protot/data/shaders/fs_ssao.glsl

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2018-04-05 12:39:30 +02:00
#version 150 core
in vec2 ioFragTexCoords;
out vec3 outColor;
uniform sampler2D uPositions;
uniform sampler2D uNormals;
uniform sampler2D uNoise;
uniform float uRadius;
uniform float uBias;
uniform int uSampleCount;
uniform vec3 uSamples[64];
uniform mat4 uProjection;
void main() {
vec2 noise_scale = textureSize(uPositions, 0) / 2.0;
vec3 position = texture(uPositions, ioFragTexCoords).xyz;
vec3 normal = normalize(texture(uNormals, ioFragTexCoords)).rgb;
vec3 random_vector = normalize(texture(uNoise, ioFragTexCoords * noise_scale).xyz);
vec3 tangent = normalize(random_vector - normal * dot(random_vector, normal));
vec3 bitangent = cross(normal, tangent);
mat3 TBN = mat3 (tangent, bitangent, normal);
float occlusion = 0.0;
for (int i = 0; i < uSampleCount; ++i) {
vec3 sample = TBN * uSamples[i];
sample = position + sample * uRadius;
vec4 offset = vec4(sample, 1.0);
offset = uProjection * offset;
offset.xyz /= offset.w;
offset.xyz = offset.xyz * 0.5 + 0.5;
float sample_depth = texture(uPositions, offset.xy).z;
float range_check = smoothstep(0.0, 1.0, uRadius / abs(position.z - sample_depth));
occlusion += (sample_depth >= sample.z + uBias ? 1.0 : 0.0) * range_check;
}
occlusion = 1.0 - (occlusion / uSampleCount);
outColor = vec3(occlusion);
}