Clément Foucault
83ac8628c4
This modifies the principled BSDF and the Glass BSDF which now have better fit to multiscatter GGX. Code to generate the LUT have been updated and can run at runtime. The refraction LUT has been changed to have the critical angle always centered around one pixel so that interpolation can be mitigated. Offline LUT data will be updated in another commit This simplify the BTDF retreival removing the manual clean cut at low roughness. This maximize the precision of the LUT by scalling the sides by the critical angle. I also touched the ior > 1.0 approximation to be smoother. Also incluse some cleanup of bsdf_sampling.glsl
58 lines
2.2 KiB
GLSL
58 lines
2.2 KiB
GLSL
#ifndef VOLUMETRICS
|
|
|
|
CLOSURE_EVAL_FUNCTION_DECLARE_2(node_bsdf_glass, Glossy, Refraction)
|
|
|
|
void node_bsdf_glass(vec4 color,
|
|
float roughness,
|
|
float ior,
|
|
vec3 N,
|
|
const float do_multiscatter,
|
|
const float ssr_id,
|
|
out Closure result)
|
|
{
|
|
CLOSURE_VARS_DECLARE_2(Glossy, Refraction);
|
|
|
|
in_Glossy_0.N = N; /* Normalized during eval. */
|
|
in_Glossy_0.roughness = roughness;
|
|
|
|
in_Refraction_1.N = N; /* Normalized during eval. */
|
|
in_Refraction_1.roughness = roughness;
|
|
in_Refraction_1.ior = ior;
|
|
|
|
CLOSURE_EVAL_FUNCTION_2(node_bsdf_glass, Glossy, Refraction);
|
|
|
|
result = CLOSURE_DEFAULT;
|
|
|
|
float NV = dot(in_Refraction_1.N, cameraVec);
|
|
|
|
float fresnel = (do_multiscatter != 0.0) ?
|
|
btdf_lut(NV, in_Refraction_1.roughness, in_Refraction_1.ior).y :
|
|
F_eta(in_Refraction_1.ior, NV);
|
|
|
|
vec2 split_sum = brdf_lut(NV, in_Glossy_0.roughness);
|
|
vec3 brdf = (do_multiscatter != 0.0) ? F_brdf_multi_scatter(vec3(1.0), vec3(1.0), split_sum) :
|
|
F_brdf_single_scatter(vec3(1.0), vec3(1.0), split_sum);
|
|
|
|
out_Glossy_0.radiance = closure_mask_ssr_radiance(out_Glossy_0.radiance, ssr_id);
|
|
out_Glossy_0.radiance *= brdf;
|
|
out_Glossy_0.radiance = render_pass_glossy_mask(vec3(1.0), out_Glossy_0.radiance);
|
|
out_Glossy_0.radiance *= color.rgb * fresnel;
|
|
closure_load_ssr_data(
|
|
out_Glossy_0.radiance, in_Glossy_0.roughness, in_Glossy_0.N, ssr_id, result);
|
|
|
|
float btdf = (do_multiscatter != 0.0) ?
|
|
1.0 :
|
|
btdf_lut(NV, in_Refraction_1.roughness, in_Refraction_1.ior).x;
|
|
out_Refraction_1.radiance *= btdf;
|
|
out_Refraction_1.radiance = render_pass_glossy_mask(vec3(1.0), out_Refraction_1.radiance);
|
|
out_Refraction_1.radiance *= color.rgb * (1.0 - fresnel);
|
|
/* Simulate 2nd absorption event. */
|
|
out_Refraction_1.radiance *= (refractionDepth > 0.0) ? color.rgb : vec3(1.0);
|
|
result.radiance += out_Refraction_1.radiance;
|
|
}
|
|
|
|
#else
|
|
/* Stub glass because it is not compatible with volumetrics. */
|
|
# define node_bsdf_glass(a, b, c, d, e, f, result) (result = CLOSURE_DEFAULT)
|
|
#endif
|