#include "Macros.fxh" //from FNA static const float PI = 3.141592653589793; // Samplers DECLARE_TEXTURE(AlbedoTexture, 0); DECLARE_TEXTURE(NormalTexture, 1); DECLARE_TEXTURE(EmissionTexture, 2); DECLARE_TEXTURE(OcclusionTexture, 3); DECLARE_TEXTURE(MetallicRoughnessTexture, 4); DECLARE_CUBEMAP(EnvDiffuseTexture, 8); DECLARE_TEXTURE(BrdfLutTexture, 9); DECLARE_CUBEMAP(EnvSpecularTexture, 10); BEGIN_CONSTANTS // PBR Values float3 AlbedoValue _ps(c0) _cb(c0); float MetallicValue _ps(c1) _cb(c1); float RoughnessValue _ps(c2) _cb(c2); float AO _ps(c3) _cb(c3); // Light Info float3 LightPositions[4] _ps(c4) _cb(c4); float3 LightColors[4] _ps(c8) _cb(c8); float3 EyePosition _ps(c12) _cb(c12); float4x4 World _vs(c0) _cb(c16); float4x4 WorldInverseTranspose _vs(c4) _cb(c20); MATRIX_CONSTANTS float4x4 WorldViewProjection _vs(c8) _cb(c0); END_CONSTANTS struct VertexShaderInput { float4 Position : POSITION; float3 Normal : NORMAL; float2 TexCoord : TEXCOORD0; }; struct PixelShaderInput { float4 Position : SV_Position; float2 TexCoord : TEXCOORD0; float3 PositionWS : TEXCOORD1; float3 NormalWS : TEXCOORD2; }; PixelShaderInput main_vs(VertexShaderInput input) { PixelShaderInput output; output.TexCoord = input.TexCoord; output.PositionWS = mul(input.Position, World).xyz; output.NormalWS = mul(input.Normal, (float3x3)WorldInverseTranspose).xyz; output.Position = mul(input.Position, WorldViewProjection); return output; } float3 FresnelSchlick(float cosTheta, float3 F0) { return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0); } float DistributionGGX(float3 N, float3 H, float roughness) { float a = roughness * roughness; float a2 = a * a; float NdotH = max(dot(N, H), 0.0); float NdotH2 = NdotH * NdotH; float num = a2; float denom = (NdotH2 * (a2 - 1.0) + 1.0); denom = PI * denom * denom; return num / denom; } float GeometrySchlickGGX(float NdotV, float roughness) { float r = (roughness + 1.0); float k = (r * r) / 8.0; float num = NdotV; float denom = NdotV * (1.0 - k) + k; return num / denom; } float GeometrySmith(float3 N, float3 V, float3 L, float roughness) { float NdotV = max(dot(N, V), 0.0); float NdotL = max(dot(N, L), 0.0); float ggx2 = GeometrySchlickGGX(NdotV, roughness); float ggx1 = GeometrySchlickGGX(NdotL, roughness); return ggx1 * ggx2; } // Easy trick to get tangent-normals to world-space to keep PBR code simplified. float3 GetNormalFromMap(float3 worldPos, float2 texCoords, float3 normal) { float3 tangentNormal = SAMPLE_TEXTURE(NormalTexture, texCoords).xyz * 2.0 - 1.0; float3 Q1 = ddx(worldPos); float3 Q2 = ddy(worldPos); float2 st1 = ddx(texCoords); float2 st2 = ddy(texCoords); float3 N = normalize(normal); float3 T = normalize(Q1*st2.y - Q2*st1.y); float3 B = -normalize(cross(N, T)); float3x3 TBN = float3x3(T, B, N); return normalize(mul(tangentNormal, TBN)); } float4 ComputeColor( float3 worldPosition, float3 worldNormal, float3 albedo, float metallic, float roughness ) { float3 V = normalize(EyePosition - worldPosition); float3 N = worldNormal; float3 F0 = float3(0.04, 0.04, 0.04); F0 = lerp(F0, albedo, metallic); float3 Lo = float3(0.0, 0.0, 0.0); for (int i = 0; i < 4; i++) { float3 lightDir = LightPositions[i] - worldPosition; float3 L = normalize(lightDir); float3 H = normalize(V + L); float distance = length(lightDir); float attenuation = 1.0 / (distance * distance); float3 radiance = LightColors[i] * attenuation; float NDF = DistributionGGX(N, H, roughness); float G = GeometrySmith(N, V, L, roughness); float3 F = FresnelSchlick(max(dot(H, V), 0.0), F0); float3 numerator = NDF * G * F; float denominator = 4.0 * max(dot(N, V), 0.0) * max(dot(N, L), 0.0); float3 specular = numerator / max(denominator, 0.001); float3 kS = F; float3 kD = float3(1.0, 1.0, 1.0) - kS; kD *= 1.0 - metallic; float NdotL = max(dot(N, L), 0.0); Lo += (kD * albedo / PI + specular) * radiance * NdotL; } float3 ambient = float3(0.03, 0.03, 0.03) * albedo * AO; float3 color = ambient + Lo; color = color / (color + float3(1.0, 1.0, 1.0)); float exposureConstant = 1.0 / 2.2; color = pow(color, float3(exposureConstant, exposureConstant, exposureConstant)); return float4(color, 1.0); } // The case where we have no texture maps for any PBR data float4 None(PixelShaderInput input) : SV_TARGET0 { return ComputeColor( input.PositionWS, input.NormalWS, AlbedoValue, MetallicValue, RoughnessValue ); } float4 AlbedoMapPS(PixelShaderInput input) : SV_TARGET { float3 albedo = pow(SAMPLE_TEXTURE(AlbedoTexture, input.TexCoord), 2.2).rgb; return ComputeColor( input.PositionWS, input.NormalWS, albedo, MetallicValue, RoughnessValue ); } float4 MetallicRoughnessPS(PixelShaderInput input) : SV_TARGET { float2 metallicRoughness = SAMPLE_TEXTURE(MetallicRoughnessTexture, input.TexCoord).rg; return ComputeColor( input.PositionWS, input.NormalWS, AlbedoValue, metallicRoughness.r, metallicRoughness.g ); } float4 NormalPS(PixelShaderInput input) : SV_TARGET { float3 normal = GetNormalFromMap(input.PositionWS, input.TexCoord, input.NormalWS); return ComputeColor( input.PositionWS, normal, AlbedoValue, MetallicValue, RoughnessValue ); } float4 AlbedoMetallicRoughnessMapPS(PixelShaderInput input) : SV_TARGET { float3 albedo = pow(SAMPLE_TEXTURE(AlbedoTexture, input.TexCoord), 2.2).rgb; float2 metallicRoughness = SAMPLE_TEXTURE(MetallicRoughnessTexture, input.TexCoord).rg; return ComputeColor( input.PositionWS, input.NormalWS, albedo, metallicRoughness.r, metallicRoughness.g ); } float4 AlbedoNormalPS(PixelShaderInput input) : SV_TARGET { float3 albedo = pow(SAMPLE_TEXTURE(AlbedoTexture, input.TexCoord), 2.2).rgb; float3 normal = GetNormalFromMap(input.PositionWS, input.TexCoord, input.NormalWS); return ComputeColor( input.PositionWS, normal, albedo, MetallicValue, RoughnessValue ); } float4 MetallicRoughnessNormalPS(PixelShaderInput input) : SV_TARGET { float2 metallicRoughness = SAMPLE_TEXTURE(MetallicRoughnessTexture, input.TexCoord).rg; float3 normal = GetNormalFromMap(input.PositionWS, input.TexCoord, input.NormalWS); return ComputeColor( input.PositionWS, normal, AlbedoValue, metallicRoughness.r, metallicRoughness.g ); } float4 AlbedoMetallicRoughnessNormalMapPS(PixelShaderInput input) : SV_TARGET { float3 albedo = pow(SAMPLE_TEXTURE(AlbedoTexture, input.TexCoord), 2.2).rgb; float2 metallicRoughness = SAMPLE_TEXTURE(MetallicRoughnessTexture, input.TexCoord).rg; float3 normal = GetNormalFromMap(input.PositionWS, input.TexCoord, input.NormalWS); return ComputeColor( input.PositionWS, normal, albedo, metallicRoughness.r, metallicRoughness.g ); } PixelShader PSArray[8] = { compile ps_3_0 None(), compile ps_3_0 AlbedoMapPS(), compile ps_3_0 MetallicRoughnessPS(), compile ps_3_0 NormalPS(), compile ps_3_0 AlbedoMetallicRoughnessMapPS(), compile ps_3_0 AlbedoNormalPS(), compile ps_3_0 MetallicRoughnessNormalPS(), compile ps_3_0 AlbedoMetallicRoughnessNormalMapPS() }; int ShaderIndex = 0; Technique PBR { Pass { VertexShader = compile vs_3_0 main_vs(); PixelShader = (PSArray[ShaderIndex]); } }