diff options
author | Clément Foucault <foucault.clem@gmail.com> | 2018-11-14 17:46:40 +0300 |
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committer | Clément Foucault <foucault.clem@gmail.com> | 2018-11-15 20:16:22 +0300 |
commit | f3074b96d6fe748900d062c7dc3f51f37f06fc5a (patch) | |
tree | 2835bd18db47e3720d3143b0c5a658e8a1043f9f /source | |
parent | cfb6f14616ecd96831815b48c7edfdd706ddcf2e (diff) |
Eevee: Make sun power match cycles better.
I made an empirical test with a 100% diffuse sphere and manually tweak the
lighting power of a sun lamp trying to fit cycles and eevee the best I can.
Then I plotted the result and found a rough fit to the equation and that
seems to work pretty well.
Diffstat (limited to 'source')
3 files changed, 9 insertions, 4 deletions
diff --git a/source/blender/draw/engines/eevee/eevee_lights.c b/source/blender/draw/engines/eevee/eevee_lights.c index 02667bf7087..962cb7c2033 100644 --- a/source/blender/draw/engines/eevee/eevee_lights.c +++ b/source/blender/draw/engines/eevee/eevee_lights.c @@ -663,6 +663,9 @@ static void eevee_light_setup(Object *ob, EEVEE_Light *evli) else { power = 1.0f / (4.0f * evli->radius * evli->radius * M_PI * M_PI) * /* 1/(r²*Pi) */ 12.5f; /* XXX : Empirical, Fit cycles power */ + /* Make illumation power closer to cycles for bigger radii. Cycles uses a cos^3 term that we cannot reproduce + * so we account for that by scaling the light power. This function is the result of a rough manual fitting. */ + power *= 1.0f + evli->radius * evli->radius * 0.5f; } mul_v3_fl(evli->color, power * la->energy); diff --git a/source/blender/draw/engines/eevee/shaders/lamps_lib.glsl b/source/blender/draw/engines/eevee/shaders/lamps_lib.glsl index a2a26c0fbf0..ecc1a817dae 100644 --- a/source/blender/draw/engines/eevee/shaders/lamps_lib.glsl +++ b/source/blender/draw/engines/eevee/shaders/lamps_lib.glsl @@ -411,7 +411,8 @@ vec3 light_translucent(LightData ld, vec3 W, vec3 N, vec4 l_vector, float scale) falloff = dot(N, l_vector.xyz / l_vector.w); } else if (ld.l_type == SUN) { - vis *= (4.0f * ld.l_radius * ld.l_radius * M_2PI) * (1.0 / 12.5); /* Removing area light power*/ + vis /= 1.0f + (ld.l_radius * ld.l_radius * 0.5f); + vis *= ld.l_radius * ld.l_radius * M_PI; /* Removing area light power*/ vis *= M_2PI * 0.78; /* Matching cycles with point light. */ vis *= 0.082; /* XXX ad hoc, empirical */ falloff = dot(N, -ld.l_forward); diff --git a/source/blender/draw/engines/eevee/shaders/volumetric_lib.glsl b/source/blender/draw/engines/eevee/shaders/volumetric_lib.glsl index 36c4562e137..ae36252153f 100644 --- a/source/blender/draw/engines/eevee/shaders/volumetric_lib.glsl +++ b/source/blender/draw/engines/eevee/shaders/volumetric_lib.glsl @@ -74,7 +74,8 @@ vec3 light_volume(LightData ld, vec4 l_vector) power *= 20.0 * max(0.0, dot(-ld.l_forward, l_vector.xyz / l_vector.w)); /* XXX ad hoc, empirical */ } else if (ld.l_type == SUN) { - power = (4.0f * ld.l_radius * ld.l_radius * M_2PI) * (1.0 / 12.5); /* Removing area light power*/ + power = ld.l_radius * ld.l_radius * M_PI; /* Removing area light power*/ + power /= 1.0f + (ld.l_radius * ld.l_radius * 0.5f); power *= M_PI * 0.5; /* Matching cycles. */ } else { @@ -82,12 +83,12 @@ vec3 light_volume(LightData ld, vec4 l_vector) power *= M_2PI; /* Matching cycles with point light. */ } + power /= (l_vector.w * l_vector.w); + /* OPTI: find a better way than calculating this on the fly */ float lum = dot(ld.l_color, vec3(0.3, 0.6, 0.1)); /* luminance approx. */ vec3 tint = (lum > 0.0) ? ld.l_color / lum : vec3(1.0); /* normalize lum. to isolate hue+sat */ - power /= (l_vector.w * l_vector.w); - lum = min(lum * power, volLightClamp); return tint * lum; |