Eevee: SSS: Add separated Albedo option.

This option prevent from automatically blurring the albedo color applied to the SSS.

While this is great for preserving details it can bleed more light onto the nearby objects since the blurring will be done on pure "white" irradiance.
This issue is to be tackled in a separate commit.

1 files changed, 14 insertions, 2 deletions

diff --git a/source/blender/gpu/shaders/gpu_shader_material.glsl b/source/blender/gpu/shaders/gpu_shader_material.glsl
index b23c1708ee1..9d22fbba65e 100644
--- a/source/blender/gpu/shaders/gpu_shader_material.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_material.glsl
@@ -2909,7 +2909,12 @@ void node_bsdf_principled_clearcoat(vec4 base_color, float subsurface, vec3 subs
 	result.ssr_id = int(ssr_id);
 #ifdef USE_SSS
 	result.sss_data.a = sss_scalef;
-	result.sss_data.rgb = (out_diff + out_trans) * mix(vec3(0.0), subsurface_color.rgb, subsurface);
+	result.sss_data.rgb = out_diff + out_trans;
+#ifdef USE_SSS_ALBEDO
+	result.sss_albedo.rgb = mix(vec3(0.0), subsurface_color.rgb, subsurface);
+#else
+	result.sss_data.rgb *= mix(vec3(0.0), subsurface_color.rgb, subsurface);
+#endif
 	result.sss_data.rgb *= (1.0 - transmission);
 #endif
 
@@ -2954,7 +2959,14 @@ void node_subsurface_scattering(
 	result.ssr_id = -1;
 	result.sss_data.a = scale;
 	eevee_closure_subsurface(N, color.rgb, 1.0, scale, out_diff, out_trans);
-	result.sss_data.rgb = (out_diff + out_trans) * color.rgb;
+	result.sss_data.rgb = out_diff + out_trans;
+#ifdef USE_SSS_ALBEDO
+	/* Not perfect for texture_blur not exaclty equal to 0.0 or 1.0. */
+	result.sss_albedo.rgb = mix(color.rgb, vec3(1.0), texture_blur);
+	result.sss_data.rgb *= mix(vec3(1.0), color.rgb, texture_blur);
+#else
+	result.sss_data.rgb *= color.rgb;
+#endif
 #else
 	node_bsdf_diffuse(color, 0.0, N, result);
 #endif