fix bugs

Author: devshgraphicsprogramming

include/irr/builtin/glsl/bxdf/brdf/specular/blinn_phong.glsl

@@ -60,27 +60,23 @@ vec3 irr_glsl_blinn_phong_conductor_cos_remainder_and_pdf(out float pdf, in irr_
 }
 */
 
-float irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(in float NdotH, in float maxNdotV, in float NdotV_squared, in float NdotL2, in float n, in float a2)
+float irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(in float NdotH, in float NdotV_squared, in float NdotL2, in float n, in float a2)
 {
-    float d = irr_glsl_blinn_phong(NdotH, n);
-    float scalar_part = d/(4.0*maxNdotV);
+    float NG = irr_glsl_blinn_phong(NdotH, n);
     if (a2>FLT_MIN)
-    {
-        float g = irr_glsl_beckmann_smith_correlated(NdotV_squared, NdotL2, a2);
-        scalar_part *= g;
-    }
+        NG *= irr_glsl_beckmann_smith_correlated(NdotV_squared, NdotL2, a2);
     return scalar_part;
 }
-float irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(in float NdotH, in float maxNdotV, in float NdotV_squared, in float NdotL2, in float n)
+float irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(in float NdotH, in float NdotV_squared, in float NdotL2, in float n)
 {
     float a2 = irr_glsl_phong_exp_to_alpha2(n);
-    return irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(NdotH, maxNdotV, NdotV_squared, NdotL2, n, a2);
+    return irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(NdotH, NdotV_squared, NdotL2, n, a2);
 }
 
 vec3 irr_glsl_blinn_phong_cos_eval_wo_clamps(in float NdotH, in float maxNdotV, in float NdotV_squared, in float NdotL2, in float VdotH, in float n, in mat2x3 ior, in float a2)
 {
-    float scalar_part = irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(NdotH, maxNdotV, NdotV_squared, NdotL2, n, a2);
-    return scalar_part*irr_glsl_fresnel_conductor(ior[0], ior[1], VdotH);
+    float scalar_part = irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(NdotH, NdotV_squared, NdotL2, n, a2);
+    return irr_glsl_fresnel_conductor(ior[0], ior[1], VdotH)*irr_glsl_microfacet_to_light_measure_transform(scalar_part,maxNdotV);
 }
 vec3 irr_glsl_blinn_phong_cos_eval_wo_clamps(in float NdotH, in float maxNdotV, in float NdotV_squared, in float NdotL2, in float VdotH, in float n, in mat2x3 ior)
 {
@@ -96,31 +92,26 @@ vec3 irr_glsl_blinn_phong_cos_eval(in irr_glsl_LightSample _sample, in irr_glsl_
 }
 
 
-float irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(in float NdotH, in float NdotH2, in float TdotH2, in float BdotH2, float TdotL2, float BdotL2, in float maxNdotV, in float TdotV2, in float BdotV2, in float NdotV_squared, in float NdotL2, in float nx, in float ny, in float ax2, in float ay2)
+float irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(in float NdotH, in float NdotH2, in float TdotH2, in float BdotH2, float TdotL2, float BdotL2, in float TdotV2, in float BdotV2, in float NdotV_squared, in float NdotL2, in float nx, in float ny, in float ax2, in float ay2)
 {
     float d = irr_glsl_blinn_phong(NdotH, 1.0/(1.0-NdotH2), TdotH2, BdotH2, nx, ny);
-    float scalar_part = d/(4.0*maxNdotV);
     if (ax2>FLT_MIN || ay2>FLT_MIN)
-    {
-        float g = irr_glsl_beckmann_smith_correlated(TdotV2, BdotV2, NdotV_squared, TdotL2, BdotL2, NdotL2, ax2, ay2);
-        scalar_part *= g;
-    }
-
+        NG *= irr_glsl_beckmann_smith_correlated(TdotV2, BdotV2, NdotV_squared, TdotL2, BdotL2, NdotL2, ax2, ay2);
     return scalar_part;
 }
-float irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(in float NdotH, in float NdotH2, in float TdotH2, in float BdotH2, in float TdotL2, in float BdotL2, in float maxNdotV, in float TdotV2, in float BdotV2, in float NdotV_squared, in float NdotL2, in float nx, in float ny)
+float irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(in float NdotH, in float NdotH2, in float TdotH2, in float BdotH2, in float TdotL2, in float BdotL2, in float TdotV2, in float BdotV2, in float NdotV_squared, in float NdotL2, in float nx, in float ny)
 {
     float ax2 = irr_glsl_phong_exp_to_alpha2(nx);
     float ay2 = irr_glsl_phong_exp_to_alpha2(ny);
 
-    return irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(NdotH, NdotH2, TdotH2, BdotH2, TdotL2, BdotL2, maxNdotV, TdotV2, BdotV2, NdotV_squared, NdotL2, nx, ny, ax2, ay2);
+    return irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(NdotH, NdotH2, TdotH2, BdotH2, TdotL2, BdotL2, TdotV2, BdotV2, NdotV_squared, NdotL2, nx, ny, ax2, ay2);
 }
 
 vec3 irr_glsl_blinn_phong_cos_eval_wo_clamps(in float NdotH, in float NdotH2, in float TdotH2, in float BdotH2, in float TdotL2, in float BdotL2, in float maxNdotV, in float TdotV2, in float BdotV2, in float NdotV_squared, in float NdotL2, in float VdotH, in float nx, in float ny, in mat2x3 ior, in float ax2, in float ay2)
 {
     float scalar_part = irr_glsl_blinn_phong_cos_eval_DG_wo_clamps(NdotH, NdotH2, TdotH2, BdotH2, TdotL2, BdotL2, maxNdotV, TdotV2, BdotV2, NdotV_squared, NdotL2, nx, ny, ax2, ay2);
 
-    return scalar_part*irr_glsl_fresnel_conductor(ior[0], ior[1], VdotH);
+    return irr_glsl_fresnel_conductor(ior[0], ior[1], VdotH)*irr_glsl_microfacet_to_light_measure_transform(scalar_part,maxNdotV);
 }
 vec3 irr_glsl_blinn_phong_cos_eval_wo_clamps(in float NdotH, in float NdotH2, in float TdotH2, in float BdotH2, in float TdotL2, in float BdotL2, in float maxNdotV, in float TdotV2, in float BdotV2, in float NdotV_squared, in float NdotL2, in float VdotH, in float nx, in float ny, in mat2x3 ior)
 {

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

@@ -77,29 +77,42 @@ vec3 irr_glsl_ggx_height_correlated_cos_eval(in irr_glsl_LightSample _sample, in
 
 
 
-// TODO: unifty the two following functions into `irr_glsl_microfacet_BRDF_cos_generate_wo_clamps(vec3 H,...)` and `irr_glsl_microfacet_BRDF_cos_generate` or at least a auto declaration macro in lieu of a template
-irr_glsl_LightSample irr_glsl_ggx_cos_generate_wo_clamps(in vec3 localV, in mat3 m, in vec2 u, in float _ax, in float _ay, out irr_glsl_AnisotropicMicrofacetCache _cache)
+// TODO: unifty the two following functions into `irr_glsl_microfacet_BSDF_cos_generate_wo_clamps(vec3 H,...)` and `irr_glsl_microfacet_BSDF_cos_generate` or at least a auto declaration macro in lieu of a template
+irr_glsl_LightSample irr_glsl_ggx_dielectric_cos_generate_wo_clamps(in vec3 localV, in bool backside, in vec3 upperHemisphereLocalV, in mat3 m, in vec3 u, in float _ax, in float _ay, in float rcpOrientedEta, in float orientedEta2, in float rcpOrientedEta2, out irr_glsl_AnisotropicMicrofacetCache _cache)
 {
-    const vec3 H = irr_glsl_ggx_cos_generate(localV,u,_ax,_ay);
+    // thanks to this manouvre the H will always be in the upper hemisphere (NdotH>0.0)
+    const vec3 H = irr_glsl_ggx_cos_generate(upperHemisphereLocalV,u.xy,_ax,_ay);
+
+    const float VdotH = dot(localV, H);
+    const float reflectance = irr_glsl_fresnel_dielectric_common(orientedEta2, abs(VdotH));
+    
+    float rcpChoiceProb;
+    bool transmitted = irr_glsl_partitionRandVariable(reflectance, u.z, rcpChoiceProb);
 
     vec3 localL;
-    _cache = irr_glsl_calcAnisotropicMicrofacetCache(localV,H,localL);
+    _cache = irr_glsl_calcAnisotropicMicrofacetCache(transmitted,localV,H,localL,rcpOrientedEta,rcpOrientedEta2);
 
     return irr_glsl_createLightSampleTangentSpace(localV,localL,m);
 }
 
-irr_glsl_LightSample irr_glsl_ggx_cos_generate(in irr_glsl_AnisotropicViewSurfaceInteraction interaction, in vec2 u, in float _ax, in float _ay, out irr_glsl_AnisotropicMicrofacetCache _cache)
+irr_glsl_LightSample irr_glsl_ggx_dielectric_cos_generate(in irr_glsl_AnisotropicViewSurfaceInteraction interaction, in vec3 u, in float ax, in float ay, in float eta, out irr_glsl_AnisotropicMicrofacetCache _cache)
 {
     const vec3 localV = irr_glsl_getTangentSpaceV(interaction);
+    
+    float orientedEta, rcpOrientedEta;
+    const bool backside = irr_glsl_getOrientedEtas(orientedEta, rcpOrientedEta, interaction.isotropic.NdotV, eta);
+    
+    const vec3 upperHemisphereV = backside ? (-localV):localV;
+
     const mat3 m = irr_glsl_getTangentFrame(interaction);
-    return irr_glsl_ggx_cos_generate_wo_clamps(localV,m,u,_ax,_ay,_cache);
+    return irr_glsl_ggx_dielectric_cos_generate_wo_clamps(localV,backside,upperHemisphereV,m, u,ax,ay, rcpOrientedEta,orientedEta*orientedEta,rcpOrientedEta*rcpOrientedEta,_cache);
 }
 
-
-
+#if 0
+// TODO
 float irr_glsl_ggx_pdf_wo_clamps(in float ndf, in float devsh_v, in float maxNdotV)
 {
-    return irr_glsl_smith_VNDF_pdf_wo_clamps(ndf,irr_glsl_GGXSmith_G1_wo_numerator(maxNdotV,devsh_v));
+    return irr_glsl_smith_VNDF_pdf_wo_clamps(ndf,irr_glsl_GGXSmith_G1_wo_numerator(maxNdotV,devsh_v),);
 }
 float irr_glsl_ggx_pdf_wo_clamps(in float NdotH2, in float maxNdotV, in float NdotV2, in float a2)
 {
@@ -187,5 +200,6 @@ vec3 irr_glsl_ggx_aniso_cos_remainder_and_pdf(out float pdf, in irr_glsl_LightSa
         return vec3(0.0);
     }
 }
+#endif
 
 #endif

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

@@ -9,10 +9,6 @@ float irr_glsl_smith_G1(in float lambda)
 }
 
 
-float irr_glsl_smith_VNDF_pdf_wo_clamps(in float ndf, in float G1_over_2NdotV)
-{
-    return ndf*0.5*G1_over_2NdotV;
-}
 
 float irr_glsl_smith_VNDF_pdf_wo_clamps(in float ndf, in float lambda_V, in float maxNdotV, out float onePlusLambda_V)
 {
@@ -21,24 +17,30 @@ float irr_glsl_smith_VNDF_pdf_wo_clamps(in float ndf, in float lambda_V, in floa
     return irr_glsl_microfacet_to_light_measure_transform(ndf/onePlusLambda_V,maxNdotV);
 }
 
+float irr_glsl_smith_VNDF_pdf_wo_clamps(in float ndf, in float lambda_V, in float absNdotV, in bool transmitted, in float VdotH, in float LdotH, in float VdotHLdotH, in float orientedEta, in float reflectance, out float onePlusLambda_V)
+{
+    onePlusLambda_V = 1.0+lambda_V;
+
+    return irr_glsl_microfacet_to_light_measure_transform((transmitted ? (1.0-reflectance):reflectance)*ndf/onePlusLambda_V,absNdotV,transmitted,VdotH,LdotH,VdotHLdotH,orientedEta);
+}
+
+
+float irr_glsl_smith_VNDF_pdf_wo_clamps(in float ndf, in float G1_over_2NdotV)
+{
+    return ndf*0.5*G1_over_2NdotV;
+}
 
 float irr_glsl_smith_VNDF_pdf_wo_clamps(in float ndf, in float G1_over_2NdotV, in float absNdotV, in bool transmitted, in float VdotH, in float LdotH, in float VdotHLdotH, in float orientedEta, in float reflectance)
 {
-    const float FNG = (transmitted ? (1.0-reflectance):reflectance)*ndf*G1_over_2NdotV;
+    float FNG = (transmitted ? (1.0-reflectance):reflectance)*ndf*G1_over_2NdotV;
+    float factor = 0.5;
     if (transmitted)
     {
         const float VdotH_etaLdotH = (VdotH+orientedEta*LdotH);
         // VdotHLdotH is negative under transmission, so this factor is negative
-        FNG *= -absNdotV*VdotHLdotH/(VdotH_etaLdotH*VdotH_etaLdotH);
+        factor *= -2.0*VdotHLdotH/(VdotH_etaLdotH*VdotH_etaLdotH);
     }
-    return FNG*(transmitted ? 2.0:0.5);
-}
-
-float irr_glsl_smith_VNDF_pdf_wo_clamps(in float ndf, in float lambda_V, in float absNdotV, in bool transmitted, in float VdotH, in float LdotH, in float VdotHLdotH, in float orientedEta, in float reflectance, out float onePlusLambda_V)
-{
-    onePlusLambda_V = 1.0+lambda_V;
-
-    return irr_glsl_microfacet_to_light_measure_transform((transmitted ? (1.0-reflectance):reflectance)*ndf/onePlusLambda_V,absNdotV,transmitted,VdotH,LdotH,VdotHLdotH,orientedEta);
+    return FNG*factor;
 }
 
 #endif

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

@@ -30,7 +30,7 @@ float irr_glsl_ggx_microfacet_to_light_measure_transform(in float NDFcos_already
     }
     return NDFcos_already_in_reflective_dL_measure*factor;
 }
-float irr_glsl_microfacet_to_light_measure_transform(in float ndf, in float maxNdotL)
+float irr_glsl_ggx_microfacet_to_light_measure_transform(in float NDFcos_already_in_reflective_dL_measure, in float maxNdotL)
 {
     return NDFcos_already_in_reflective_dL_measure*maxNdotL;
 }