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delete old pbr effect code

PBR
cosmonaut 2020-08-03 17:36:23 -07:00
parent 964e02c570
commit 3f89495585
1 changed files with 0 additions and 410 deletions
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Effects/ReferencePBREffect.fx
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#include "Macros.fxh"
#define NORMALS
#define UV
#define HAS_BASECOLORMAP
// A constant buffer that stores the three basic column-major matrices for composing geometry.
cbuffer ModelViewProjectionConstantBuffer : register(b0)
{
matrix model;
matrix view;
matrix projection;
};
// Per-vertex data used as input to the vertex shader.
struct VertexShaderInput
{
float4 position : POSITION;
#ifdef NORMALS
float3 normal : NORMAL;
#endif
#ifdef UV
float2 texcoord : TEXCOORD0;
#endif
};
// Per-pixel color data passed through the pixel shader.
struct PixelShaderInput
{
float4 position : SV_POSITION;
float4 positionWS : TEXCOORD1;
float3 normalWS : TEXCOORD2;
#ifdef NORMALS
float3 normal : NORMAL;
#endif
float2 texcoord : TEXCOORD0;
};
PixelShaderInput main_vs(VertexShaderInput input)
{
PixelShaderInput output;
// Transform the vertex position into projected space.
float4 pos = mul(input.position, model);
#ifdef NORMALS
// If we have normals...
output.normal = normalize(mul(float4(input.normal.xyz, 0.0), model));
#endif
#ifdef UV
output.texcoord = input.texcoord;
#else
output.texcoord = float2(0.0f, 0.0f);
#endif
#ifdef HAS_NORMALS
#ifdef HAS_TANGENTS
vec3 normalW = normalize(vec3(u_ModelMatrix * vec4(a_Normal.xyz, 0.0)));
vec3 tangentW = normalize(vec3(u_ModelMatrix * vec4(a_Tangent.xyz, 0.0)));
vec3 bitangentW = cross(normalW, tangentW) * a_Tangent.w;
v_TBN = mat3(tangentW, bitangentW, normalW);
#else // HAS_TANGENTS != 1
v_Normal = normalize(vec3(u_ModelMatrix * vec4(a_Normal.xyz, 0.0)));
#endif
#endif
// Transform the vertex position into projected space.
pos = mul(pos, view);
pos = mul(pos, projection);
output.position = pos;
return output;
}
//
// This fragment shader defines a reference implementation for Physically Based Shading of
// a microfacet surface material defined by a glTF model.
//
// References:
// [1] Real Shading in Unreal Engine 4
// http://blog.selfshadow.com/publications/s2013-shading-course/karis/s2013_pbs_epic_notes_v2.pdf
// [2] Physically Based Shading at Disney
// http://blog.selfshadow.com/publications/s2012-shading-course/burley/s2012_pbs_disney_brdf_notes_v3.pdf
// [3] README.md - Environment Maps
// https://github.com/KhronosGroup/glTF-WebGL-PBR/#environment-maps
// [4] "An Inexpensive BRDF Model for Physically based Rendering" by Christophe Schlick
// https://www.cs.virginia.edu/~jdl/bib/appearance/analytic%20models/schlick94b.pdf
#define NORMALS
#define UV
#define HAS_NORMALS
// #define USE_IBL
#define USE_TEX_LOD
DECLARE_TEXTURE(baseColourTexture, 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);
cbuffer cbPerFrame : register(b0)
{
float3 lightDir;
float3 lightColour;
};
cbuffer cbPerObject : register(b1)
{
float normalScale;
float3 emissiveFactor;
float occlusionStrength;
float2 metallicRoughnessValues;
float4 baseColorFactor;
float3 camera;
// debugging flags used for shader output of intermediate PBR variables
float4 scaleDiffBaseMR;
float4 scaleFGDSpec;
float4 scaleIBLAmbient;
};
#ifdef HAS_NORMALS
#ifdef HAS_TANGENTS
varying mat3 v_TBN;
#else
#endif
#endif
// Encapsulate the various inputs used by the various functions in the shading equation
// We store values in this struct to simplify the integration of alternative implementations
// of the shading terms, outlined in the Readme.MD Appendix.
struct PBRInfo
{
float NdotL; // cos angle between normal and light direction
float NdotV; // cos angle between normal and view direction
float NdotH; // cos angle between normal and half vector
float LdotH; // cos angle between light direction and half vector
float VdotH; // cos angle between view direction and half vector
float perceptualRoughness; // roughness value, as authored by the model creator (input to shader)
float metalness; // metallic value at the surface
float3 reflectance0; // full reflectance color (normal incidence angle)
float3 reflectance90; // reflectance color at grazing angle
float alphaRoughness; // roughness mapped to a more linear change in the roughness (proposed by [2])
float3 diffuseColor; // color contribution from diffuse lighting
float3 specularColor; // color contribution from specular lighting
};
static const float M_PI = 3.141592653589793;
static const float c_MinRoughness = 0.04;
float4 SRGBtoLINEAR(float4 srgbIn)
{
#ifdef MANUAL_SRGB
#ifdef SRGB_FAST_APPROXIMATION
float3 linOut = pow(srgbIn.xyz,float3(2.2, 2.2, 2.2));
#else //SRGB_FAST_APPROXIMATION
float3 bLess = step(float3(0.04045, 0.04045, 0.04045), srgbIn.xyz);
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);
#endif //SRGB_FAST_APPROXIMATION
return float4(linOut,srgbIn.w);;
#else //MANUAL_SRGB
return srgbIn;
#endif //MANUAL_SRGB
}
// Find the normal for this fragment, pulling either from a predefined normal map
// or from the interpolated mesh normal and tangent attributes.
float3 getNormal(float3 position, float3 normal, float2 uv)
{
// Retrieve the tangent space matrix
#ifndef HAS_TANGENTS
float3 pos_dx = ddx(position);
float3 pos_dy = ddy(position);
float3 tex_dx = ddx(float3(uv, 0.0));
float3 tex_dy = ddy(float3(uv, 0.0));
float3 t = (tex_dy.y * pos_dx - tex_dx.y * pos_dy) / (tex_dx.x * tex_dy.y - tex_dy.x * tex_dx.y);
#ifdef HAS_NORMALS
float3 ng = normalize(normal);
#else
float3 ng = cross(pos_dx, pos_dy);
#endif
t = normalize(t - ng * dot(ng, t));
float3 b = normalize(cross(ng, t));
row_major float3x3 tbn = float3x3(t, b, ng);
#else // HAS_TANGENTS
mat3 tbn = v_TBN;
#endif
#ifdef HAS_NORMALMAP
float3 n = SAMPLE_TEXTURE(normalTexture, uv).rgb;
// Need to check the multiplication is equivalent..
n = normalize(mul(((2.0 * n - 1.0) * float3(normalScale, normalScale, 1.0)), tbn));
#else
float3 n = tbn[2].xyz;
#endif
return n;
}
#ifdef USE_IBL
// Calculation of the lighting contribution from an optional Image Based Light source.
// Precomputed Environment Maps are required uniform inputs and are computed as outlined in [1].
// See our README.md on Environment Maps [3] for additional discussion.
float3 getIBLContribution(PBRInfo pbrInputs, float3 n, float3 reflection)
{
float mipCount = 9.0; // resolution of 512x512
float lod = (pbrInputs.perceptualRoughness * mipCount);
// retrieve a scale and bias to F0. See [1], Figure 3
float2 val = float2(pbrInputs.NdotV, 1.0 - pbrInputs.perceptualRoughness);
float3 brdf = SRGBtoLINEAR(SAMPLE_TEXTURE(brdfLutTexture, val)).rgb;
float3 diffuseLight = SRGBtoLINEAR(SAMPLE_CUBEMAP(envDiffuseTexture, n)).rgb;
#ifdef USE_TEX_LOD
float4 reflectionWithLOD = float4(reflection, 0);
float3 specularLight = SRGBtoLINEAR(SAMPLE_CUBEMAP_LOD(envSpecularTexture, reflectionWithLOD)).rgb;
#else
float3 specularLight = SRGBtoLINEAR(SAMPLE_CUBEMAP(envSpecularTexture, reflection)).rgb;
#endif
float3 diffuse = diffuseLight * pbrInputs.diffuseColor;
float3 specular = specularLight * (pbrInputs.specularColor * brdf.x + brdf.y);
// For presentation, this allows us to disable IBL terms
diffuse *= scaleIBLAmbient.x;
specular *= scaleIBLAmbient.y;
return diffuse + specular;
}
#endif
// Basic Lambertian diffuse
// Implementation from Lambert's Photometria https://archive.org/details/lambertsphotome00lambgoog
// See also [1], Equation 1
float3 diffuse(PBRInfo pbrInputs)
{
return pbrInputs.diffuseColor / M_PI;
}
// The following equation models the Fresnel reflectance term of the spec equation (aka F())
// Implementation of fresnel from [4], Equation 15
float3 specularReflection(PBRInfo pbrInputs)
{
return pbrInputs.reflectance0 + (pbrInputs.reflectance90 - pbrInputs.reflectance0) * pow(clamp(1.0 - pbrInputs.VdotH, 0.0, 1.0), 5.0);
}
// This calculates the specular geometric attenuation (aka G()),
// where rougher material will reflect less light back to the viewer.
// This implementation is based on [1] Equation 4, and we adopt their modifications to
// alphaRoughness as input as originally proposed in [2].
float geometricOcclusion(PBRInfo pbrInputs)
{
float NdotL = pbrInputs.NdotL;
float NdotV = pbrInputs.NdotV;
float r = pbrInputs.alphaRoughness;
float attenuationL = 2.0 * NdotL / (NdotL + sqrt(r * r + (1.0 - r * r) * (NdotL * NdotL)));
float attenuationV = 2.0 * NdotV / (NdotV + sqrt(r * r + (1.0 - r * r) * (NdotV * NdotV)));
return attenuationL * attenuationV;
}
// The following equation(s) model the distribution of microfacet normals across the area being drawn (aka D())
// Implementation from "Average Irregularity Representation of a Roughened Surface for Ray Reflection" by T. S. Trowbridge, and K. P. Reitz
// Follows the distribution function recommended in the SIGGRAPH 2013 course notes from EPIC Games [1], Equation 3.
float microfacetDistribution(PBRInfo pbrInputs)
{
float roughnessSq = pbrInputs.alphaRoughness * pbrInputs.alphaRoughness;
float f = (pbrInputs.NdotH * roughnessSq - pbrInputs.NdotH) * pbrInputs.NdotH + 1.0;
return roughnessSq / (M_PI * f * f);
}
float4 main_ps(PixelShaderInput input) : SV_TARGET
{
// Metallic and Roughness material properties are packed together
// In glTF, these factors can be specified by fixed scalar values
// or from a metallic-roughness map
float perceptualRoughness = metallicRoughnessValues.y;
float metallic = metallicRoughnessValues.x;
#ifdef HAS_METALROUGHNESSMAP
// Roughness is stored in the 'g' channel, metallic is stored in the 'b' channel.
// This layout intentionally reserves the 'r' channel for (optional) occlusion map data
float4 mrSample = SAMPLE_TEXTURE(metallicRoughnessTexture, input.texcoord);
// Had to reverse the order of the channels here - TODO: investigate..
perceptualRoughness = mrSample.g * perceptualRoughness;
metallic = mrSample.b * metallic;
#endif
perceptualRoughness = clamp(perceptualRoughness, c_MinRoughness, 1.0);
metallic = clamp(metallic, 0.0, 1.0);
// Roughness is authored as perceptual roughness; as is convention,
// convert to material roughness by squaring the perceptual roughness [2].
float alphaRoughness = perceptualRoughness * perceptualRoughness;
// The albedo may be defined from a base texture or a flat color
#ifdef HAS_BASECOLORMAP
float4 baseColor = SRGBtoLINEAR(SAMPLE_TEXTURE(baseColourTexture, input.texcoord)) * baseColorFactor;
#else
float4 baseColor = baseColorFactor;
#endif
float3 f0 = float3(0.04, 0.04, 0.04);
float3 diffuseColor = baseColor.rgb * (float3(1.0, 1.0, 1.0) - f0);
diffuseColor *= 1.0 - metallic;
float3 specularColor = lerp(f0, baseColor.rgb, metallic);
// Compute reflectance.
float reflectance = max(max(specularColor.r, specularColor.g), specularColor.b);
// For typical incident reflectance range (between 4% to 100%) set the grazing reflectance to 100% for typical fresnel effect.
// For very low reflectance range on highly diffuse objects (below 4%), incrementally reduce grazing reflecance to 0%.
float reflectance90 = clamp(reflectance * 25.0, 0.0, 1.0);
float3 specularEnvironmentR0 = specularColor.rgb;
float3 specularEnvironmentR90 = float3(1.0, 1.0, 1.0) * reflectance90;
float3 n = getNormal(input.poswithoutw, input.normal, input.texcoord); // normal at surface point
float3 v = normalize(camera - input.poswithoutw); // Vector from surface point to camera
float3 l = normalize(lightDir); // Vector from surface point to light
float3 h = normalize(l + v); // Half vector between both l and v
float3 reflection = -normalize(reflect(v, n));
float NdotL = clamp(dot(n, l), 0.001, 1.0);
float NdotV = abs(dot(n, v)) + 0.001;
float NdotH = clamp(dot(n, h), 0.0, 1.0);
float LdotH = clamp(dot(l, h), 0.0, 1.0);
float VdotH = clamp(dot(v, h), 0.0, 1.0);
PBRInfo pbrInputs;
pbrInputs.NdotL = NdotL;
pbrInputs.NdotV = NdotV;
pbrInputs.NdotH = NdotH;
pbrInputs.LdotH = LdotH;
pbrInputs.VdotH = VdotH;
pbrInputs.perceptualRoughness = perceptualRoughness;
pbrInputs.metalness = metallic;
pbrInputs.reflectance0 = specularEnvironmentR0;
pbrInputs.reflectance90 = specularEnvironmentR90;
pbrInputs.alphaRoughness = alphaRoughness;
pbrInputs.diffuseColor = diffuseColor;
pbrInputs.specularColor = specularColor;
// Calculate the shading terms for the microfacet specular shading model
float3 F = specularReflection(pbrInputs);
float G = geometricOcclusion(pbrInputs);
float D = microfacetDistribution(pbrInputs);
// Calculation of analytical lighting contribution
float3 diffuseContrib = (1.0 - F) * diffuse(pbrInputs);
float3 specContrib = F * G * D / (4.0 * NdotL * NdotV);
float3 color = NdotL * lightColour * (diffuseContrib + specContrib);
// Calculate lighting contribution from image based lighting source (IBL)
#ifdef USE_IBL
color += getIBLContribution(pbrInputs, n, reflection);
#endif
// Apply optional PBR terms for additional (optional) shading
#ifdef HAS_OCCLUSIONMAP
float ao = SAMPLE_TEXTURE(occlusionTexture, input.texcoord).r;
color = lerp(color, color * ao, occlusionStrength);
#endif
#ifdef HAS_EMISSIVEMAP
float3 emissive = SRGBtoLINEAR(SAMPLE_TEXTURE(emissionTexture, input.texcoord)).rgb * emissiveFactor;
color += emissive;
#endif
// This section uses lerp to override final color for reference app visualization
// of various parameters in the lighting equation.
color = lerp(color, F, scaleFGDSpec.x);
color = lerp(color, float3(G, G, G), scaleFGDSpec.y);
color = lerp(color, float3(D, D, D), scaleFGDSpec.z);
color = lerp(color, specContrib, scaleFGDSpec.w);
color = lerp(color, diffuseContrib, scaleDiffBaseMR.x);
color = lerp(color, baseColor.rgb, scaleDiffBaseMR.y);
color = lerp(color, float3(metallic, metallic, metallic), scaleDiffBaseMR.z);
color = lerp(color, float3(perceptualRoughness, perceptualRoughness, perceptualRoughness), scaleDiffBaseMR.w);
//return float4(baseColor.xyz, 1.0);
return float4(color, 1.0);
}
Technique PBR
{
Pass pass1
{
VertexShader = compile vs_3_0 main_vs();
PixelShader = compile ps_3_0 main_ps();
}
}