Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Replace current ACES tonemapper with a high quality one #52476

Merged
merged 1 commit into from
Sep 9, 2021
Merged

Replace current ACES tonemapper with a high quality one #52476

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
48 changes: 32 additions & 16 deletions servers/rendering/renderer_rd/shaders/tonemap.glsl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -169,16 +169,33 @@ vec3 tonemap_filmic(vec3 color, float white) {
return color_tonemapped / white_tonemapped;
}

// Adapted from https://github.com/TheRealMJP/BakingLab/blob/master/BakingLab/ACES.hlsl
// (MIT License).
vec3 tonemap_aces(vec3 color, float white) {
const float exposure_bias = 0.85f;
const float A = 2.51f * exposure_bias * exposure_bias;
const float B = 0.03f * exposure_bias;
const float C = 2.43f * exposure_bias * exposure_bias;
const float D = 0.59f * exposure_bias;
const float E = 0.14f;

vec3 color_tonemapped = (color * (A * color + B)) / (color * (C * color + D) + E);
float white_tonemapped = (white * (A * white + B)) / (white * (C * white + D) + E);
const float exposure_bias = 1.8f;
const float A = 0.0245786f;
const float B = 0.000090537f;
const float C = 0.983729f;
const float D = 0.432951f;
const float E = 0.238081f;

// Exposure bias baked into transform to save shader instructions. Equivalent to `color *= exposure_bias`
const mat3 rgb_to_rrt = mat3(
vec3(0.59719f * exposure_bias, 0.35458f * exposure_bias, 0.04823f * exposure_bias),
vec3(0.07600f * exposure_bias, 0.90834f * exposure_bias, 0.01566f * exposure_bias),
vec3(0.02840f * exposure_bias, 0.13383f * exposure_bias, 0.83777f * exposure_bias));

const mat3 odt_to_rgb = mat3(
vec3(1.60475f, -0.53108f, -0.07367f),
vec3(-0.10208f, 1.10813f, -0.00605f),
vec3(-0.00327f, -0.07276f, 1.07602f));

color *= rgb_to_rrt;
vec3 color_tonemapped = (color * (color + A) - B) / (color * (C * color + D) + E);
color_tonemapped *= odt_to_rgb;

white *= exposure_bias;
float white_tonemapped = (white * (white + A) - B) / (white * (C * white + D) + E);

return color_tonemapped / white_tonemapped;
}
Expand All @@ -200,15 +217,16 @@ vec3 linear_to_srgb(vec3 color) {
#define TONEMAPPER_ACES 3

vec3 apply_tonemapping(vec3 color, float white) { // inputs are LINEAR, always outputs clamped [0;1] color

// Ensure color values passed to tonemappers are positive.
// They can be negative in the case of negative lights, which leads to undesired behavior.
if (params.tonemapper == TONEMAPPER_LINEAR) {
return color;
} else if (params.tonemapper == TONEMAPPER_REINHARD) {
return tonemap_reinhard(color, white);
return tonemap_reinhard(max(vec3(0.0f), color), white);
} else if (params.tonemapper == TONEMAPPER_FILMIC) {
return tonemap_filmic(color, white);
return tonemap_filmic(max(vec3(0.0f), color), white);
} else { // TONEMAPPER_ACES
return tonemap_aces(color, white);
return tonemap_aces(max(vec3(0.0f), color), white);
}
}

Expand Down Expand Up @@ -401,9 +419,7 @@ void main() {
color += screen_space_dither(gl_FragCoord.xy);
}

// Ensure color values passed to tonemappers are positive.
// They can be negative in the case of negative lights, which leads to undesired behavior.
color = apply_tonemapping(max(vec3(0.0), color), params.white);
color = apply_tonemapping(color, params.white);

color = linear_to_srgb(color); // regular linear -> SRGB conversion

Expand Down