engine/bin/data/shaders/gltf/baking/bake.frag.glsl
2021-04-15 00:00:00 -05:00

267 lines
7.4 KiB
GLSL

#version 450
layout (constant_id = 0) const uint TEXTURES = 1;
layout (binding = 0) uniform sampler2D samplerTextures[TEXTURES];
struct Material {
vec4 colorBase;
vec4 colorEmissive;
float factorMetallic;
float factorRoughness;
float factorOcclusion;
float factorAlphaCutoff;
int indexAlbedo;
int indexNormal;
int indexEmissive;
int indexOcclusion;
int indexMetallicRoughness;
int indexAtlas;
int indexLightmap;
int modeAlpha;
};
struct Texture {
int index;
int samp;
int remap;
float blend;
vec4 lerp;
};
struct Light {
vec3 position;
float radius;
vec3 color;
float power;
int type;
int mapIndex;
float depthBias;
float padding;
mat4 view;
mat4 projection;
};
layout (std140, binding = 3) readonly buffer Materials {
Material materials[];
};
layout (std140, binding = 4) readonly buffer Textures {
Texture textures[];
};
layout (std140, binding = 5) readonly buffer Lights {
Light lights[];
};
layout (location = 0) in vec2 inUv;
layout (location = 1) in vec4 inColor;
layout (location = 2) in vec3 inNormal;
layout (location = 3) in mat3 inTBN;
layout (location = 6) in vec3 inPosition;
layout (location = 7) flat in ivec4 inId;
layout (location = 0) out vec4 outAlbedo;
vec2 poissonDisk[16] = vec2[](
vec2( -0.94201624, -0.39906216 ),
vec2( 0.94558609, -0.76890725 ),
vec2( -0.094184101, -0.92938870 ),
vec2( 0.34495938, 0.29387760 ),
vec2( -0.91588581, 0.45771432 ),
vec2( -0.81544232, -0.87912464 ),
vec2( -0.38277543, 0.27676845 ),
vec2( 0.97484398, 0.75648379 ),
vec2( 0.44323325, -0.97511554 ),
vec2( 0.53742981, -0.47373420 ),
vec2( -0.26496911, -0.41893023 ),
vec2( 0.79197514, 0.19090188 ),
vec2( -0.24188840, 0.99706507 ),
vec2( -0.81409955, 0.91437590 ),
vec2( 0.19984126, 0.78641367 ),
vec2( 0.14383161, -0.14100790 )
);
float random(vec3 seed, int i){
vec4 seed4 = vec4(seed,i);
float dot_product = dot(seed4, vec4(12.9898,78.233,45.164,94.673));
return fract(sin(dot_product) * 43758.5453);
}
float shadowFactor( vec3 position, Light light, uint shadowMap, float def ) {
vec4 positionClip = light.projection * light.view * vec4(position, 1.0);
positionClip.xyz /= positionClip.w;
if ( positionClip.x < -1 || positionClip.x >= 1 ) return def;
if ( positionClip.y < -1 || positionClip.y >= 1 ) return def;
if ( positionClip.z <= 0 || positionClip.z >= 1 ) return def;
float factor = 1.0;
// spot light
if ( light.type == 2 || light.type == 3 ) {
float dist = length( positionClip.xy );
if ( dist > 0.5 ) return def;
// spot light with attenuation
if ( light.type == 3 ) {
factor = 1.0 - (pow(dist * 2,2.0));
}
}
vec2 uv = positionClip.xy * 0.5 + 0.5;
float bias = light.depthBias;
float eyeDepth = positionClip.z;
int samples = 16;
if ( samples <= 1 ) {
return eyeDepth < texture(samplerTextures[shadowMap], uv).r - bias ? 0.0 : factor;
}
for ( int i = 0; i < samples; ++i ) {
int index = int( float(samples) * random(floor(position * 1000.0), i)) % samples;
float lightDepth = texture(samplerTextures[shadowMap], uv + poissonDisk[index] / 700.0 ).r;
if ( eyeDepth < lightDepth - bias ) factor -= 1.0 / samples;
}
return factor;
}
float wrap( float i ) {
return fract(i);
}
vec2 wrap( vec2 uv ) {
return vec2( wrap( uv.x ), wrap( uv.y ) );
}
float mipLevel( in vec2 uv ) {
vec2 dx_vtc = dFdx(uv);
vec2 dy_vtc = dFdy(uv);
return 0.5 * log2(max(dot(dx_vtc, dx_vtc), dot(dy_vtc, dy_vtc)));
}
bool validTextureIndex( int textureIndex ) {
return 0 <= textureIndex && textureIndex < textures.length();
}
const float PI = 3.14159265359;
float DistributionGGX(vec3 N, vec3 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(vec3 N, vec3 V, vec3 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;
}
vec3 fresnelSchlick(float cosTheta, vec3 F0) {
return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
}
void pbr( Light light, vec3 albedo, float metallic, float roughness, vec3 normal, vec3 position, inout vec3 i ) {
vec3 F0 = vec3(0.04);
F0 = mix(F0, albedo, metallic);
vec3 N = normalize(normal);
vec3 L = light.position.xyz - position;
float dist = length(L);
L = normalize(L);
vec3 V = normalize(-position);
vec3 H = normalize(V + L);
float NdotL = max(dot(N, L), 0.0);
float NdotV = max(dot(N, V), 0.0);
float attenuation = light.power / (dist * dist);
vec3 radiance = light.color.rgb * attenuation;
// cook-torrance brdf
float NDF = DistributionGGX(N, H, roughness);
float G = GeometrySmith(N, V, L, roughness);
vec3 F = fresnelSchlick(max(dot(H, V), 0.0), F0);
vec3 kD = vec3(1.0) - F;
kD *= 1.0 - metallic;
vec3 numerator = NDF * G * F;
float denominator = 4.0 * NdotV * NdotL;
vec3 specular = numerator / max(denominator, 0.001);
// add to outgoing radiance Lo
// ignore specular
i += (kD * albedo / PI ) * radiance * NdotL;
}
void main() {
float mip = mipLevel(inUv.xy);
vec2 uv = wrap(inUv.xy);
vec4 C = vec4(1, 1, 1, 1);
vec3 P = inPosition;
vec3 N = normalize( inNormal );
int materialId = int(inId.y);
Material material = materials[materialId];
float M = material.factorMetallic;
float R = material.factorRoughness;
float AO = material.factorOcclusion;
#if 0
// sample albedo
bool useAtlas = validTextureIndex( material.indexAtlas );
Texture textureAtlas;
if ( useAtlas ) textureAtlas = textures[material.indexAtlas];
if ( !validTextureIndex( material.indexAlbedo ) ) discard;
{
Texture t = textures[material.indexAlbedo];
C = textureLod( samplerTextures[(useAtlas) ? textureAtlas.index : t.index], (useAtlas) ? mix( t.lerp.xy, t.lerp.zw, uv ) : uv, mip );
// alpha mode OPAQUE
if ( material.modeAlpha == 0 ) {
C.a = 1;
// alpha mode BLEND
} else if ( material.modeAlpha == 1 ) {
// alpha mode MASK
} else if ( material.modeAlpha == 2 ) {
if ( C.a < abs(material.factorAlphaCutoff) ) discard;
C.a = 1;
}
if ( C.a == 0 ) discard;
}
// sample normal
if ( validTextureIndex( material.indexNormal ) ) {
Texture t = textures[material.indexNormal];
N = inTBN * normalize( textureLod( samplerTextures[(useAtlas)?textureAtlas.index:t.index], ( useAtlas ) ? mix( t.lerp.xy, t.lerp.zw, uv ) : uv, mip ).xyz * 2.0 - vec3(1.0));
}
#endif
C = vec4(1);
bool lit = false;
vec3 fragColor = vec3(0);
for ( uint i = 0; i < lights.length(); ++i ) {
Light light = lights[i];
if ( light.power <= 0.001 ) continue;
if ( 0 <= light.mapIndex ) {
float factor = shadowFactor( P, light, light.mapIndex, 0.0 );
light.power *= factor;
}
if ( light.power <= 0.0001 ) continue;
pbr( light, C.rgb, M, R, N, P, fragColor );
}
outAlbedo = vec4(fragColor, 1);
}