delete old pbr effect code
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964e02c570
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3f89495585
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@ -1,410 +0,0 @@
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#include "Macros.fxh"
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#define NORMALS
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#define UV
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#define HAS_BASECOLORMAP
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// A constant buffer that stores the three basic column-major matrices for composing geometry.
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cbuffer ModelViewProjectionConstantBuffer : register(b0)
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{
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matrix model;
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matrix view;
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matrix projection;
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};
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// Per-vertex data used as input to the vertex shader.
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struct VertexShaderInput
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{
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float4 position : POSITION;
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#ifdef NORMALS
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float3 normal : NORMAL;
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#endif
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#ifdef UV
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float2 texcoord : TEXCOORD0;
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#endif
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};
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// Per-pixel color data passed through the pixel shader.
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struct PixelShaderInput
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{
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float4 position : SV_POSITION;
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float4 positionWS : TEXCOORD1;
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float3 normalWS : TEXCOORD2;
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#ifdef NORMALS
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float3 normal : NORMAL;
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#endif
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float2 texcoord : TEXCOORD0;
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};
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PixelShaderInput main_vs(VertexShaderInput input)
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{
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PixelShaderInput output;
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// Transform the vertex position into projected space.
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float4 pos = mul(input.position, model);
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#ifdef NORMALS
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// If we have normals...
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output.normal = normalize(mul(float4(input.normal.xyz, 0.0), model));
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#endif
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#ifdef UV
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output.texcoord = input.texcoord;
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#else
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output.texcoord = float2(0.0f, 0.0f);
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#endif
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#ifdef HAS_NORMALS
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#ifdef HAS_TANGENTS
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vec3 normalW = normalize(vec3(u_ModelMatrix * vec4(a_Normal.xyz, 0.0)));
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vec3 tangentW = normalize(vec3(u_ModelMatrix * vec4(a_Tangent.xyz, 0.0)));
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vec3 bitangentW = cross(normalW, tangentW) * a_Tangent.w;
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v_TBN = mat3(tangentW, bitangentW, normalW);
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#else // HAS_TANGENTS != 1
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v_Normal = normalize(vec3(u_ModelMatrix * vec4(a_Normal.xyz, 0.0)));
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#endif
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#endif
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// Transform the vertex position into projected space.
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pos = mul(pos, view);
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pos = mul(pos, projection);
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output.position = pos;
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return output;
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}
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//
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// This fragment shader defines a reference implementation for Physically Based Shading of
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// a microfacet surface material defined by a glTF model.
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//
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// References:
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// [1] Real Shading in Unreal Engine 4
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// http://blog.selfshadow.com/publications/s2013-shading-course/karis/s2013_pbs_epic_notes_v2.pdf
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// [2] Physically Based Shading at Disney
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// http://blog.selfshadow.com/publications/s2012-shading-course/burley/s2012_pbs_disney_brdf_notes_v3.pdf
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// [3] README.md - Environment Maps
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// https://github.com/KhronosGroup/glTF-WebGL-PBR/#environment-maps
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// [4] "An Inexpensive BRDF Model for Physically based Rendering" by Christophe Schlick
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// https://www.cs.virginia.edu/~jdl/bib/appearance/analytic%20models/schlick94b.pdf
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#define NORMALS
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#define UV
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#define HAS_NORMALS
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// #define USE_IBL
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#define USE_TEX_LOD
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DECLARE_TEXTURE(baseColourTexture, 0);
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DECLARE_TEXTURE(normalTexture, 1);
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DECLARE_TEXTURE(emissionTexture, 2);
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DECLARE_TEXTURE(occlusionTexture, 3);
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DECLARE_TEXTURE(metallicRoughnessTexture, 4);
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DECLARE_CUBEMAP(envDiffuseTexture, 8);
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DECLARE_TEXTURE(brdfLutTexture, 9);
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DECLARE_CUBEMAP(envSpecularTexture, 10);
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cbuffer cbPerFrame : register(b0)
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{
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float3 lightDir;
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float3 lightColour;
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};
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cbuffer cbPerObject : register(b1)
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{
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float normalScale;
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float3 emissiveFactor;
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float occlusionStrength;
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float2 metallicRoughnessValues;
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float4 baseColorFactor;
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float3 camera;
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// debugging flags used for shader output of intermediate PBR variables
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float4 scaleDiffBaseMR;
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float4 scaleFGDSpec;
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float4 scaleIBLAmbient;
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};
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#ifdef HAS_NORMALS
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#ifdef HAS_TANGENTS
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varying mat3 v_TBN;
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#else
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#endif
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#endif
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// Encapsulate the various inputs used by the various functions in the shading equation
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// We store values in this struct to simplify the integration of alternative implementations
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// of the shading terms, outlined in the Readme.MD Appendix.
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struct PBRInfo
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{
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float NdotL; // cos angle between normal and light direction
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float NdotV; // cos angle between normal and view direction
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float NdotH; // cos angle between normal and half vector
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float LdotH; // cos angle between light direction and half vector
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float VdotH; // cos angle between view direction and half vector
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float perceptualRoughness; // roughness value, as authored by the model creator (input to shader)
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float metalness; // metallic value at the surface
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float3 reflectance0; // full reflectance color (normal incidence angle)
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float3 reflectance90; // reflectance color at grazing angle
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float alphaRoughness; // roughness mapped to a more linear change in the roughness (proposed by [2])
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float3 diffuseColor; // color contribution from diffuse lighting
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float3 specularColor; // color contribution from specular lighting
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};
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static const float M_PI = 3.141592653589793;
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static const float c_MinRoughness = 0.04;
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float4 SRGBtoLINEAR(float4 srgbIn)
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{
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#ifdef MANUAL_SRGB
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#ifdef SRGB_FAST_APPROXIMATION
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float3 linOut = pow(srgbIn.xyz,float3(2.2, 2.2, 2.2));
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#else //SRGB_FAST_APPROXIMATION
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float3 bLess = step(float3(0.04045, 0.04045, 0.04045), srgbIn.xyz);
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float3 linOut = lerp(srgbIn.xyz / float3(12.92, 12.92, 12.92), pow((srgbIn.xyz + float3(0.055, 0.055, 0.055)) / float3(1.055, 1.055, 1.055), float3(2.4, 2.4, 2.4)), bLess);
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#endif //SRGB_FAST_APPROXIMATION
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return float4(linOut,srgbIn.w);;
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#else //MANUAL_SRGB
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return srgbIn;
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#endif //MANUAL_SRGB
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}
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// Find the normal for this fragment, pulling either from a predefined normal map
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// or from the interpolated mesh normal and tangent attributes.
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float3 getNormal(float3 position, float3 normal, float2 uv)
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{
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// Retrieve the tangent space matrix
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#ifndef HAS_TANGENTS
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float3 pos_dx = ddx(position);
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float3 pos_dy = ddy(position);
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float3 tex_dx = ddx(float3(uv, 0.0));
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float3 tex_dy = ddy(float3(uv, 0.0));
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float3 t = (tex_dy.y * pos_dx - tex_dx.y * pos_dy) / (tex_dx.x * tex_dy.y - tex_dy.x * tex_dx.y);
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#ifdef HAS_NORMALS
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float3 ng = normalize(normal);
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#else
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float3 ng = cross(pos_dx, pos_dy);
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#endif
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t = normalize(t - ng * dot(ng, t));
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float3 b = normalize(cross(ng, t));
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row_major float3x3 tbn = float3x3(t, b, ng);
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#else // HAS_TANGENTS
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mat3 tbn = v_TBN;
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#endif
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#ifdef HAS_NORMALMAP
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float3 n = SAMPLE_TEXTURE(normalTexture, uv).rgb;
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// Need to check the multiplication is equivalent..
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n = normalize(mul(((2.0 * n - 1.0) * float3(normalScale, normalScale, 1.0)), tbn));
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#else
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float3 n = tbn[2].xyz;
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#endif
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return n;
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}
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#ifdef USE_IBL
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// Calculation of the lighting contribution from an optional Image Based Light source.
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// Precomputed Environment Maps are required uniform inputs and are computed as outlined in [1].
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// See our README.md on Environment Maps [3] for additional discussion.
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float3 getIBLContribution(PBRInfo pbrInputs, float3 n, float3 reflection)
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{
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float mipCount = 9.0; // resolution of 512x512
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float lod = (pbrInputs.perceptualRoughness * mipCount);
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// retrieve a scale and bias to F0. See [1], Figure 3
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float2 val = float2(pbrInputs.NdotV, 1.0 - pbrInputs.perceptualRoughness);
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float3 brdf = SRGBtoLINEAR(SAMPLE_TEXTURE(brdfLutTexture, val)).rgb;
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float3 diffuseLight = SRGBtoLINEAR(SAMPLE_CUBEMAP(envDiffuseTexture, n)).rgb;
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#ifdef USE_TEX_LOD
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float4 reflectionWithLOD = float4(reflection, 0);
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float3 specularLight = SRGBtoLINEAR(SAMPLE_CUBEMAP_LOD(envSpecularTexture, reflectionWithLOD)).rgb;
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#else
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float3 specularLight = SRGBtoLINEAR(SAMPLE_CUBEMAP(envSpecularTexture, reflection)).rgb;
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#endif
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float3 diffuse = diffuseLight * pbrInputs.diffuseColor;
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float3 specular = specularLight * (pbrInputs.specularColor * brdf.x + brdf.y);
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// For presentation, this allows us to disable IBL terms
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diffuse *= scaleIBLAmbient.x;
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specular *= scaleIBLAmbient.y;
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return diffuse + specular;
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}
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#endif
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// Basic Lambertian diffuse
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// Implementation from Lambert's Photometria https://archive.org/details/lambertsphotome00lambgoog
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// See also [1], Equation 1
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float3 diffuse(PBRInfo pbrInputs)
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{
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return pbrInputs.diffuseColor / M_PI;
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}
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// The following equation models the Fresnel reflectance term of the spec equation (aka F())
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// Implementation of fresnel from [4], Equation 15
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float3 specularReflection(PBRInfo pbrInputs)
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{
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return pbrInputs.reflectance0 + (pbrInputs.reflectance90 - pbrInputs.reflectance0) * pow(clamp(1.0 - pbrInputs.VdotH, 0.0, 1.0), 5.0);
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}
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// This calculates the specular geometric attenuation (aka G()),
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// where rougher material will reflect less light back to the viewer.
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// This implementation is based on [1] Equation 4, and we adopt their modifications to
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// alphaRoughness as input as originally proposed in [2].
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float geometricOcclusion(PBRInfo pbrInputs)
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{
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float NdotL = pbrInputs.NdotL;
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float NdotV = pbrInputs.NdotV;
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float r = pbrInputs.alphaRoughness;
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float attenuationL = 2.0 * NdotL / (NdotL + sqrt(r * r + (1.0 - r * r) * (NdotL * NdotL)));
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float attenuationV = 2.0 * NdotV / (NdotV + sqrt(r * r + (1.0 - r * r) * (NdotV * NdotV)));
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return attenuationL * attenuationV;
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}
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// The following equation(s) model the distribution of microfacet normals across the area being drawn (aka D())
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// Implementation from "Average Irregularity Representation of a Roughened Surface for Ray Reflection" by T. S. Trowbridge, and K. P. Reitz
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// Follows the distribution function recommended in the SIGGRAPH 2013 course notes from EPIC Games [1], Equation 3.
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float microfacetDistribution(PBRInfo pbrInputs)
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{
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float roughnessSq = pbrInputs.alphaRoughness * pbrInputs.alphaRoughness;
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float f = (pbrInputs.NdotH * roughnessSq - pbrInputs.NdotH) * pbrInputs.NdotH + 1.0;
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return roughnessSq / (M_PI * f * f);
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}
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float4 main_ps(PixelShaderInput input) : SV_TARGET
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{
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// Metallic and Roughness material properties are packed together
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// In glTF, these factors can be specified by fixed scalar values
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// or from a metallic-roughness map
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float perceptualRoughness = metallicRoughnessValues.y;
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float metallic = metallicRoughnessValues.x;
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#ifdef HAS_METALROUGHNESSMAP
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// Roughness is stored in the 'g' channel, metallic is stored in the 'b' channel.
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// This layout intentionally reserves the 'r' channel for (optional) occlusion map data
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float4 mrSample = SAMPLE_TEXTURE(metallicRoughnessTexture, input.texcoord);
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// Had to reverse the order of the channels here - TODO: investigate..
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perceptualRoughness = mrSample.g * perceptualRoughness;
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metallic = mrSample.b * metallic;
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#endif
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perceptualRoughness = clamp(perceptualRoughness, c_MinRoughness, 1.0);
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metallic = clamp(metallic, 0.0, 1.0);
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// Roughness is authored as perceptual roughness; as is convention,
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// convert to material roughness by squaring the perceptual roughness [2].
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float alphaRoughness = perceptualRoughness * perceptualRoughness;
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// The albedo may be defined from a base texture or a flat color
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#ifdef HAS_BASECOLORMAP
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float4 baseColor = SRGBtoLINEAR(SAMPLE_TEXTURE(baseColourTexture, input.texcoord)) * baseColorFactor;
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#else
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float4 baseColor = baseColorFactor;
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#endif
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float3 f0 = float3(0.04, 0.04, 0.04);
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float3 diffuseColor = baseColor.rgb * (float3(1.0, 1.0, 1.0) - f0);
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diffuseColor *= 1.0 - metallic;
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float3 specularColor = lerp(f0, baseColor.rgb, metallic);
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// Compute reflectance.
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float reflectance = max(max(specularColor.r, specularColor.g), specularColor.b);
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// For typical incident reflectance range (between 4% to 100%) set the grazing reflectance to 100% for typical fresnel effect.
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// For very low reflectance range on highly diffuse objects (below 4%), incrementally reduce grazing reflecance to 0%.
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float reflectance90 = clamp(reflectance * 25.0, 0.0, 1.0);
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float3 specularEnvironmentR0 = specularColor.rgb;
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float3 specularEnvironmentR90 = float3(1.0, 1.0, 1.0) * reflectance90;
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float3 n = getNormal(input.poswithoutw, input.normal, input.texcoord); // normal at surface point
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float3 v = normalize(camera - input.poswithoutw); // Vector from surface point to camera
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float3 l = normalize(lightDir); // Vector from surface point to light
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float3 h = normalize(l + v); // Half vector between both l and v
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float3 reflection = -normalize(reflect(v, n));
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float NdotL = clamp(dot(n, l), 0.001, 1.0);
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float NdotV = abs(dot(n, v)) + 0.001;
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float NdotH = clamp(dot(n, h), 0.0, 1.0);
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float LdotH = clamp(dot(l, h), 0.0, 1.0);
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float VdotH = clamp(dot(v, h), 0.0, 1.0);
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PBRInfo pbrInputs;
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pbrInputs.NdotL = NdotL;
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pbrInputs.NdotV = NdotV;
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pbrInputs.NdotH = NdotH;
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pbrInputs.LdotH = LdotH;
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pbrInputs.VdotH = VdotH;
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pbrInputs.perceptualRoughness = perceptualRoughness;
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pbrInputs.metalness = metallic;
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pbrInputs.reflectance0 = specularEnvironmentR0;
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pbrInputs.reflectance90 = specularEnvironmentR90;
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pbrInputs.alphaRoughness = alphaRoughness;
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pbrInputs.diffuseColor = diffuseColor;
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pbrInputs.specularColor = specularColor;
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// Calculate the shading terms for the microfacet specular shading model
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float3 F = specularReflection(pbrInputs);
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float G = geometricOcclusion(pbrInputs);
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float D = microfacetDistribution(pbrInputs);
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// Calculation of analytical lighting contribution
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float3 diffuseContrib = (1.0 - F) * diffuse(pbrInputs);
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float3 specContrib = F * G * D / (4.0 * NdotL * NdotV);
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float3 color = NdotL * lightColour * (diffuseContrib + specContrib);
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// Calculate lighting contribution from image based lighting source (IBL)
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#ifdef USE_IBL
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color += getIBLContribution(pbrInputs, n, reflection);
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#endif
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// Apply optional PBR terms for additional (optional) shading
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#ifdef HAS_OCCLUSIONMAP
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float ao = SAMPLE_TEXTURE(occlusionTexture, input.texcoord).r;
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color = lerp(color, color * ao, occlusionStrength);
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#endif
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#ifdef HAS_EMISSIVEMAP
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float3 emissive = SRGBtoLINEAR(SAMPLE_TEXTURE(emissionTexture, input.texcoord)).rgb * emissiveFactor;
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color += emissive;
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#endif
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// This section uses lerp to override final color for reference app visualization
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// of various parameters in the lighting equation.
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color = lerp(color, F, scaleFGDSpec.x);
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color = lerp(color, float3(G, G, G), scaleFGDSpec.y);
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color = lerp(color, float3(D, D, D), scaleFGDSpec.z);
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color = lerp(color, specContrib, scaleFGDSpec.w);
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color = lerp(color, diffuseContrib, scaleDiffBaseMR.x);
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color = lerp(color, baseColor.rgb, scaleDiffBaseMR.y);
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color = lerp(color, float3(metallic, metallic, metallic), scaleDiffBaseMR.z);
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color = lerp(color, float3(perceptualRoughness, perceptualRoughness, perceptualRoughness), scaleDiffBaseMR.w);
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//return float4(baseColor.xyz, 1.0);
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return float4(color, 1.0);
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}
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Technique PBR
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{
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Pass pass1
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{
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VertexShader = compile vs_3_0 main_vs();
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PixelShader = compile ps_3_0 main_ps();
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}
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}
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