diff options
| -rw-r--r-- | yum_brdf.cginc | 67 | ||||
| -rw-r--r-- | yum_lighting.cginc | 11 |
2 files changed, 55 insertions, 23 deletions
diff --git a/yum_brdf.cginc b/yum_brdf.cginc index 170451d..224afc6 100644 --- a/yum_brdf.cginc +++ b/yum_brdf.cginc @@ -10,6 +10,14 @@ #include "yum_pbr.cginc" #include "yum_lighting.cginc" +// Define Filament quality levels for proper f90 calculation +#ifndef FILAMENT_QUALITY +#define FILAMENT_QUALITY_LOW 0 +#define FILAMENT_QUALITY_NORMAL 1 +#define FILAMENT_QUALITY_HIGH 2 +#define FILAMENT_QUALITY FILAMENT_QUALITY_NORMAL +#endif + #if defined(_MATERIAL_TYPE_CLOTH) float D_Charlie(float roughness, float NoH) { // Estevez and Kulla 2017, "Production Friendly Microfacet Sheen BRDF" @@ -25,7 +33,7 @@ float V_Cloth(float NoV, float NoL) { return 1.0 / (4.0 * (NoL + NoV - NoL * NoV)); } -float3 specularLobe(YumPbr pbr, float f0, +float3 specularLobe(YumPbr pbr, float3 f0, float3 h, float LoH, float NoH, float NoV, float NoL) { #if defined(_MATERIAL_TYPE_CLOTH) @@ -34,9 +42,13 @@ float3 specularLobe(YumPbr pbr, float f0, float3 F = _Cloth_Sheen_Color; return (D * V) * F; #else - // Fresnel - float f90 = 0.5 + 2.0 * pbr.roughness * LoH * LoH; + // Use Filament's proper f90 calculation for better energy conservation +#if FILAMENT_QUALITY == FILAMENT_QUALITY_LOW + const float3 F = F_Schlick(f0, LoH); // f90 = 1.0 +#else + float f90 = saturate(dot(f0, (50.0 * 0.33))); const float3 F = F_Schlick(f0, f90, LoH); +#endif // Normal distribution function float D = D_GGX(pbr.roughness, NoH, h); // Geometric shadowing @@ -49,6 +61,10 @@ float computeDielectricF0(float reflectance) { return 0.16 * reflectance * reflectance; } +float3 computeDiffuseColor(float3 baseColor, float metallic) { + return baseColor * (1.0 - metallic); +} + float computeSpecularAO(float NoV, float visibility, float roughness) { // Lagarde and de Rousiers 2014, "Moving Frostbite to PBR" return saturate(pow(NoV + visibility, exp2(-16.0 * roughness - 1.0)) - 1.0 + visibility); @@ -72,15 +88,13 @@ float4 YumBRDF(v2f i, const YumLighting light, YumPbr pbr) { const float NoV = max(1E-4, dot(pbr.normal, light.view_dir)); const float NoH = saturate(dot(pbr.normal, h)); const float VoL = saturate(dot(light.view_dir, light.dir)); - const float f90 = 0.5 + 2 * pbr.roughness * LoH * LoH; #if defined(_MATERIAL_TYPE_CLOTH) // Cloth specific BRDF float3 direct_cloth; { - // Cloth diffuse BRDF - apply proper energy conservation - // Use a proper diffuse BRDF term instead of raw albedo - float3 Fd = pbr.albedo / PI; + // Cloth diffuse BRDF - use Fd_Lambert and multiply by PI to match Unity intensities + float3 Fd = pbr.albedo * Fd_Lambert() * PI; Fd *= light.attenuation; #if defined(_MATERIAL_TYPE_CLOTH_SUBSURFACE) @@ -91,8 +105,8 @@ float4 YumBRDF(v2f i, const YumLighting light, YumPbr pbr) { Fd *= saturate(_Cloth_Subsurface_Color + NoL); #endif - // Cloth specular BRDF - float3 Fr = specularLobe(pbr, 0.04, h, LoH, NoH, NoV, NoL_wrapped_s) * light.attenuation; + // Cloth specular BRDF - multiply by PI to match Unity intensities + float3 Fr = specularLobe(pbr, float3(0.04, 0.04, 0.04), h, LoH, NoH, NoV, NoL_wrapped_s) * PI * light.attenuation; #if defined(_MATERIAL_TYPE_CLOTH_SUBSURFACE) // No need to multiply by NoL when using subsurface scattering @@ -105,21 +119,26 @@ float4 YumBRDF(v2f i, const YumLighting light, YumPbr pbr) { float3 direct_standard; { - // Typical values for different materials listed here: - // https://google.github.io/filament/Filament.html#toc4.8.3.2 - // TODO expose an enum for different types of materials - const float reflectance = computeDielectricF0(_reflectance); + // Fix reflectance calculation - _reflectance is already a 0-1 value, not an f0 value + // Default reflectance for dielectrics is typically 0.5, which gives f0 = 0.04 + const float dielectric_f0 = _reflectance; // f0 = amount of light reflected back when viewing surface at a right angle - // Change to match the design document - const float3 f0 = lerp(reflectance, pbr.albedo, pbr.metallic); + const float3 f0 = lerp(dielectric_f0, pbr.albedo, pbr.metallic); const float3 dfg = PrefilteredDFG_LUT(pbr.roughness_perceptual, NoV); const float3 E = specularDFG(dfg, f0); const float3 energy_compensation = energyCompensation(dfg, f0); - float3 Fd = pbr.albedo * Fd_Burley(pbr.roughness, NoV, NoL, LoH); - Fd *= (1.0 - pbr.metallic) * light.attenuation * pbr.ao; - float3 Fr = specularLobe(pbr, f0, h, LoH, NoH, NoV, NoL_wrapped_s) * pbr.ao * PI * light.attenuation; - + // Compute proper diffuse color with metallic blending + float3 diffuseColor = computeDiffuseColor(pbr.albedo, pbr.metallic); + + // Fd_Burley already includes 1/PI, so multiply by PI to match Unity intensities + float3 Fd = diffuseColor * Fd_Burley(pbr.roughness, NoV, NoL, LoH) * PI; + Fd *= light.attenuation * pbr.ao; + + // Multiply by PI to match Unity intensities (same as Filament's implementation) + float3 Fr = specularLobe(pbr, f0, h, LoH, NoH, NoV, NoL_wrapped_s) * PI * light.attenuation; + + // Apply energy compensation to specular term float3 color = Fd * NoL_wrapped_d + Fr * energy_compensation * NoL_wrapped_s; direct_standard = color * light.direct; } @@ -144,8 +163,8 @@ float4 YumBRDF(v2f i, const YumLighting light, YumPbr pbr) { float3 indirect_standard; { - const float reflectance = computeDielectricF0(_reflectance); - const float3 f0 = reflectance * (1.0 - pbr.metallic) + pbr.albedo * pbr.metallic; + const float dielectric_f0 = computeDielectricF0(_reflectance); + const float3 f0 = lerp(dielectric_f0, pbr.albedo, pbr.metallic); const float3 dfg = PrefilteredDFG_LUT(pbr.roughness_perceptual, NoV); const float3 E = specularDFG(dfg, f0); const float3 energy_compensation = energyCompensation(dfg, f0); @@ -155,7 +174,11 @@ float4 YumBRDF(v2f i, const YumLighting light, YumPbr pbr) { float specularAO = computeSpecularAO(NoV, diffuseAO * light.occlusion, pbr.roughness); float3 specularSingleBounceAO = singleBounceAO(specularAO) * energy_compensation; - float3 Fd = pbr.albedo * light.diffuse * (1.0 - E) * (1.0 - pbr.metallic) * pbr.ao; + // Use proper diffuse color calculation + float3 diffuseColor = computeDiffuseColor(pbr.albedo, pbr.metallic); + float3 Fd = diffuseColor * light.diffuse * (1.0 - E) * pbr.ao; + + // Apply energy compensation to indirect specular (critical fix) float3 Fr = E * light.specular * specularSingleBounceAO; indirect_standard = Fr + Fd; diff --git a/yum_lighting.cginc b/yum_lighting.cginc index e769375..ade45ae 100644 --- a/yum_lighting.cginc +++ b/yum_lighting.cginc @@ -113,6 +113,13 @@ float3 getDirectLightDirection(v2f i) { #endif } +float4 getDirectLightColorIntensity() { + // Properly separate light color from intensity like filamented + if (_LightColor0.w <= 0) return float4(0, 0, 0, 0); + _LightColor0 += 0.000001; // Avoid division by zero + return float4(_LightColor0.xyz / _LightColor0.w, _LightColor0.w); +} + float GetLodRoughness(float roughness) { return roughness * (1.7 - 0.7 * roughness); } @@ -195,7 +202,9 @@ YumLighting GetYumLighting(v2f i, YumPbr pbr) { light.dir = getDirectLightDirection(i); - light.direct = _LightColor0.rgb; + // Use proper light color/intensity separation + float4 lightColorIntensity = getDirectLightColorIntensity(); + light.direct = lightColorIntensity.rgb * lightColorIntensity.w; // Calculate attenuation first, before diffuse lighting light.attenuation = getShadowAttenuation(i); |