Update IOR to be a mask map

6 年前 · 2ad2a458
--- a/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Material/Lit/LitUI.cs
+++ b/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Material/Lit/LitUI.cs
            public static GUIContent thicknessRemapText = new GUIContent("Thickness Remap", "Remaps values of the thickness map from [0, 1] to the specified range.");

            // Iridescence
-            public static GUIContent iorIridescenceText = new GUIContent("Iridescence IOR", "Controls the number of color fringes with increasing angle (view dependent): Smaller mean more fringe. Also modify intensity and saturation of color fringes: Higher value mean more intense and saturate.");
+            public static GUIContent iridescenceMaskText = new GUIContent("Iridescence Mask", "Control intensity of the iridescence");
            public static GUIContent thicknessIridescenceText = new GUIContent("Iridescence Thickness");
            public static GUIContent thicknessMapIridescenceText = new GUIContent("Iridescence Thickness map");
            public static GUIContent thicknessRemapIridescenceText = new GUIContent("Iridescence Thickness remap");
        protected MaterialProperty anisotropyMap = null;
        protected const string kAnisotropyMap = "_AnisotropyMap";

-        protected MaterialProperty iorIridescence = null;
-        protected const string kIorIridescence = "_IorIridescence";
+        protected MaterialProperty iridescenceMask = null;
+        protected const string kIridescenceMask = "_IridescenceMask";
+        protected MaterialProperty iridescenceMaskMap = null;
+        protected const string kIridescenceMaskMap = "_IridescenceMaskMap";
        protected MaterialProperty thicknessIridescence = null;
        protected const string kThicknessIridescence = "_ThicknessIridescence";
        protected MaterialProperty thicknessMapIridescence = null;
            anisotropyMap = FindProperty(kAnisotropyMap, props);

            // Iridescence
-            iorIridescence = FindProperty(kIorIridescence, props);
+            iridescenceMask = FindProperty(kIridescenceMask, props);
+            iridescenceMaskMap = FindProperty(kIridescenceMaskMap, props);
            thicknessIridescence = FindProperty(kThicknessIridescence, props);
            thicknessMapIridescence = FindProperty(kThicknessMapIridescence, props);
            thicknessRemapIridescence = FindProperty(kThicknessRemapIridescence, props);
        }
        protected void ShaderIridescenceInputGUI()
        {
-            m_MaterialEditor.ShaderProperty(iorIridescence, Styles.iorIridescenceText);
+            m_MaterialEditor.TexturePropertySingleLine(Styles.iridescenceMaskText, iridescenceMaskMap, iridescenceMask);

            m_MaterialEditor.TexturePropertySingleLine(Styles.thicknessMapIridescenceText, thicknessMapIridescence);
            if (thicknessMapIridescence.textureValue != null)
--- a/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/LayeredLit/LayeredLitData.hlsl
+++ b/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/LayeredLit/LayeredLitData.hlsl
    surfaceData.specularColor = float3(0.0, 0.0, 0.0);
    surfaceData.coatMask = 0.0;
    surfaceData.thicknessIridescence = 0.0;
-    surfaceData.iorIridescence = 1.0;
+    surfaceData.iridescenceMask = 0.0;

    // Transparency parameters
    // Use thickness from SSS
--- a/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.cs
+++ b/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.cs
            // Iridescence
            [SurfaceDataAttributes("Thickness of Iridescence")]
            public float thicknessIridescence;
-            [SurfaceDataAttributes("Index of refraction of Iridescence")]
-            public float iorIridescence;
+            [SurfaceDataAttributes("Iridescence Mask")]
+            public float iridescenceMask;

            // Forward property only


            // Iridescence
            public float thicknessIridescence;
-            public float iorIridescence;
+            public float iridescenceMask;

            // ClearCoat
            public float coatRoughness; // Automatically fill
--- a/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.cs.hlsl
+++ b/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.cs.hlsl
 #define DEBUGVIEW_LIT_SURFACEDATA_TANGENT (1013)
 #define DEBUGVIEW_LIT_SURFACEDATA_ANISOTROPY (1014)
 #define DEBUGVIEW_LIT_SURFACEDATA_THICKNESS_OF_IRIDESCENCE (1015)
-#define DEBUGVIEW_LIT_SURFACEDATA_INDEX_OF_REFRACTION_OF_IRIDESCENCE (1016)
+#define DEBUGVIEW_LIT_SURFACEDATA_IRIDESCENCE_MASK (1016)
 #define DEBUGVIEW_LIT_SURFACEDATA_INDEX_OF_REFRACTION (1017)
 #define DEBUGVIEW_LIT_SURFACEDATA_TRANSMITTANCE_COLOR (1018)
 #define DEBUGVIEW_LIT_SURFACEDATA_TRANSMITTANCE_ABSORPTION_DISTANCE (1019)
 #define DEBUGVIEW_LIT_BSDFDATA_ROUGHNESS_B (1046)
 #define DEBUGVIEW_LIT_BSDFDATA_ANISOTROPY (1047)
 #define DEBUGVIEW_LIT_BSDFDATA_THICKNESS_IRIDESCENCE (1048)
-#define DEBUGVIEW_LIT_BSDFDATA_IOR_IRIDESCENCE (1049)
+#define DEBUGVIEW_LIT_BSDFDATA_IRIDESCENCE_MASK (1049)
 #define DEBUGVIEW_LIT_BSDFDATA_COAT_ROUGHNESS (1050)
 #define DEBUGVIEW_LIT_BSDFDATA_IOR (1051)
 #define DEBUGVIEW_LIT_BSDFDATA_ABSORPTION_COEFFICIENT (1052)
    float3 tangentWS;
    float anisotropy;
    float thicknessIridescence;
-    float iorIridescence;
+    float iridescenceMask;
    float ior;
    float3 transmittanceColor;
    float atDistance;
    float roughnessB;
    float anisotropy;
    float thicknessIridescence;
-    float iorIridescence;
+    float iridescenceMask;
    float coatRoughness;
    float ior;
    float3 absorptionCoefficient;
        case DEBUGVIEW_LIT_SURFACEDATA_THICKNESS_OF_IRIDESCENCE:
            result = surfacedata.thicknessIridescence.xxx;
            break;
-        case DEBUGVIEW_LIT_SURFACEDATA_INDEX_OF_REFRACTION_OF_IRIDESCENCE:
-            result = surfacedata.iorIridescence.xxx;
+        case DEBUGVIEW_LIT_SURFACEDATA_IRIDESCENCE_MASK:
+            result = surfacedata.iridescenceMask.xxx;
            break;
        case DEBUGVIEW_LIT_SURFACEDATA_INDEX_OF_REFRACTION:
            result = surfacedata.ior.xxx;
        case DEBUGVIEW_LIT_BSDFDATA_THICKNESS_IRIDESCENCE:
            result = bsdfdata.thicknessIridescence.xxx;
            break;
-        case DEBUGVIEW_LIT_BSDFDATA_IOR_IRIDESCENCE:
-            result = bsdfdata.iorIridescence.xxx;
+        case DEBUGVIEW_LIT_BSDFDATA_IRIDESCENCE_MASK:
+            result = bsdfdata.iridescenceMask.xxx;
            break;
        case DEBUGVIEW_LIT_BSDFDATA_COAT_ROUGHNESS:
            result = bsdfdata.coatRoughness.xxx;
--- a/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.hlsl
+++ b/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.hlsl
    /* 19 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT | MATERIALFEATUREFLAGS_LIT_STANDARD,
    /* 20 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT | MATERIALFEATUREFLAGS_LIT_STANDARD,

-    // Standard with clear coat and Iridescence
-    /* 21 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT | MATERIALFEATUREFLAGS_LIT_STANDARD,
-    /* 22 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_AREA | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT | MATERIALFEATUREFLAGS_LIT_STANDARD,
-    /* 23 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT | MATERIALFEATUREFLAGS_LIT_STANDARD,
-    /* 24 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT | MATERIALFEATUREFLAGS_LIT_STANDARD,
-    /* 25 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_CLEAR_COAT | MATERIALFEATUREFLAGS_LIT_STANDARD,
+    // Standard with Iridescence
+    /* 21 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_STANDARD,
+    /* 22 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_AREA | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_STANDARD,
+    /* 23 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_STANDARD,
+    /* 24 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | LIGHTFEATUREFLAGS_ENV | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_STANDARD,
+    /* 25 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIALFEATUREFLAGS_LIT_IRIDESCENCE | MATERIALFEATUREFLAGS_LIT_STANDARD,

    /* 26 */ LIGHT_FEATURE_MASK_FLAGS_OPAQUE | MATERIAL_FEATURE_MASK_FLAGS, // Catch all case with MATERIAL_FEATURE_MASK_FLAGS is needed in case we disable material classification
 };
 // Iridescence
 //-----------------------------------------------------------------------------

+// Ref: https://belcour.github.io/blog/research/2017/05/01/brdf-thin-film.html
 // Evaluation XYZ sensitivity curves in Fourier space
 float3 EvalSensitivity(float opd, float shift)
 {
 float3 EvalIridescence(float eta_1, float cosTheta1, BSDFData bsdfData)
 {
    // thicknessIridescence unit is micrometer for this equation here. Mean 0.5 is 500nm.
-    float Dinc = 2.0 * bsdfData.iorIridescence * bsdfData.thicknessIridescence;
+    float Dinc = 3.0 * bsdfData.thicknessIridescence;
+
+    // Note: Unlike the code provide with the paper, here we use schlick approximation
+    // Schlick is a very poor approximation when dealing with iridescence to the Fresnel
+    // term and there is no "neutral" value in this unlike in the original paper.
+    // We use Iridescence mask here to allow to have neutral value
-    float eta_2 = lerp(eta_1, bsdfData.iorIridescence, smoothstep(0.0, 0.03, Dinc));
+    float eta2 = lerp(2.0, 1.1, bsdfData.thicknessIridescence);
+    float eta_2 = lerp(eta_1, eta2, smoothstep(0.0, 0.03, Dinc));
    // Evaluate the cosTheta on the base layer (Snell law)
    float cosTheta2 = sqrt(1.0 - Sq(eta_1 / eta_2) * (1.0 - Sq(cosTheta1)));

    bsdfData.bitangentWS = bitangentWS;
 }

-void FillMaterialIridescence(float ior, float thickness, inout BSDFData bsdfData)
+void FillMaterialIridescence(float mask, float thickness, inout BSDFData bsdfData)
-    bsdfData.iorIridescence = ior;
+    bsdfData.iridescenceMask = mask;
    bsdfData.thicknessIridescence = thickness;
 }


    if (HasFeatureFlag(surfaceData.materialFeatures, MATERIALFEATUREFLAGS_LIT_IRIDESCENCE))
    {
-        FillMaterialIridescence(surfaceData.iorIridescence, surfaceData.thicknessIridescence, bsdfData);
+        FillMaterialIridescence(surfaceData.iridescenceMask, surfaceData.thicknessIridescence, bsdfData);
    }

    if (HasFeatureFlag(surfaceData.materialFeatures, MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
    {
        materialFeatureId = GBUFFER_LIT_IRIDESCENCE;

-        // Range of IOR is 1..2.5, so remap to 0..1
-        outGBuffer2.rgb = float3(RemapIor25to01(surfaceData.iorIridescence), surfaceData.thicknessIridescence,
+        outGBuffer2.rgb = float3(surfaceData.iridescenceMask, surfaceData.thicknessIridescence,
                                 PackFloatInt8bit(surfaceData.metallic, 0, 8));
    }
    else // Standard
        FillMaterialAnisotropy(anisotropy, frame[0], frame[1], bsdfData);
    }

+    // The neutral value of iridescenceMask is 0 (handled by ZERO_INITIALIZE).
-        // Range of IOR is 1..2.5
-        FillMaterialIridescence(RemapIor01to25(inGBuffer2.r), inGBuffer2.g, bsdfData);
+        FillMaterialIridescence(inGBuffer2.r, inGBuffer2.g, bsdfData);
    }

    // The neutral value of coatMask is 0 (handled by ZERO_INITIALIZE).
    case DEBUGVIEW_LIT_SURFACEDATA_MATERIAL_FEATURES:
        result = (surfaceData.materialFeatures.xxx) / 255.0; // Aloow to read with color picker debug mode
        break;
-    case DEBUGVIEW_LIT_SURFACEDATA_INDEX_OF_REFRACTION_OF_IRIDESCENCE:
-        result = RemapIor25to01(surfaceData.iorIridescence).xxx;
-        break;
    case DEBUGVIEW_LIT_SURFACEDATA_INDEX_OF_REFRACTION:
        result = RemapIor25to01(surfaceData.ior).xxx;
        break;
    case DEBUGVIEW_LIT_BSDFDATA_MATERIAL_FEATURES:
        result = (bsdfData.materialFeatures.xxx) / 255.0; // Aloow to read with color picker debug mode
        break;
-    case DEBUGVIEW_LIT_BSDFDATA_IOR_IRIDESCENCE:
-        result = RemapIor25to01(bsdfData.iorIridescence).xxx;
-        break;
    case DEBUGVIEW_LIT_BSDFDATA_IOR:
        result = RemapIor25to01(bsdfData.ior).xxx;
        break;

    float NdotV = ClampNdotV(preLightData.NdotV);

+    // We modify the bsdfData.fresnel0 here for iridescence
    if (HasFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_LIT_IRIDESCENCE))
    {
        float viewAngle = NdotV;
            viewAngle = sqrt(1.0 + Sq(1.0 / topIor) * (Sq(dot(bsdfData.normalWS, V)) - 1.0));
        }

-        // TEMP
-        if (bsdfData.thicknessIridescence != 0.0)
+        if (bsdfData.iridescenceMask > 0.0)
-            bsdfData.fresnel0 = EvalIridescence(topIor, viewAngle, bsdfData);
+            bsdfData.fresnel0 = lerp(bsdfData.fresnel0, EvalIridescence(topIor, viewAngle, bsdfData), bsdfData.iridescenceMask);
+    // We modify the bsdfData.fresnel0 here for clearCoat
    if (HasFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
    {
        // Fresnel0 is deduced from interface between air and material (Assume to be 1.5 in Unity, or a metal).
    if (_DebugLightingMode == DEBUGLIGHTINGMODE_LUX_METER)
    {
        // Only lighting, not BSDF
-        lighting.diffuse = color * intensity * lightData.diffuseScale;;
+        lighting.diffuse = color * intensity * lightData.diffuseScale;
    }
 #endif

    if (_DebugLightingMode == DEBUGLIGHTINGMODE_LUX_METER)
    {
        // Only lighting, not BSDF
-        lighting.diffuse = color * intensity * lightData.diffuseScale;;
+        lighting.diffuse = color * intensity * lightData.diffuseScale;
    }
 #endif

--- a/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.shader
+++ b/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.shader
        _ThicknessIridescence("Thickness sridescence", Range(0.0, 1.0)) = 1.0
        _ThicknessMapIridescence("Thickness Map Iridescence", 2D) = "white" {}
        _ThicknessRemapIridescence("Thickness Remap Iridescence", Vector) = (0, 1, 0, 0)
-        _IorIridescence("Indice Of Refraction Iridescence", Range(1.0, 2.5)) = 1.0
+        _IridescenceMask("Iridescence Mask", Range(0.0, 1.0)) = 1.0
+        _IridescenceMaskMap("Iridescence Mask Map", 2D) = "white" {}

        _CoatMask("Coat Mask", Range(0.0, 1.0)) = 0.0
        _CoatMaskMap("CoatMaskMap", 2D) = "white" {}
--- a/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitDataIndividualLayer.hlsl
+++ b/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitDataIndividualLayer.hlsl

 #ifdef _MATERIAL_FEATURE_IRIDESCENCE
    #ifdef _THICKNESSMAP_IRIDESCENCE
-    surfaceData.thicknessIridescence = SAMPLE_UVMAPPING_TEXTURE2D(_ThicknessMapIridescence, sampler_ThicknessMapIridescence, ADD_IDX(layerTexCoord.base)).r;
-    surfaceData.thicknessIridescence = ADD_IDX(_ThicknessRemapIridescence).x + ADD_IDX(_ThicknessRemapIridescence).y * surfaceData.thicknessIridescence;
+    surfaceData.thicknessIridescence = SAMPLE_UVMAPPING_TEXTURE2D(_ThicknessMapIridescence, sampler_ThicknessMapIridescence, layerTexCoord.base).r;
+    surfaceData.thicknessIridescence = _ThicknessRemapIridescence.x + _ThicknessRemapIridescence.y * surfaceData.thicknessIridescence;
-    surfaceData.thicknessIridescence = ADD_IDX(_ThicknessIridescence);
+    surfaceData.thicknessIridescence = _ThicknessIridescence;
-    surfaceData.iorIridescence = ADD_IDX(_IorIridescence);
+    surfaceData.iridescenceMask = _IridescenceMask;
+    surfaceData.iridescenceMask *= SAMPLE_UVMAPPING_TEXTURE2D(_IridescenceMaskMap, sampler_IridescenceMaskMap, layerTexCoord.base).r;
-    surfaceData.iorIridescence = 1.0;
+    surfaceData.iridescenceMask = 0.0;
 #endif

 #else // #if !defined(LAYERED_LIT_SHADER)
    surfaceData.anisotropy = 0.0;
    surfaceData.specularColor = float3(0.0, 0.0, 0.0);
    surfaceData.thicknessIridescence = 0.0;
-    surfaceData.iorIridescence = 0.0;
+    surfaceData.iridescenceMask = 0.0;
    surfaceData.coatMask = 0.0;

    // Transparency
--- a/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitProperties.hlsl
+++ b/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitProperties.hlsl
 TEXTURE2D(_ThicknessMapIridescence);
 SAMPLER(sampler_ThicknessMapIridescence);

+TEXTURE2D(_IridescenceMaskMap);
+SAMPLER(sampler_IridescenceMaskMap);
+
 TEXTURE2D(_SpecularColorMap);
 SAMPLER(sampler_SpecularColorMap);


 float _ThicknessIridescence;
 float4 _ThicknessRemapIridescence;
-float _IorIridescence;
+float _IridescenceMask;

 float _CoatMask;

--- a/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitTessellation.shader
+++ b/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitTessellation.shader
        _ThicknessIridescence("Thickness sridescence", Range(0.0, 1.0)) = 1.0
        _ThicknessMapIridescence("Thickness Map Iridescence", 2D) = "white" {}
        _ThicknessRemapIridescence("Thickness Remap Iridescence", Vector) = (0, 1, 0, 0)
-        _IorIridescence("Indice Of Refraction Iridescence", Range(1.0, 2.5)) = 1.0
+        _IridescenceMask("Iridescence Mask", Range(0.0, 1.0)) = 1.0
+        _IridescenceMaskMap("Iridescence Mask Map", 2D) = "white" {}
+

        _CoatMask("Coat Mask", Range(0.0, 1.0)) = 0.0
        _CoatMaskMap("CoatMaskMap", 2D) = "white" {}