diff options
Diffstat (limited to 'modules/lightmapper_rd/lm_compute.glsl')
| -rw-r--r-- | modules/lightmapper_rd/lm_compute.glsl | 73 |
1 files changed, 49 insertions, 24 deletions
diff --git a/modules/lightmapper_rd/lm_compute.glsl b/modules/lightmapper_rd/lm_compute.glsl index 25b334c5eb..7bb8346c47 100644 --- a/modules/lightmapper_rd/lm_compute.glsl +++ b/modules/lightmapper_rd/lm_compute.glsl @@ -94,13 +94,14 @@ params; //check it, but also return distance and barycentric coords (for uv lookup) bool ray_hits_triangle(vec3 from, vec3 dir, float max_dist, vec3 p0, vec3 p1, vec3 p2, out float r_distance, out vec3 r_barycentric) { + const float EPSILON = 0.00001; const vec3 e0 = p1 - p0; const vec3 e1 = p0 - p2; vec3 triangle_normal = cross(e1, e0); float n_dot_dir = dot(triangle_normal, dir); - if (abs(n_dot_dir) < 0.01) { + if (abs(n_dot_dir) < EPSILON) { return false; } @@ -148,7 +149,7 @@ uint trace_ray(vec3 p_from, vec3 p_to ivec3 icell = ivec3(from_cell); ivec3 iendcell = ivec3(to_cell); vec3 dir_cell = normalize(rel_cell); - vec3 delta = abs(1.0 / dir_cell); //vec3(length(rel_cell)) / rel_cell); + vec3 delta = min(abs(1.0 / dir_cell), params.grid_size); // use params.grid_size as max to prevent infinity values ivec3 step = ivec3(sign(rel_cell)); vec3 side = (sign(rel_cell) * (vec3(icell) - from_cell) + (sign(rel_cell) * 0.5) + 0.5) * delta; @@ -234,19 +235,39 @@ uint trace_ray(vec3 p_from, vec3 p_to return RAY_MISS; } +// https://www.reedbeta.com/blog/hash-functions-for-gpu-rendering/ +uint hash(uint value) { + uint state = value * 747796405u + 2891336453u; + uint word = ((state >> ((state >> 28u) + 4u)) ^ state) * 277803737u; + return (word >> 22u) ^ word; +} + +uint random_seed(ivec3 seed) { + return hash(seed.x ^ hash(seed.y ^ hash(seed.z))); +} + +// generates a random value in range [0.0, 1.0) +float randomize(inout uint value) { + value = hash(value); + return float(value / 4294967296.0); +} + const float PI = 3.14159265f; -const float GOLDEN_ANGLE = PI * (3.0 - sqrt(5.0)); - -vec3 vogel_hemisphere(uint p_index, uint p_count, float p_offset) { - float r = sqrt(float(p_index) + 0.5f) / sqrt(float(p_count)); - float theta = float(p_index) * GOLDEN_ANGLE + p_offset; - float y = cos(r * PI * 0.5); - float l = sin(r * PI * 0.5); - return vec3(l * cos(theta), l * sin(theta), y); + +// http://www.realtimerendering.com/raytracinggems/unofficial_RayTracingGems_v1.4.pdf (chapter 15) +vec3 generate_hemisphere_uniform_direction(inout uint noise) { + float noise1 = randomize(noise); + float noise2 = randomize(noise) * 2.0 * PI; + + float factor = sqrt(1 - (noise1 * noise1)); + return vec3(factor * cos(noise2), factor * sin(noise2), noise1); } -float quick_hash(vec2 pos) { - return fract(sin(dot(pos * 19.19, vec2(49.5791, 97.413))) * 49831.189237); +vec3 generate_hemisphere_cosine_weighted_direction(inout uint noise) { + float noise1 = randomize(noise); + float noise2 = randomize(noise) * 2.0 * PI; + + return vec3(sqrt(noise1) * cos(noise2), sqrt(noise1) * sin(noise2), sqrt(1.0 - noise1)); } float get_omni_attenuation(float distance, float inv_range, float decay) { @@ -403,8 +424,9 @@ void main() { #endif vec3 light_average = vec3(0.0); float active_rays = 0.0; + uint noise = random_seed(ivec3(params.ray_from, atlas_pos)); for (uint i = params.ray_from; i < params.ray_to; i++) { - vec3 ray_dir = normal_mat * vogel_hemisphere(i, params.ray_count, quick_hash(vec2(atlas_pos))); + vec3 ray_dir = normal_mat * generate_hemisphere_cosine_weighted_direction(noise); uint tidx; vec3 barycentric; @@ -420,20 +442,22 @@ void main() { light = textureLod(sampler2DArray(source_light, linear_sampler), uvw, 0.0).rgb; active_rays += 1.0; - } else if (trace_result == RAY_MISS && params.env_transform[0][3] == 0.0) { // Use env_transform[0][3] to indicate when we are computing the first bounce - // Did not hit a triangle, reach out for the sky - vec3 sky_dir = normalize(mat3(params.env_transform) * ray_dir); + } else if (trace_result == RAY_MISS) { + if (params.env_transform[0][3] == 0.0) { // Use env_transform[0][3] to indicate when we are computing the first bounce + // Did not hit a triangle, reach out for the sky + vec3 sky_dir = normalize(mat3(params.env_transform) * ray_dir); - vec2 st = vec2( - atan(sky_dir.x, sky_dir.z), - acos(sky_dir.y)); + vec2 st = vec2( + atan(sky_dir.x, sky_dir.z), + acos(sky_dir.y)); - if (st.x < 0.0) - st.x += PI * 2.0; + if (st.x < 0.0) + st.x += PI * 2.0; - st /= vec2(PI * 2.0, PI); + st /= vec2(PI * 2.0, PI); - light = textureLod(sampler2D(environment, linear_sampler), st, 0.0).rgb; + light = textureLod(sampler2D(environment, linear_sampler), st, 0.0).rgb; + } active_rays += 1.0; } @@ -547,8 +571,9 @@ void main() { vec4(0.0), vec4(0.0)); + uint noise = random_seed(ivec3(params.ray_from, probe_index, 49502741 /* some prime */)); for (uint i = params.ray_from; i < params.ray_to; i++) { - vec3 ray_dir = vogel_hemisphere(i, params.ray_count, quick_hash(vec2(float(probe_index), 0.0))); + vec3 ray_dir = generate_hemisphere_uniform_direction(noise); if (bool(i & 1)) { //throw to both sides, so alternate them ray_dir.z *= -1.0; |