Eevee: Initial Separable Subsurface Scattering implementation.

How to use:
- Enable subsurface scattering in the render options.
- Add Subsurface BSDF to your shader.
- Check "Screen Space Subsurface Scattering" in the material panel options.

This initial implementation has a few limitations:
- only supports gaussian SSS.
- Does not support principled shader.
- The radius parameters is baked down to a number of samples and then put into an UBO. This means the radius input socket cannot be used. You need to tweak the default vector directly.
- The "texture blur" is considered as always set to 1

1 files changed, 5 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_material.c b/source/blender/makesrna/intern/rna_material.c
index 7f23cd78779..a78ad4262ce 100644
--- a/source/blender/makesrna/intern/rna_material.c
+++ b/source/blender/makesrna/intern/rna_material.c
@@ -1877,6 +1877,11 @@ void RNA_def_material(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Screen Space Refraction", "Use raytraced screen space refractions");
 	RNA_def_property_update(prop, 0, "rna_Material_draw_update");
 
+	prop = RNA_def_property(srna, "use_screen_subsurface", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "blend_flag", MA_BL_SS_SUBSURFACE);
+	RNA_def_property_ui_text(prop, "Screen Space Subsurface Scattering", "Use post process subsurface scattering");
+	RNA_def_property_update(prop, 0, "rna_Material_draw_update");
+
 	prop = RNA_def_property(srna, "refraction_depth", PROP_FLOAT, PROP_DISTANCE);
 	RNA_def_property_float_sdna(prop, NULL, "refract_depth");
 	RNA_def_property_range(prop, 0.0f, FLT_MAX);