :defaultLightSet;
+	setAttr -s 2 ".dsm";
 select -ne :defaultColorMgtGlobals;
 	setAttr ".cfe" yes;
 	setAttr ".cfp" -type "string" "<MAYA_RESOURCES>/OCIO-configs/Maya2022-default/config.ocio";
@@ -215,11 +254,46 @@ select -ne :defaultColorMgtGlobals;
 select -ne :hardwareRenderGlobals;
 	setAttr ".ctrs" 256;
 	setAttr ".btrs" 512;
+connectAttr "file1.oc" "aiSkyDomeLightShape1.sc";
 relationship "link" ":lightLinker1" ":initialShadingGroup.message" ":defaultLightSet.message";
 relationship "link" ":lightLinker1" ":initialParticleSE.message" ":defaultLightSet.message";
 relationship "shadowLink" ":lightLinker1" ":initialShadingGroup.message" ":defaultLightSet.message";
 relationship "shadowLink" ":lightLinker1" ":initialParticleSE.message" ":defaultLightSet.message";
 connectAttr "layerManager.dli[0]" "defaultLayer.id";
 connectAttr "renderLayerManager.rlmi[0]" "defaultRenderLayer.rlid";
+connectAttr ":defaultArnoldDenoiser.msg" ":defaultArnoldRenderOptions.imagers" -na
+		;
+connectAttr ":defaultArnoldDisplayDriver.msg" ":defaultArnoldRenderOptions.drivers"
+		 -na;
+connectAttr ":defaultArnoldFilter.msg" ":defaultArnoldRenderOptions.filt";
+connectAttr ":defaultArnoldDriver.msg" ":defaultArnoldRenderOptions.drvr";
+connectAttr ":defaultColorMgtGlobals.cme" "file1.cme";
+connectAttr ":defaultColorMgtGlobals.cfe" "file1.cmcf";
+connectAttr ":defaultColorMgtGlobals.cfp" "file1.cmcp";
+connectAttr ":defaultColorMgtGlobals.wsn" "file1.ws";
+connectAttr "place2dTexture1.c" "file1.c";
+connectAttr "place2dTexture1.tf" "file1.tf";
+connectAttr "place2dTexture1.rf" "file1.rf";
+connectAttr "place2dTexture1.mu" "file1.mu";
+connectAttr "place2dTexture1.mv" "file1.mv";
+connectAttr "place2dTexture1.s" "file1.s";
+connectAttr "place2dTexture1.wu" "file1.wu";
+connectAttr "place2dTexture1.wv" "file1.wv";
+connectAttr "place2dTexture1.re" "file1.re";
+connectAttr "place2dTexture1.of" "file1.of";
+connectAttr "place2dTexture1.r" "file1.ro";
+connectAttr "place2dTexture1.n" "file1.n";
+connectAttr "place2dTexture1.vt1" "file1.vt1";
+connectAttr "place2dTexture1.vt2" "file1.vt2";
+connectAttr "place2dTexture1.vt3" "file1.vt3";
+connectAttr "place2dTexture1.vc1" "file1.vc1";
+connectAttr "place2dTexture1.o" "file1.uv";
+connectAttr "place2dTexture1.ofs" "file1.fs";
+connectAttr "place2dTexture1.msg" ":defaultRenderUtilityList1.u" -na;
 connectAttr "defaultRenderLayer.msg" ":defaultRenderingList1.r" -na;
+connectAttr "aiSkyDomeLightShape1.ltd" ":lightList1.l" -na;
+connectAttr "pointLightShape1.ltd" ":lightList1.l" -na;
+connectAttr "file1.msg" ":defaultTextureList1.tx" -na;
+connectAttr "aiSkyDomeLight1.iog" ":defaultLightSet.dsm" -na;
+connectAttr "pointLight1.iog" ":defaultLightSet.dsm" -na;
 // End of testCustomShadersNode.ma