diff options
| -rw-r--r-- | intern/opencolorio/gpu_shader_display_transform.glsl | 23 | ||||
| -rw-r--r-- | source/blender/blenlib/intern/math_color_inline.c | 20 | ||||
| -rw-r--r-- | source/blender/imbuf/intern/divers.c | 4 | ||||
| -rw-r--r-- | source/blender/makesrna/intern/rna_scene.c | 3 |
4 files changed, 35 insertions, 15 deletions
diff --git a/intern/opencolorio/gpu_shader_display_transform.glsl b/intern/opencolorio/gpu_shader_display_transform.glsl index f1f77cf7df2..f7c64244dd6 100644 --- a/intern/opencolorio/gpu_shader_display_transform.glsl +++ b/intern/opencolorio/gpu_shader_display_transform.glsl @@ -115,9 +115,20 @@ vec4 curvemapping_evaluate_premulRGBF(vec4 col) return result; } +/* Using a triangle distribution which gives a more final uniform noise. + * See Banding in Games:A Noisy Rant(revision 5) Mikkel Gjøl, Playdead (slide 27) */ +/* GPUs are rounding before writting to framebuffer so we center the distribution around 0.0. */ +/* Return triangle noise in [-1..1[ range */ float dither_random_value(vec2 co) { - return fract(sin(dot(co.xy, vec2(12.9898, 78.233))) * 43758.5453) * 0.005 * dither; + /* Original code from https://www.shadertoy.com/view/4t2SDh */ + /* Uniform noise in [0..1[ range */ + float nrnd0 = fract(sin(dot(co.xy, vec2(12.9898, 78.233))) * 43758.5453); + /* Convert uniform distribution into triangle-shaped distribution. */ + float orig = nrnd0 * 2.0 - 1.0; + nrnd0 = orig * inversesqrt(abs(orig)); + nrnd0 = max(-1.0, nrnd0); /* Removes nan's */ + return nrnd0 - sign(orig); } vec2 round_to_pixel(sampler2D tex, vec2 uv) @@ -128,7 +139,7 @@ vec2 round_to_pixel(sampler2D tex, vec2 uv) vec4 apply_dither(vec4 col, vec2 uv) { - col.rgb += dither_random_value(uv); + col.rgb += dither_random_value(uv) * 0.0033 * dither; return col; } @@ -151,10 +162,6 @@ vec4 OCIO_ProcessColor(vec4 col, vec4 col_overlay, vec2 noise_uv) col = OCIO_to_display_linear_with_look(col, lut3d_texture); - if (dither > 0.0) { - col = apply_dither(col, noise_uv); - } - if (overlay) { col *= 1.0 - col_overlay.a; col += col_overlay; /* Assumed unassociated alpha. */ @@ -162,6 +169,10 @@ vec4 OCIO_ProcessColor(vec4 col, vec4 col_overlay, vec2 noise_uv) col = OCIO_to_display_encoded(col, lut3d_display_texture); + if (dither > 0.0) { + col = apply_dither(col, noise_uv); + } + return col; } diff --git a/source/blender/blenlib/intern/math_color_inline.c b/source/blender/blenlib/intern/math_color_inline.c index f5aaddc0ea3..52ca229fe27 100644 --- a/source/blender/blenlib/intern/math_color_inline.c +++ b/source/blender/blenlib/intern/math_color_inline.c @@ -317,19 +317,27 @@ MINLINE int compare_rgb_uchar(const unsigned char col_a[3], return 0; } +/* Using a triangle distribution which gives a more final uniform noise. + * See Banding in Games:A Noisy Rant(revision 5) Mikkel Gjøl, Playdead (slide 27) */ +/* Return triangle noise in [-0.5..1.5[ range */ MINLINE float dither_random_value(float s, float t) { - static float vec[2] = {12.9898f, 78.233f}; - float value; - - value = sinf(s * vec[0] + t * vec[1]) * 43758.5453f; - return value - floorf(value); + /* Original code from https://www.shadertoy.com/view/4t2SDh */ + /* The nois reshaping technique does not work on CPU. + * We generate and merge two distribution instead */ + /* Uniform noise in [0..1[ range */ + float nrnd0 = sinf(s * 12.9898f + t * 78.233f) * 43758.5453f; + float nrnd1 = sinf(s * 19.9898f + t * 119.233f) * 43798.5453f; + nrnd0 -= floorf(nrnd0); + nrnd1 -= floorf(nrnd1); + /* Convert uniform distribution into triangle-shaped distribution. */ + return nrnd0 + nrnd1 - 0.5f; } MINLINE void float_to_byte_dither_v3( unsigned char b[3], const float f[3], float dither, float s, float t) { - float dither_value = dither_random_value(s, t) * 0.005f * dither; + float dither_value = dither_random_value(s, t) * 0.0033f * dither; b[0] = unit_float_to_uchar_clamp(dither_value + f[0]); b[1] = unit_float_to_uchar_clamp(dither_value + f[1]); diff --git a/source/blender/imbuf/intern/divers.c b/source/blender/imbuf/intern/divers.c index aa49453d68c..07bbec9e15c 100644 --- a/source/blender/imbuf/intern/divers.c +++ b/source/blender/imbuf/intern/divers.c @@ -75,7 +75,7 @@ MINLINE void ushort_to_byte_dither_v4( uchar b[4], const unsigned short us[4], DitherContext *di, float s, float t) { #define USHORTTOFLOAT(val) ((float)val / 65535.0f) - float dither_value = dither_random_value(s, t) * 0.005f * di->dither; + float dither_value = dither_random_value(s, t) * 0.0033f * di->dither; b[0] = ftochar(dither_value + USHORTTOFLOAT(us[0])); b[1] = ftochar(dither_value + USHORTTOFLOAT(us[1])); @@ -88,7 +88,7 @@ MINLINE void ushort_to_byte_dither_v4( MINLINE void float_to_byte_dither_v4( uchar b[4], const float f[4], DitherContext *di, float s, float t) { - float dither_value = dither_random_value(s, t) * 0.005f * di->dither; + float dither_value = dither_random_value(s, t) * 0.0033f * di->dither; b[0] = ftochar(dither_value + f[0]); b[1] = ftochar(dither_value + f[1]); diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c index cc0903ed2c8..5e5bafdc178 100644 --- a/source/blender/makesrna/intern/rna_scene.c +++ b/source/blender/makesrna/intern/rna_scene.c @@ -5683,7 +5683,8 @@ static void rna_def_scene_render_data(BlenderRNA *brna) prop = RNA_def_property(srna, "dither_intensity", PROP_FLOAT, PROP_NONE); RNA_def_property_float_sdna(prop, NULL, "dither_intensity"); - RNA_def_property_range(prop, 0.0f, 2.0f); + RNA_def_property_range(prop, 0.0, FLT_MAX); + RNA_def_property_ui_range(prop, 0.0, 2.0, 0.1, 2); RNA_def_property_ui_text( prop, "Dither Intensity", |