75 lines
2.3 KiB
GLSL
75 lines
2.3 KiB
GLSL
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#version 430 core
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const float DIFFUSE_INTENSITY = 0.6;
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const float MAX_RENDER_DISTANCE = 16.0;
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float surfaceRoughness;
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float metalnessValue;
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uniform vec3 primaryColor;
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uniform sampler2D colorTexture;
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uniform sampler2D normalMap;
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uniform sampler2D metalnessMap;
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uniform sampler2D roughnessMap;
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in vec3 worldPos;
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in vec2 vecTex;
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in vec3 viewDirTS;
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in vec3 lightDirTS;
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in float distanceToCamera;
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out vec4 fragmentColor;
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float calculateMicrofacetDistribution(float roughness, vec3 normal, vec3 halfVector) {
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float NdotH = max(0.0, dot(normal, halfVector));
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float roughnessSq = roughness * roughness;
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float denom = 3.14159 * pow(NdotH * NdotH * (roughnessSq - 1.0) + 1.0, 2.0);
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return roughnessSq / denom;
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}
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float calculateGeometryTerm(float roughness, float NdotV, float NdotL) {
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float k = pow(roughness + 1.0, 2.0) / 8.0;
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return NdotV / (NdotV * (1.0 - k) + k) * NdotL / (NdotL * (1.0 - k) + k);
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}
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vec3 calculateFresnelTerm(float metallic, vec3 F0, float VdotH) {
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return F0 + (1.0 - F0) * pow(1.0 - VdotH, 5.0);
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}
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void main() {
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vec3 textureColor = texture(colorTexture, vecTex).xyz;
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metalnessValue = texture(metalnessMap, vecTex).r;
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surfaceRoughness = texture(roughnessMap, vecTex).r;
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vec3 normal = texture(normalMap, vecTex).xyz;
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normal = normalize(normal);
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vec3 viewDir = normalize(viewDirTS);
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vec3 lightDir = normalize(lightDirTS);
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vec3 halfVector = normalize(lightDir + viewDir);
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float microfacetDistribution = calculateMicrofacetDistribution(surfaceRoughness, normal, halfVector);
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float NdotV = max(0.0, dot(normal, viewDir));
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float NdotL = max(dot(normal, lightDir), 0.0000001);
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float geometryTerm = calculateGeometryTerm(surfaceRoughness, NdotV, NdotL);
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vec3 F0 = mix(vec3(0.04), vec3(1.0), vec3(metalnessValue));
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float VdotH = max(0.00001, dot(viewDir, halfVector));
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vec3 fresnelTerm = calculateFresnelTerm(metalnessValue, F0, VdotH);
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vec3 specular = (microfacetDistribution * geometryTerm * fresnelTerm) / (4.0 * NdotL * NdotV + 0.00001);
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vec3 diffuseReflectance = vec3(1.0) - fresnelTerm;
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vec3 BRDF = diffuseReflectance * (textureColor / 3.1458493) + specular;
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if (distanceToCamera > MAX_RENDER_DISTANCE) {
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discard;
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}
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float diffuse = max(0.0001, dot(normal, lightDir));
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fragmentColor = vec4(BRDF * (DIFFUSE_INTENSITY + diffuse) * 1.5, 1.0);
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}
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