fixed dielectric.glsl

Author: devshgraphicsprogramming

examples_tests/42.FragmentShaderPathTracer/common.glsl

@@ -331,12 +331,16 @@ void missProgram()
 #include <irr/builtin/glsl/bxdf/brdf/specular/beckmann.glsl>
 #include <irr/builtin/glsl/bxdf/brdf/specular/ggx.glsl>
 #include <irr/builtin/glsl/bxdf/bsdf/diffuse/lambert.glsl>
-//#include <irr/builtin/glsl/bxdf/bsdf/specular/dielectric.glsl>
+#include <irr/builtin/glsl/bxdf/bsdf/specular/dielectric.glsl>
 //#include <irr/builtin/glsl/bxdf/bsdf/specular/beckmann.glsl>
 irr_glsl_LightSample irr_glsl_bsdf_cos_generate(in irr_glsl_AnisotropicViewSurfaceInteraction interaction, in vec3 u, in BSDFNode bsdf, in float monochromeEta, out irr_glsl_AnisotropicMicrofacetCache _cache)
 {
     const float a = BSDFNode_getRoughness(bsdf);
     const mat2x3 ior = BSDFNode_getEta(bsdf);
+    
+    // fresnel stuff for dielectrics
+    float orientedEta, rcpOrientedEta;
+    const bool viewerInsideMedium = irr_glsl_getOrientedEtas(orientedEta,rcpOrientedEta,interaction.isotropic.NdotV,monochromeEta);
 
     irr_glsl_LightSample smpl;
     irr_glsl_AnisotropicMicrofacetCache dummy;
@@ -349,7 +353,7 @@ irr_glsl_LightSample irr_glsl_bsdf_cos_generate(in irr_glsl_AnisotropicViewSurfa
             smpl = irr_glsl_ggx_cos_generate(interaction,u.xy,a,a,_cache);
             break;
         default:
-            smpl = irr_glsl_beckmann_cos_generate(interaction,u.xy,a,a,_cache);
+            smpl = irr_glsl_smooth_dielectric_cos_generate(interaction,u,monochromeEta);
             //smpl = irr_glsl_beckmann_dielectric_cos_generate(interaction,u,a,a,monochromeEta,_cache);
             break;
     }
@@ -363,25 +367,25 @@ vec3 irr_glsl_bsdf_cos_remainder_and_pdf(out float pdf, in irr_glsl_LightSample
 
     // is the BSDF or BRDF, if it is then we make the dot products `abs` before `max(,0.0)`
     const bool transmissive = BSDFNode_isBSDF(bsdf);
-    
-    // obtain stuff for transmissive parts of BSDFs
-    float orientedEta, rcpOrientedEta;
-    const bool viewerInsideMedium = irr_glsl_getOrientedEtas(orientedEta,rcpOrientedEta,interaction.isotropic.NdotV,monochromeEta);
+    const float clampedNdotL = irr_glsl_conditionalAbsOrMax(transmissive,_sample.NdotL,0.0);
+    const float clampedNdotV = irr_glsl_conditionalAbsOrMax(transmissive,interaction.isotropic.NdotV,0.0);
 
     vec3 remainder;
-    if (transmissive || !transmitted)
+
+    const float minimumProjVectorLen = 0.00000001;
+    if (clampedNdotV>minimumProjVectorLen && clampedNdotL>minimumProjVectorLen)
     {
-        //
+        // fresnel stuff for conductors (but reflectance also doubles as albedo)
         const mat2x3 ior = BSDFNode_getEta(bsdf);
         const vec3 reflectance = BSDFNode_getReflectance(bsdf,_cache.isotropic.VdotH);
 
+        // fresnel stuff for dielectrics
+        float orientedEta, rcpOrientedEta;
+        const bool viewerInsideMedium = irr_glsl_getOrientedEtas(orientedEta,rcpOrientedEta,interaction.isotropic.NdotV,monochromeEta);
+
         //
         const float VdotL = dot(interaction.isotropic.V.dir,_sample.L);
 
-        // is the BSDF or BRDF, if it is then we make the dot products `abs` before `max(,0.0)`
-        const float clampedNdotL = irr_glsl_conditionalAbsOrMax(transmissive,_sample.NdotL,0.0);
-        const float clampedNdotV = irr_glsl_conditionalAbsOrMax(transmissive,interaction.isotropic.NdotV,0.0);
-
         //
         const float a = max(BSDFNode_getRoughness(bsdf),0.01); // TODO: @Crisspl 0-roughness still doesn't work! Also Beckmann has a weird dark rim instead as fresnel!?
         const float a2 = a*a;
@@ -395,8 +399,7 @@ vec3 irr_glsl_bsdf_cos_remainder_and_pdf(out float pdf, in irr_glsl_LightSample
                 remainder = irr_glsl_ggx_cos_remainder_and_pdf_wo_clamps(pdf,irr_glsl_ggx_trowbridge_reitz(a2,_cache.isotropic.NdotH2),clampedNdotL,_sample.NdotL2,clampedNdotV,interaction.isotropic.NdotV_squared,reflectance,a2);
                 break;
             default:
-                remainder = irr_glsl_beckmann_cos_remainder_and_pdf_wo_clamps(pdf,irr_glsl_beckmann(a2,_cache.isotropic.NdotH2),_sample.NdotL2,clampedNdotV,interaction.isotropic.NdotV_squared,reflectance,a2);
-                //remainder = vec3(irr_glsl_lambertian_transmitter_cos_remainder_and_pdf(pdf,_sample));
+                remainder = vec3(irr_glsl_smooth_dielectric_cos_remainder_and_pdf(pdf,_sample,interaction.isotropic,monochromeEta));
                 //remainder = vec3(irr_glsl_beckmann_dielectric_cos_remainder_and_pdf(pdf, _sample, interaction.isotropic, monochromeEta, a2));
                 break;
         }

examples_tests/42.FragmentShaderPathTracer/litBySphere.frag

@@ -172,13 +172,12 @@ void closestHitProgram(in ImmutableRay_t _immutable, inout irr_glsl_xoroshiro64s
             );
             throughput *= lightRemainder;
         }
+
+        bool validPath = true;
         const vec3 throughputCIE_Y = transpose(irr_glsl_sRGBtoXYZ)[1]*throughput;
         const float monochromeEta = dot(throughputCIE_Y,BSDFNode_getEta(bsdf)[0])/(throughputCIE_Y.r+throughputCIE_Y.g+throughputCIE_Y.b);
         if (doNEE)
-        {
-            const bool validPath = irr_glsl_calcAnisotropicMicrofacetCache(_cache,interaction,_sample,monochromeEta);
-            throughput = validPath ? throughput:vec3(0.0);
-        }
+            validPath = irr_glsl_calcAnisotropicMicrofacetCache(_cache,interaction,_sample,monochromeEta);
         else
         {
             maxT = FLT_MAX;
@@ -188,7 +187,10 @@ void closestHitProgram(in ImmutableRay_t _immutable, inout irr_glsl_xoroshiro64s
         // do a cool trick and always compute the bsdf parts this way! (no divergence)
         float bsdfPdf;
         // the value of the bsdf divided by the probability of the sample being generated
-        throughput *= irr_glsl_bsdf_cos_remainder_and_pdf(bsdfPdf,_sample,interaction,bsdf,monochromeEta,_cache);
+        if (validPath)
+            throughput *= irr_glsl_bsdf_cos_remainder_and_pdf(bsdfPdf,_sample,interaction,bsdf,monochromeEta,_cache);
+        else
+            throughput = vec3(0.0);
 
         // OETF smallest perceptible value
         const float bsdfPdfThreshold = getLuma(irr_glsl_eotf_sRGB(vec3(1.0)/255.0));

include/irr/builtin/glsl/bxdf/bsdf/specular/dielectric.glsl

@@ -2,14 +2,15 @@
 #define _IRR_BSDF_DIELECTRIC_INCLUDED_
 
 #include <irr/builtin/glsl/math/functions.glsl>
+#include <irr/builtin/glsl/bxdf/common.glsl>
 #include <irr/builtin/glsl/bxdf/common_samples.glsl>
 #include <irr/builtin/glsl/bxdf/fresnel.glsl>
 
 // usually `luminosityContributionHint` would be the Rec.709 luma coefficients (the Y row of the RGB to CIE XYZ matrix)
 // its basically a set of weights that determine 
 // assert(1.0==luminosityContributionHint.r+luminosityContributionHint.g+luminosityContributionHint.b);
 // `remainderMetadata` is a variable in which the generator function returns byproducts of sample generation that would otherwise have to be redundantly calculated in `remainder_and_pdf`
-irr_glsl_LightSample irr_glsl_thin_smooth_dielectric_cos_generate_wo_clamps(in vec3 V, in vec3 N, in float NdotV, in float absNdotV, vec3 u, in vec3 eta2, in vec3 luminosityContributionHint, out vec3 remainderMetadata)
+irr_glsl_LightSample irr_glsl_thin_smooth_dielectric_cos_generate_wo_clamps(in vec3 V, in vec3 T, in vec3 B, in vec3 N, in float NdotV, in float absNdotV, vec3 u, in vec3 eta2, in vec3 luminosityContributionHint, out vec3 remainderMetadata)
 {
     // we will only ever intersect from the outside
     const vec3 reflectance = irr_glsl_thindielectric_infinite_scatter(irr_glsl_fresnel_dielectric_common(eta2,absNdotV));
@@ -20,34 +21,22 @@ irr_glsl_LightSample irr_glsl_thin_smooth_dielectric_cos_generate_wo_clamps(in v
     float rcpChoiceProb;
     const bool transmitted = irr_glsl_partitionRandVariable(reflectionProb, u.z, rcpChoiceProb);
     remainderMetadata = (transmitted ? (vec3(1.0)-reflectance):reflectance)*rcpChoiceProb;
-
-    irr_glsl_BxDFSample smpl;
-    smpl.L = (transmitted ? vec3(0.0):N*2.0*NdotV)-V;
-    /* Undefined
-    s.TdotL = L.x;
-    s.BdotL = L.y;
-    s.NdotL = L.z;
-    s.TdotH = H.x;
-    s.BdotH = H.y;
-    s.NdotH = H.z;
-    s.VdotH = VdotH;
-    s.LdotH = LdotH;*/
-    return smpl;
+    
+    const vec3 L = (transmitted ? vec3(0.0):N*2.0*NdotV)-V;
+    return irr_glsl_createLightSample(L,dot(V,L),T,B,N);
 }
 
 
 
-irr_glsl_LightSample irr_glsl_thin_smooth_dielectric_cos_generate_wo_clamps(in vec3 V, in vec3 N, in float NdotV, in float absNdotV, vec3 u, in vec3 eta2, in vec3 luminosityContributionHint)
+irr_glsl_LightSample irr_glsl_thin_smooth_dielectric_cos_generate_wo_clamps(in vec3 V, in vec3 T, in vec3 B, in vec3 N, in float NdotV, in float absNdotV, vec3 u, in vec3 eta2, in vec3 luminosityContributionHint)
 {
     vec3 dummy;
-    irr_glsl_BxDFSample smpl = irr_glsl_thin_smooth_dielectric_cos_generate_wo_clamps(V,N,NdotV,absNdotV,u,eta2,luminosityContributionHint,dummy);
-    smpl.NdotL = dot(N,smpl.L);
-    return smpl;
+    return irr_glsl_thin_smooth_dielectric_cos_generate_wo_clamps(V,T,B,N,NdotV,absNdotV,u,eta2,luminosityContributionHint,dummy);
 }
 
 irr_glsl_LightSample irr_glsl_thin_smooth_dielectric_cos_generate(in irr_glsl_AnisotropicViewSurfaceInteraction interaction, vec3 u, in vec3 eta2, in vec3 luminosityContributionHint)
 {
-    return irr_glsl_thin_smooth_dielectric_cos_generate_wo_clamps(interaction.isotropic.V.dir,interaction.isotropic.N,interaction.isotropic.NdotV,abs(interaction.isotropic.NdotV),u,eta2,luminosityContributionHint);
+    return irr_glsl_thin_smooth_dielectric_cos_generate_wo_clamps(interaction.isotropic.V.dir,interaction.T,interaction.B,interaction.isotropic.N,interaction.isotropic.NdotV,abs(interaction.isotropic.NdotV),u,eta2,luminosityContributionHint);
 }
 
 
@@ -69,7 +58,7 @@ vec3 irr_glsl_thin_smooth_dielectric_cos_remainder_and_pdf_wo_clamps(out float p
     return irr_glsl_thin_smooth_dielectric_cos_remainder_and_pdf_wo_clamps(pdf, sampleValue / sampleProb);
 }
 
-vec3 irr_glsl_thin_smooth_dielectric_cos_remainder_and_pdf(out float pdf, in irr_glsl_BxDFSample _sample, in irr_glsl_IsotropicViewSurfaceInteraction interaction, in vec3 eta2, in vec3 luminosityContributionHint)
+vec3 irr_glsl_thin_smooth_dielectric_cos_remainder_and_pdf(out float pdf, in irr_glsl_LightSample _sample, in irr_glsl_IsotropicViewSurfaceInteraction interaction, in vec3 eta2, in vec3 luminosityContributionHint)
 {
     const bool transmitted = irr_glsl_isTransmissionPath(interaction.NdotV,_sample.NdotL);
     return irr_glsl_thin_smooth_dielectric_cos_remainder_and_pdf_wo_clamps(pdf,transmitted,abs(interaction.NdotV),eta2,luminosityContributionHint);
@@ -78,45 +67,34 @@ vec3 irr_glsl_thin_smooth_dielectric_cos_remainder_and_pdf(out float pdf, in irr
 
 
 
-irr_glsl_LightSample irr_glsl_smooth_dielectric_cos_generate_wo_clamps(in vec3 V, in vec3 N, in bool backside, in float NdotV, in float absNdotV, in float NdotV2, vec3 u, in float rcpOrientedEta, in float orientedEta2, in float rcpOrientedEta2, out bool transmitted)
+irr_glsl_LightSample irr_glsl_smooth_dielectric_cos_generate_wo_clamps(in vec3 V, in vec3 T, in vec3 B, in vec3 N, in bool backside, in float NdotV, in float absNdotV, in float NdotV2, vec3 u, in float rcpOrientedEta, in float orientedEta2, in float rcpOrientedEta2, out bool transmitted)
 {
     const float reflectance = irr_glsl_fresnel_dielectric_common(orientedEta2,absNdotV);
 
     float rcpChoiceProb;
     transmitted = irr_glsl_partitionRandVariable(reflectance, u.z, rcpChoiceProb);
 
-    irr_glsl_BxDFSample smpl;
-    smpl.L = irr_glsl_reflect_refract(transmitted, V, N, backside, NdotV, NdotV2, rcpOrientedEta, rcpOrientedEta2);
-    /* Undefined
-    s.TdotL = L.x;
-    s.BdotL = L.y;
-    s.NdotL = L.z;
-    s.TdotH = H.x;
-    s.BdotH = H.y;
-    s.NdotH = H.z;
-    s.VdotH = VdotH;*/
-    return smpl;
+    const vec3 L = irr_glsl_reflect_refract(transmitted, V, N, backside, NdotV, NdotV2, rcpOrientedEta, rcpOrientedEta2);
+    return irr_glsl_createLightSample(L,dot(V,L),T,B,N);
 }
 
-irr_glsl_BxDFSample irr_glsl_smooth_dielectric_cos_generate(in irr_glsl_AnisotropicViewSurfaceInteraction interaction, vec3 u, in float eta)
+irr_glsl_LightSample irr_glsl_smooth_dielectric_cos_generate(in irr_glsl_AnisotropicViewSurfaceInteraction interaction, vec3 u, in float eta)
 {
-    float rcpOrientedEta, orientedEta2, rcpOrientedEta2;
-    const bool backside = irr_glsl_getOrientedEtas(rcpOrientedEta, orientedEta2, rcpOrientedEta2, interaction.isotropic.NdotV, eta);
+    float orientedEta, rcpOrientedEta;
+    const bool backside = irr_glsl_getOrientedEtas(orientedEta, rcpOrientedEta, interaction.isotropic.NdotV, eta);
 
     bool dummy;
-    irr_glsl_BxDFSample smpl = irr_glsl_smooth_dielectric_cos_generate_wo_clamps(
+    return irr_glsl_smooth_dielectric_cos_generate_wo_clamps(
         interaction.isotropic.V.dir,
-        interaction.isotropic.N,
+        interaction.T,interaction.B,interaction.isotropic.N,
         backside,
         interaction.isotropic.NdotV,
         abs(interaction.isotropic.NdotV),
         interaction.isotropic.NdotV*interaction.isotropic.NdotV,
         u,
-        rcpOrientedEta, orientedEta2, rcpOrientedEta2,
+        rcpOrientedEta, orientedEta*orientedEta, rcpOrientedEta*rcpOrientedEta,
         dummy
     );
-    smpl.NdotL = dot(interaction.isotropic.N,smpl.L);
-    return smpl;
 }
 
 
@@ -126,46 +104,14 @@ float irr_glsl_smooth_dielectric_cos_remainder_and_pdf(out float pdf, in bool tr
     return transmitted ? rcpOrientedEta2:1.0;
 }
 
-float irr_glsl_smooth_dielectric_cos_remainder_and_pdf(out float pdf, in irr_glsl_BxDFSample _sample, in irr_glsl_IsotropicViewSurfaceInteraction interaction, in float eta)
+float irr_glsl_smooth_dielectric_cos_remainder_and_pdf(out float pdf, in irr_glsl_LightSample _sample, in irr_glsl_IsotropicViewSurfaceInteraction interaction, in float eta)
 {
     const bool transmitted = irr_glsl_isTransmissionPath(interaction.NdotV,_sample.NdotL);
-    float dummy0,dummy1,rcpOrientedEta2;
-    irr_glsl_getOrientedEtas(dummy0,dummy1,rcpOrientedEta2,interaction.NdotV,eta);
-    return irr_glsl_smooth_dielectric_cos_remainder_and_pdf(pdf,transmitted,rcpOrientedEta2);
-}
-
-
-
-#if 0 // TODO: Pseudo-spectral rendering.
-//this is probably wrong so not touching it
-vec3 wavelen;
-irr_glsl_BSDFSample irr_glsl_smooth_dielectric_cos_generate(in irr_glsl_AnisotropicViewSurfaceInteraction interaction, vec3 u, in vec3 eta, )
-{
-    float NdotV = interaction.isotropic.NdotV;
-    vec3 Fr = irr_glsl_fresnel_dielectric(eta, NdotV);
-    float reflectionProb = dot(vec3(1.0/3.0),Fr);//dot(Fr, luminosityContributionHint);
-
-    const bool refracted = irr_glsl_partitionRandVariable(reflectionProb, u.z, throuhgput);
-
-    float _eta = u.z < 0.5 ? mix(eta.r, eta.g, u.z * 2.0) : mix(eta.g, eta.b, u.z * 2.0 - 1.0);
-    wavelen = u.z<0.5 ? mix(vec3(4.0,0.0,0.0),vec3(0.0,2.0,0.0),u.z*2.0):mix(vec3(0.0,2.0,0.0),vec3(0.0,0.0,4.0),u.z*2.0-1.0);
-
-    irr_glsl_BSDFSample smpl;
-    smpl.L = irr_glsl_reflect_refract(refracted, interaction.isotropic.V.dir, interaction.isotropic.N, NdotV, NdotV*NdotV, _eta);
-    return smpl;
-}
+    
+    float dummy, rcpOrientedEta;
+    const bool backside = irr_glsl_getOrientedEtas(dummy, rcpOrientedEta, interaction.NdotV, eta);
 
-vec3 irr_glsl_smooth_dielectric_cos_remainder_and_pdf(out float pdf, in irr_glsl_BSDFSample _sample, in irr_glsl_IsotropicViewSurfaceInteraction interaction, in vec3 eta)
-{
-    pdf = 1.0/0.0; // should be reciprocal probability of the fresnel choice divided by 0.0, but still an INF.
-    vec3 retval = vec3(1.0);
-    return wavelen;
+    return irr_glsl_smooth_dielectric_cos_remainder_and_pdf(pdf,transmitted,rcpOrientedEta);
 }
-vec3 irr_glsl_smooth_dielectric_cos_remainder_and_pdf(out float pdf, in irr_glsl_BSDFSample _sample, in irr_glsl_IsotropicViewSurfaceInteraction interaction, in vec3 eta, in float throughput)
-{
-    return irr_glsl_smooth_dielectric_cos_remainder_and_pdf(pdf,_sample,interaction,eta);
-}
-#endif
-
 
 #endif

include/irr/builtin/glsl/bxdf/common.glsl

@@ -71,7 +71,7 @@ irr_glsl_LightSample irr_glsl_createLightSampleTangentSpace(in vec3 tangentSpace
 }
 
 //
-irr_glsl_LightSample irr_glsl_createLightSample(in vec3 L, in float VdotL, in irr_glsl_IsotropicViewSurfaceInteraction interaction)
+irr_glsl_LightSample irr_glsl_createLightSample(in vec3 L, in float VdotL, in vec3 N)
 {
     irr_glsl_LightSample s;
 
@@ -80,32 +80,32 @@ irr_glsl_LightSample irr_glsl_createLightSample(in vec3 L, in float VdotL, in ir
 
     s.TdotL = irr_glsl_FLT_NAN;
     s.BdotL = irr_glsl_FLT_NAN;
-    s.NdotL = dot(interaction.N,L);
+    s.NdotL = dot(N,L);
     s.NdotL2 = s.NdotL*s.NdotL;
 
     return s;
 }
 irr_glsl_LightSample irr_glsl_createLightSample(in vec3 L, in irr_glsl_IsotropicViewSurfaceInteraction interaction)
 {
-    return irr_glsl_createLightSample(L,dot(interaction.V.dir,L),interaction);
+    return irr_glsl_createLightSample(L,dot(interaction.V.dir,L),interaction.N);
 }
-irr_glsl_LightSample irr_glsl_createLightSample(in vec3 L, in float VdotL, in irr_glsl_AnisotropicViewSurfaceInteraction interaction)
+irr_glsl_LightSample irr_glsl_createLightSample(in vec3 L, in float VdotL, in vec3 T, in vec3 B, in vec3 N)
 {
     irr_glsl_LightSample s;
 
     s.L = L;
     s.VdotL = VdotL;
 
-    s.TdotL = dot(interaction.T,L);
-    s.BdotL = dot(interaction.B,L);
-    s.NdotL = dot(interaction.isotropic.N,L);
+    s.TdotL = dot(T,L);
+    s.BdotL = dot(B,L);
+    s.NdotL = dot(N,L);
     s.NdotL2 = s.NdotL*s.NdotL;
 
     return s;
 }
 irr_glsl_LightSample irr_glsl_createLightSample(in vec3 L, in irr_glsl_AnisotropicViewSurfaceInteraction interaction)
 {
-    return irr_glsl_createLightSample(L,dot(interaction.isotropic.V.dir,L),interaction);
+    return irr_glsl_createLightSample(L,dot(interaction.isotropic.V.dir,L),interaction.T,interaction.B,interaction.isotropic.N);
 }
 
 //TODO move to different glsl header @Crisspl (The code is not DRY, you have something similar in material compiler!)

include/irr/builtin/glsl/bxdf/common_samples.glsl

@@ -6,7 +6,7 @@
 
 irr_glsl_LightSample irr_glsl_transmission_cos_generate(in irr_glsl_AnisotropicViewSurfaceInteraction interaction)
 {
-    return irr_glsl_createLightSample(-interaction.isotropic.V.dir,-1.0,interaction);
+    return irr_glsl_createLightSample(-interaction.isotropic.V.dir,-1.0,interaction.T,interaction.B,interaction.isotropic.N);
 }
 
 float irr_glsl_transmission_cos_remainder_and_pdf(out float pdf, in irr_glsl_LightSample s)