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Removed clamping of the Linear tonemapping when KEEP_3D_LINEAR

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Changed the behaviour of the Linear tonemapping operator to not clamp to [0, 1] range
in the case when KEEP_3D_LINEAR is defined. This allows to render values > 1.0 in
floating point texture targets (via Viewport) for further processing or saving high
dynamic range data into files. This only works when no color conversion is active.
This commit is contained in:
Holger Dammertz 2019-08-28 21:04:28 +02:00
parent 208dd5b4a6
commit aa3ef8893b
2 changed files with 13 additions and 5 deletions
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2
doc/classes/Environment.xml
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@ -306,7 +306,7 @@
Replace glow blending mode. Replaces all pixels' color by the glow value.
</constant>
<constant name="TONE_MAPPER_LINEAR" value="0" enum="ToneMapper">
Linear tonemapper operator. Reads the linear data and performs an exposure adjustment.
Linear tonemapper operator. Reads the linear data and passes it on unmodified.
</constant>
<constant name="TONE_MAPPER_REINHARDT" value="1" enum="ToneMapper">
Reinhardt tonemapper operator. Performs a variation on rendered pixels' colors by this formula: [code]color = color / (1 + color)[/code].

16
drivers/gles3/shaders/tonemap.glsl
View file

@ -164,7 +164,8 @@ vec3 linear_to_srgb(vec3 color) { // convert linear rgb to srgb, assumes clamped
return mix((vec3(1.0f) + a) * pow(color.rgb, vec3(1.0f / 2.4f)) - a, 12.92f * color.rgb, lessThan(color.rgb, vec3(0.0031308f)));
}
vec3 apply_tonemapping(vec3 color, float white) { // inputs are LINEAR, always outputs clamped [0;1] color
// inputs are LINEAR, If Linear tonemapping is selected no transform is performed else outputs are clamped [0, 1] color
vec3 apply_tonemapping(vec3 color, float white) {
#ifdef USE_REINHARD_TONEMAPPER
return tonemap_reinhard(color, white);
#endif
@ -177,7 +178,7 @@ vec3 apply_tonemapping(vec3 color, float white) { // inputs are LINEAR, always o
return tonemap_aces(color, white);
#endif
return clamp(color, vec3(0.0f), vec3(1.0f)); // no other selected -> linear
return color; // no other selected -> linear: no color transform applied
}
vec3 gather_glow(sampler2D tex, vec2 uv) { // sample all selected glow levels
@ -220,10 +221,14 @@ vec3 apply_glow(vec3 color, vec3 glow) { // apply glow using the selected blendi
#endif
#ifdef USE_GLOW_SCREEN
//need color clamping
color = clamp(color, vec3(0.0f), vec3(1.0f));
color = max((color + glow) - (color * glow), vec3(0.0));
#endif
#ifdef USE_GLOW_SOFTLIGHT
//need color clamping
color = clamp(color, vec3(0.0f), vec3(1.0));
glow = glow * vec3(0.5f) + vec3(0.5f);
color.r = (glow.r <= 0.5f) ? (color.r - (1.0f - 2.0f * glow.r) * color.r * (1.0f - color.r)) : (((glow.r > 0.5f) && (color.r <= 0.25f)) ? (color.r + (2.0f * glow.r - 1.0f) * (4.0f * color.r * (4.0f * color.r + 1.0f) * (color.r - 1.0f) + 7.0f * color.r)) : (color.r + (2.0f * glow.r - 1.0f) * (sqrt(color.r) - color.r)));
@ -265,14 +270,16 @@ void main() {
color *= exposure;
// Early Tonemap & SRGB Conversion
// Early Tonemap & SRGB Conversion; note that Linear tonemapping does not clamp to [0, 1]; some operations below expect a [0, 1] range and will clamp
color = apply_tonemapping(color, white);
#ifdef KEEP_3D_LINEAR
// leave color as is (-> don't convert to SRGB)
#else
color = linear_to_srgb(color); // regular linear -> SRGB conversion
//need color clamping
color = clamp(color, vec3(0.0f), vec3(1.0f));
color = linear_to_srgb(color); // regular linear -> SRGB conversion (needs clamped values)
#endif
// Glow
@ -282,6 +289,7 @@ void main() {
// high dynamic range -> SRGB
glow = apply_tonemapping(glow, white);
glow = clamp(glow, vec3(0.0f), vec3(1.0f));
glow = linear_to_srgb(glow);
color = apply_glow(color, glow);