diff options
| author | snowapril <sinjihng@gmail.com> | 2022-03-14 09:32:06 +0900 |
|---|---|---|
| committer | snowapril <sinjihng@gmail.com> | 2022-03-14 13:25:05 +0900 |
| commit | b6f72f2b4adbd1c98925656d0bcd8f97629cceac (patch) | |
| tree | 64eee1b9e81de5a4e9fda4cf40e5732489b1872f /servers/rendering/renderer_rd | |
| parent | 7a454842d4bb2c5f96a986df21a97888e1649887 (diff) | |
Fix D_GGX code which can cause divide-by-zero val
When given roughness is lower than 0.01, d value in original code will
be zero. This can make last return value as NAN because of
divide-by-zero. This is well addressed in issue #56373.
Modified code is referenced on D_GGX function of google/filament
(https://github.com/google/filament/blob/main/shaders/src/brdf.fs#L54-L79)
Signed-off-by: snowapril <sinjihng@gmail.com>
Diffstat (limited to 'servers/rendering/renderer_rd')
| -rw-r--r-- | servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl index 1c9b08b6d3..bd1c2b5758 100644 --- a/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl +++ b/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl @@ -1,9 +1,9 @@ // Functions related to lighting float D_GGX(float cos_theta_m, float alpha) { - float alpha2 = alpha * alpha; - float d = 1.0 + (alpha2 - 1.0) * cos_theta_m * cos_theta_m; - return alpha2 / (M_PI * d * d); + float a = cos_theta_m * alpha; + float k = alpha / (1.0 - cos_theta_m * cos_theta_m + a * a); + return k * k * (1.0 / M_PI); } // From Earl Hammon, Jr. "PBR Diffuse Lighting for GGX+Smith Microsurfaces" https://www.gdcvault.com/play/1024478/PBR-Diffuse-Lighting-for-GGX |