Bliss-Shader/shaders/lib/specular.glsl

299 lines
10 KiB
GLSL

uniform int framemod8;
const vec2[8] offsets = vec2[8](vec2(1./8.,-3./8.),
vec2(-1.,3.)/8.,
vec2(5.0,1.)/8.,
vec2(-3,-5.)/8.,
vec2(-5.,5.)/8.,
vec2(-7.,-1.)/8.,
vec2(3,7.)/8.,
vec2(7.,-7.)/8.);
vec3 lerp(vec3 X, vec3 Y, float A){
return X * (1.0 - A) + Y * A;
}
float lerp(float X, float Y, float A){
return X * (1.0 - A) + Y * A;
}
float square(float x){
return x*x;
}
vec3 toClipSpace3(vec3 viewSpacePosition) {
return projMAD(gbufferProjection, viewSpacePosition) / -viewSpacePosition.z * 0.5 + 0.5;
}
float invLinZ (float lindepth){
return -((2.0*near/lindepth)-far-near)/(far-near);
}
float linZ(float depth) {
return (2.0 * near) / (far + near - depth * (far - near));
// l = (2*n)/(f+n-d(f-n))
// f+n-d(f-n) = 2n/l
// -d(f-n) = ((2n/l)-f-n)
// d = -((2n/l)-f-n)/(f-n)
}
void frisvad(in vec3 n, out vec3 f, out vec3 r){
if(n.z < -0.9) {
f = vec3(0.,-1,0);
r = vec3(-1, 0, 0);
} else {
float a = 1./(1.+n.z);
float b = -n.x*n.y*a;
f = vec3(1. - n.x*n.x*a, b, -n.x) ;
r = vec3(b, 1. - n.y*n.y*a , -n.y);
}
}
mat3 CoordBase(vec3 n){
vec3 x,y;
frisvad(n,x,y);
return mat3(x,y,n);
}
vec2 R2_Sample(int n){
vec2 alpha = vec2(0.75487765, 0.56984026);
return fract(alpha * n);
}
vec3 rayTraceSpeculars(vec3 dir, vec3 position, float dither, float quality, bool hand, inout float reflectLength){
vec3 clipPosition = toClipSpace3(position);
float rayLength = ((position.z + dir.z * far*sqrt(3.)) > -near) ?
(-near -position.z) / dir.z : far*sqrt(3.);
vec3 direction = normalize(toClipSpace3(position+dir*rayLength)-clipPosition); //convert to clip space
direction.xy = normalize(direction.xy);
//get at which length the ray intersects with the edge of the screen
vec3 maxLengths = (step(0.0,direction)-clipPosition) / direction;
float mult = min(min(maxLengths.x,maxLengths.y),maxLengths.z);
vec3 stepv = direction * mult / quality*vec3(RENDER_SCALE,1.0);
vec3 spos = clipPosition*vec3(RENDER_SCALE,1.0) + stepv*dither;
float minZ = spos.z;
float maxZ = spos.z;
spos.xy += TAA_Offset*texelSize*0.5/RENDER_SCALE;
float depthcancleoffset = pow(1.0-(quality/reflection_quality),1.0);
float dist = 1.0 + clamp(position.z*position.z/50.0,0.0,2.0); // shrink sample size as distance increases
for (int i = 0; i <= int(quality); i++) {
// float sp = invLinZ(sqrt(texelFetch2D(colortex4,ivec2(spos.xy/texelSize/4.0),0).a/65000.0));
// if(sp <= max(maxZ,minZ) && sp >= min(maxZ,minZ) ) return vec3(spos.xy/RENDER_SCALE,sp);
// spos += stepv;
// //small bias
// float biasamount = (0.0002 + 0.0015*pow(depthcancleoffset,5) ) / dist;
// if(hand) biasamount = 0.00035;
// minZ = maxZ-biasamount / ld(spos.z);
// maxZ += stepv.z;
float sp = invLinZ(sqrt(texelFetch2D(colortex4,ivec2(spos.xy/texelSize/4.0),0).a/65000.0));
float currZ = linZ(spos.z);
float nextZ = linZ(sp);
// if(nextZ < currZ) {
if(abs(nextZ-currZ)/currZ < 0.15 && sp <= max(minZ,maxZ) && sp >= min(minZ,maxZ)) return vec3(spos.xy/RENDER_SCALE,sp);
// }
float biasamount = 0.005;
minZ = maxZ-biasamount / linZ(spos.z);
maxZ += stepv.z;
spos += stepv;
reflectLength += 1.0 / quality; // for shit
}
return vec3(1.1);
}
float fma(float a,float b,float c){
return a * b + c;
}
//// thank you Zombye | the paper: https://ggx-research.github.io/publication/2023/06/09/publication-ggx.html
vec3 SampleVNDFGGX(
vec3 viewerDirection, // Direction pointing towards the viewer, oriented such that +Z corresponds to the surface normal
vec2 alpha, // Roughness parameter along X and Y of the distribution
float xy // Pair of uniformly distributed numbers in [0, 1)
) {
// alpha *= alpha;
// Transform viewer direction to the hemisphere configuration
viewerDirection = normalize(vec3(alpha * viewerDirection.xy, viewerDirection.z));
// Sample a reflection direction off the hemisphere
const float tau = 6.2831853; // 2 * pi
float phi = tau * xy;
float cosTheta = fma(1.0 - xy, 1.0 + viewerDirection.z, -viewerDirection.z) ;
float sinTheta = sqrt(clamp(1.0 - cosTheta * cosTheta, 0.0, 1.0));
// xonk note, i dont know what im doing but this kinda does what i want so whatever
float attemptTailClamp = clamp(sinTheta,max(cosTheta-0.25,0), cosTheta);
float attemptTailClamp2 = clamp(cosTheta,max(sinTheta-0.25,0), sinTheta);
vec3 reflected = vec3(vec2(cos(phi), sin(phi)) * attemptTailClamp2, attemptTailClamp);
// vec3 reflected = vec3(vec2(cos(phi), sin(phi)) * sinTheta, cosTheta);
// Evaluate halfway direction
// This gives the normal on the hemisphere
vec3 halfway = reflected + viewerDirection;
// Transform the halfway direction back to hemiellispoid configuation
// This gives the final sampled normal
return normalize(vec3(alpha * halfway.xy, halfway.z));
}
float GGX(vec3 n, vec3 v, vec3 l, float r, float f0) {
r = max(pow(r,2.5), 0.0001);
vec3 h = l + v;
float hn = inversesqrt(dot(h, h));
float dotLH = clamp(dot(h,l)*hn,0.,1.);
float dotNH = clamp(dot(h,n)*hn,0.,1.) ;
float dotNL = clamp(dot(n,l),0.,1.);
float dotNHsq = dotNH*dotNH;
float denom = dotNHsq * r - dotNHsq + 1.;
float D = r / (3.141592653589793 * denom * denom);
float F = f0 + (1. - f0) * exp2((-5.55473*dotLH-6.98316)*dotLH);
float k2 = .25 * r;
return dotNL * D * F / (dotLH*dotLH*(1.0-k2)+k2);
}
void DoSpecularReflections(
inout vec3 Output,
vec3 FragPos, // toScreenspace(vec3(screenUV, depth)
vec3 WorldPos,
vec3 LightPos, // should be in world space
vec2 Noise, // x = bluenoise z = interleaved gradient noise
vec3 Normal, // normals in world space
float Roughness, // red channel of specular texture _S
float F0, // green channel of specular texture _S
vec3 Albedo,
vec3 Diffuse, // should contain the light color and NdotL. and maybe shadows.
float Lightmap, // in anything other than world0, this should be 1.0;
bool Hand // mask for the hand
){
vec3 Final_Reflection = Output;
vec3 Background_Reflection = Output;
vec3 Lightsource_Reflection = vec3(0.0);
vec4 SS_Reflections = vec4(0.0);
Lightmap = clamp((Lightmap-0.8)*7.0, 0.0,1.0);
Roughness = 1.0 - Roughness; Roughness *= Roughness;
F0 = F0 == 0.0 ? 0.02 : F0;
// Roughness = 0.0;
// F0 = 0.9;
mat3 Basis = CoordBase(Normal);
vec3 ViewDir = -WorldPos*Basis;
#ifdef Rough_reflections
vec3 SamplePoints = SampleVNDFGGX(ViewDir, vec2(Roughness), Noise.x);
if(Hand) SamplePoints = vec3(0.0,0.0,1.0);
#else
vec3 SamplePoints = vec3(0.0,0.0,1.0);
#endif
vec3 Ln = reflect(-ViewDir, SamplePoints);
vec3 L = Basis * Ln;
float Fresnel = pow(clamp(1.0 + dot(-Ln, SamplePoints),0.0,1.0), 5.0); // Schlick's approximation
float RayContribution = lerp(F0, 1.0, Fresnel); // ensure that when the angle is 0 that the correct F0 is used.
#ifdef Rough_reflections
if(Hand) RayContribution = RayContribution * pow(1.0-Roughness,F0 > 229.5/255.0 ? 1.0 : 3.0);
#else
RayContribution = RayContribution * pow(1.0-Roughness,3.0);
#endif
bool hasReflections = Roughness_Threshold == 1.0 ? true : F0 * (1.0 - Roughness * Roughness_Threshold) > 0.01;
// mulitply all reflections by the albedo if it is a metal.
// vec3 Metals = F0 > 229.5/255.0 ? lerp(normalize(Albedo+1e-7) * (dot(Albedo,vec3(0.21, 0.72, 0.07)) * 0.7 + 0.3), vec3(1.0), Fresnel * pow(1.0-Roughness,25.0)) : vec3(1.0);
vec3 Metals = F0 > 229.5/255.0 ? normalize(Albedo+1e-7) * (dot(Albedo,vec3(0.21, 0.72, 0.07)) * 0.7 + 0.3) : vec3(1.0);
// vec3 Metals = F0 > 229.5/255.0 ? Albedo : vec3(1.0);
// --------------- BACKGROUND REFLECTIONS
// apply background reflections to the final color. make sure it does not exist based on the lightmap
#ifdef Sky_reflection
#ifdef OVERWORLD_SHADER
if(hasReflections) Background_Reflection = (skyCloudsFromTex(L, colortex4).rgb / 30.0) * Metals ;
#else
if(hasReflections) Background_Reflection = (skyCloudsFromTexLOD2(L, colortex4, sqrt(Roughness) * 6.0).rgb / 30.0) * Metals;
#endif
// take fresnel and lightmap levels into account and write to the final color
Final_Reflection = lerp(Output, Background_Reflection, Lightmap * RayContribution);
#endif
// --------------- SCREENSPACE REFLECTIONS
// apply screenspace reflections to the final color and mask out background reflections.
#ifdef Screen_Space_Reflections
if(hasReflections){
#ifdef Dynamic_SSR_quality
float SSR_Quality = lerp(reflection_quality, 6.0, RayContribution); // Scale quality with ray contribution
#else
float SSR_Quality = reflection_quality;
#endif
float reflectLength = 0.0;
vec3 RaytracePos = rayTraceSpeculars(mat3(gbufferModelView) * L, FragPos, Noise.y, float(SSR_Quality), Hand, reflectLength);
float LOD = clamp(pow(reflectLength, pow(1.0-sqrt(Roughness),5.0) * 3.0) * 6.0, 0.0, 6.0); // use higher LOD as the reflection goes on, to blur it. this helps denoise a little.
if(Roughness <= 0.0) LOD = 0.0;
if (RaytracePos.z < 1.0){
vec3 previousPosition = mat3(gbufferModelViewInverse) * toScreenSpace(RaytracePos) + gbufferModelViewInverse[3].xyz + cameraPosition-previousCameraPosition;
previousPosition = mat3(gbufferPreviousModelView) * previousPosition + gbufferPreviousModelView[3].xyz;
previousPosition.xy = projMAD(gbufferPreviousProjection, previousPosition).xy / -previousPosition.z * 0.5 + 0.5;
if (previousPosition.x > 0.0 && previousPosition.y > 0.0 && previousPosition.x < 1.0 && previousPosition.x < 1.0) {
SS_Reflections.a = 1.0;
SS_Reflections.rgb = texture2DLod(colortex5, previousPosition.xy, LOD).rgb * Metals;
}
}
// make sure it takes the fresnel into account for SSR.
SS_Reflections.rgb = lerp(Output, SS_Reflections.rgb, RayContribution);
// occlude the background with the SSR and write to the final color.
Final_Reflection = lerp(Final_Reflection, SS_Reflections.rgb, SS_Reflections.a);
}
#endif
// Final_Reflection = mix(mix(Output,Background_Reflection,Lightmap), SS_Reflections.rgb, SS_Reflections.a) * RayContribution;
// --------------- LIGHTSOURCE REFLECTIONS
// slap the main lightsource reflections to the final color.
#ifdef LIGHTSOURCE_REFLECTION
Lightsource_Reflection = Diffuse * GGX(Normal, -WorldPos, LightPos, Roughness, F0) * Metals;
Final_Reflection += Lightsource_Reflection * Sun_specular_Strength ;
#endif
Output = Final_Reflection;
}