Files
OrcaSlicer/resources/shaders/140/ssao.fs
2026-05-18 17:50:01 -03:00

99 lines
3.4 KiB
GLSL

#version 140
/**
* SSAO Shader - GLSL 140 version with highlight protection
* Preserves brightness on upward-facing surfaces for better visual quality
*/
uniform sampler2D color_texture;
uniform sampler2D depth_texture;
uniform sampler2D normal_texture;
uniform float z_near;
uniform float z_far;
in vec2 tex_coord;
out vec4 frag_color;
float linearize_depth(float depth)
{
float z = depth * 2.0 - 1.0;
return (2.0 * z_near * z_far) / (z_far + z_near - z * (z_far - z_near));
}
void main()
{
ivec2 pixel = ivec2(gl_FragCoord.xy);
float center_depth = linearize_depth(texelFetch(depth_texture, pixel, 0).r);
// Sample normal buffer (stored as RGB in 0-1 range, convert to -1 to 1)
vec3 normal_center = texelFetch(normal_texture, pixel, 0).rgb * 2.0 - 1.0;
normal_center = normalize(normal_center);
// Calculate upward-facing factor
// Assumes Z-up coordinate system (typical for 3D printing)
float up_factor = clamp(normal_center.z * 1.5, 0.0, 1.0); // Boosted for better response
// Alternative if using Y-up: float up_factor = clamp(normal_center.y * 1.5, 0.0, 1.0);
// Adaptive radius in pixel space
int radius = int(mix(2.0, 5.0, center_depth / z_far));
// Optimized sampling pattern
const ivec2 offsets[12] = ivec2[](
ivec2(1, 0), ivec2(-1, 0), ivec2(0, 1), ivec2(0, -1),
ivec2(1, 1), ivec2(-1, 1), ivec2(1, -1), ivec2(-1, -1),
ivec2(2, 0), ivec2(-2, 0), ivec2(0, 2), ivec2(0, -2)
);
float occlusion = 0.0;
int valid_samples = 0;
for (int i = 0; i < 12; i++) {
ivec2 sample_pixel = pixel + offsets[i] * radius;
if (sample_pixel.x < 0 || sample_pixel.y < 0)
continue;
float sample_depth = linearize_depth(texelFetch(depth_texture, sample_pixel, 0).r);
// Sample normal at neighbor
vec3 normal_sample = texelFetch(normal_texture, sample_pixel, 0).rgb * 2.0 - 1.0;
// Direction from center to sample in screen space
vec2 dir_2d = normalize(vec2(sample_pixel - pixel));
// Reduce occlusion when normals are similar (planar surfaces)
float normal_similarity = dot(normal_center, normal_sample);
float planar_factor = smoothstep(0.7, 0.95, normal_similarity);
float depth_diff = max(0.0, center_depth - sample_depth);
float threshold = 0.02 * (0.5 + center_depth / z_far);
float contribution = smoothstep(0.001, threshold, depth_diff);
// Reduce contribution on planar surfaces and top areas
float top_factor = 1.0 - up_factor * 0.6; // 60% less occlusion on tops
contribution *= (1.0 - planar_factor * 0.5) * top_factor;
occlusion += contribution;
valid_samples++;
}
if (valid_samples > 0) {
float ao_factor = 1.0 - (occlusion / float(valid_samples)) * 0.45;
// Brighter minimum for top surfaces
float ao_min = mix(0.50, 0.75, up_factor);
ao_factor = clamp(ao_factor, ao_min, 1.0);
// Additional brightness boost for upward-facing surfaces
float brightness_boost = 1.0 + up_factor * 0.2;
ao_factor = pow(ao_factor, 1.1) * brightness_boost;
occlusion = clamp(ao_factor, 0.45, 1.05);
} else {
occlusion = 1.0;
}
vec3 color = texture(color_texture, tex_coord).rgb;
frag_color = vec4(color * occlusion, 1.0);
}