Directional Light PBR.

samples/03_model_render/model_render.cpp

@@ -90,7 +90,7 @@ main(int, char **)
         .m_Position = vec4{0.0f, 2.0f, 2.0f, 1.0f},
     };
 
-    //lightManager.AddDirectional(vec3(0.0f, -1.0f, 0.0f), {0.0f, 1.0f, 0.0f});
+    lightManager.AddDirectional(vec3(0.0f, -1.0f, 0.0f), {0.0f, 0.7f, 0.0f});
     lightManager.AddPoint(vec3{2.0f, 1.0f, 0.0f}, {1.0f, 0.0f, 0.0f}, 15.0f);
     lightManager.AddPoint(vec3{-2.0f, 1.0f, 0.0f}, {0.0f, 0.0f, 1.0f}, 15.0f);
 

samples/03_model_render/shader/bindless_structs.hlsli

@@ -34,7 +34,7 @@ struct Block
     uint NodeBufferHandle;
     uint LightHandle;
     uint PointLightIndexer;
-    uint DirectionLightIndexer;
+    uint DirectionalLightIndexer;
     int MaterialIdx;
     uint NodeIdx;
 };

samples/03_model_render/shader/model.ps.hlsl

@@ -100,6 +100,33 @@ float3 FresnelSchlick(float cosine, float3 F_0)
     return F_0 + (1.0f - F_0) * pow(clamp(1.0f - cosine, 0.0f, 1.0f), 5.0f);   // Clamp to avoid artifacts.
 }
 
+float3 GetPBRContrib(float3 Albedo, float3 LightColor, float3 ViewDir, float3 Normal, float Metallic, float Roughness, float3 F_0, float3 LightDir, float LightDistance)
+{
+    float Attenuation = 1.0f / (LightDistance * LightDistance); // TODO: Controlled Attenuation
+    float3 Halfway = normalize(ViewDir + LightDir);
+        
+    float CosineFactor = max(dot(Halfway, ViewDir), 0.0f);
+    float NdotV = max(dot(Normal, ViewDir), 0.0f);
+    float NdotL = max(dot(Normal, LightDir), 0.0f);
+        
+    float3 Radiance = LightColor * Attenuation;
+        
+    float NormalDistribution = TrowbridgeReitzGGX(Normal, Halfway, Roughness);
+    float Geometry = GeometrySmith(NdotV, NdotL, Roughness);
+    float3 Fresnel = FresnelSchlick(CosineFactor, F_0);
+        
+    float3 Numerator = (NormalDistribution * Geometry) * Fresnel;
+    float Denominator = 4.0f * NdotV * NdotL;
+    float3 Specular = Numerator / max(Denominator, 0.00001);
+        
+    float3 K_Specular = Fresnel;
+    float3 K_Diffuse = 1.0f.xxx - K_Specular;
+        
+    K_Diffuse *= 1.0f - Metallic;
+        
+    return NdotL * Radiance * ((K_Diffuse * Albedo / PI) + Specular);
+}
+
 float3 GetPointLightInfluence(float3 Albedo, float2 MetalRough, float3 Position, float3 Normal)
 {
     if (PushConstant.LightHandle == INVALID_HANDLE) 
@@ -117,7 +144,7 @@ float3 GetPointLightInfluence(float3 Albedo, float2 MetalRough, float3 Position,
     // TODO: Cite    
     float3 F_0 = 0.04f.xxx;
     F_0 = lerp(F_0, Albedo, Metallic);
-    float3 LightAmp = float3(23.47f, 21.31f, 20.79f);
+    float3 LightAmp = float3(23.47f, 21.31f, 20.79f); // TODO: Get rid
     
     float3 Contrib = 0.0f;
     for (uint i = 0; i < Count; ++i)
@@ -142,29 +169,49 @@ float3 GetPointLightInfluence(float3 Albedo, float2 MetalRough, float3 Position,
         
         float3 LightColor = LightAmp * float3(R, G, B) * 0.00392156862f; // 0.00392156862 = 1/255
  
-        float Attenuation = 1.0f / (LightDistance * LightDistance);     // TODO: Controlled Attenuation
+        Contrib += GetPBRContrib(Albedo, LightColor, ViewDir, Normal, Metallic, Roughness, F_0, LightDir, LightDistance);
-        float3 Halfway = normalize(ViewDir + LightDir);
+    }
     
-        float CosineFactor = max(dot(Halfway, ViewDir), 0.0f);
+    return Contrib;
-        float NdotV = max(dot(Normal, ViewDir), 0.0f);
+}
-        float NdotL = max(dot(Normal, LightDir), 0.0f);
 
-        float3 Radiance = LightColor * Attenuation;
 
-        float NormalDistribution = TrowbridgeReitzGGX(Normal, Halfway, Roughness);
+float3 GetDirectionalLightInfluence(float3 Albedo, float2 MetalRough, float3 Position, float3 Normal)
-        float Geometry = GeometrySmith(NdotV, NdotL, Roughness);
+{
-        float3 Fresnel = FresnelSchlick(CosineFactor, F_0);
+    if (PushConstant.LightHandle == INVALID_HANDLE) 
+        return 0.0f.xxx;
     
-        float3 Numerator = (NormalDistribution * Geometry) * Fresnel;
+    uint Count = IndexerCount(PushConstant.DirectionalLightIndexer);
-        float Denominator = 4.0f * NdotV * NdotL;
-        float3 Specular = Numerator / max(Denominator, 0.00001);
     
-        float3 K_Specular = Fresnel;
+    float3 ViewDir = normalize(Camera.Position.xyz - Position);
-        float3 K_Diffuse = 1.0f.xxx - K_Specular;
     
-        K_Diffuse *= 1.0f - Metallic;
+    float Metallic = MetalRough.r;
+    float Roughness = MetalRough.g;
     
-        Contrib += NdotL * Radiance * ((K_Diffuse * Albedo / PI) + Specular);
+    // Dielectric F_0 based on LearnOpenGL.
+    // TODO: Cite    
+    float3 F_0 = 0.04f.xxx;
+    F_0 = lerp(F_0, Albedo, Metallic);
+    float3 LightAmp = float3(23.47f, 21.31f, 20.79f); // TODO: Get rid
+    
+    float3 Contrib = 0.0f;
+    for (uint i = 0; i < Count; ++i)
+    {
+        DirectionalLight Light = DirectionalLightBuffer[PushConstant.LightHandle][i];
+        
+        if (Light.Validity_ < 0.0f)
+            continue;
+        
+        float3 LightDir = -normalize(float3(Light.Direction));
+        
+        // Color Unpack
+        float R = (Light.Color & 0xFF000000) >> 24;
+        float G = (Light.Color & 0x00FF0000) >> 16;
+        float B = (Light.Color & 0x0000FF00) >> 8;
+        
+        float3 LightColor = LightAmp * float3(R, G, B) * 0.00392156862f; // 0.00392156862 = 1/255
+ 
+        Contrib += GetPBRContrib(Albedo, LightColor, ViewDir, Normal, Metallic, Roughness, F_0, LightDir, 1.0f);
     }
     
     return Contrib;
@@ -203,7 +250,7 @@ FS_Output main(FS_Input StageInput)
     float Alpha = AlbedoAlpha.a;
     float2 MetalRough = GetMetalRough(StageInput.InUV0);
     float3 Emission = GetEmissive(StageInput.InUV0);
-    float3 Color = /*GetDirectionalLightInfluence(Albedo, MetalRough, Position, Normal) +*/ GetPointLightInfluence(Albedo, MetalRough, Position, Normal);
+    float3 Color = GetDirectionalLightInfluence(Albedo, MetalRough, Position, Normal) + GetPointLightInfluence(Albedo, MetalRough, Position, Normal);
     
     Output.ColorTarget = float4(Uncharted2Tonemap(Color + Emission), Alpha);
     return Output;