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| //* 1.0.0 - first version | |
| //* 1.0.1 - fix reflection and transmission with subsurface color | |
| //* 1.0.2 - Fix EDF in the back side: the EDF contained in surface is only used for the front side and not for the back side | |
| //* 1.0.3 - using absolute import paths when importing standard modules | |
| mdl 1.3; | |
| import ::df::*; | |
| import ::state::*; | |
| import ::math::*; | |
| import ::tex::*; | |
| import ::anno::*; | |
| export annotation distill_off(); | |
| float emissive_multiplier() | |
| [[ | |
| anno::description("the multiplier to convert UE4 emissive to raw data"), | |
| anno::noinline() | |
| ]] | |
| { | |
| return 20.0f * 128.0f; | |
| } | |
| float get_subsurface_weight() | |
| [[ | |
| anno::noinline() | |
| ]] | |
| { | |
| return 0.5f; | |
| } | |
| color get_subsurface_color(color subsurface_color) | |
| [[ | |
| anno::noinline() | |
| ]] | |
| { | |
| return subsurface_color; | |
| } | |
| float get_subsurface_opacity(float subsurface_opacity) | |
| [[ | |
| anno::noinline() | |
| ]] | |
| { | |
| return subsurface_opacity; | |
| } | |
| float3 tangent_space_normal( | |
| float3 normal = float3(0.0,0.0,1.0), | |
| float3 tangent_u = state::texture_tangent_u(0), | |
| float3 tangent_v = state::texture_tangent_v(0) | |
| ) | |
| [[ | |
| anno::description("Interprets the vector in tangent space"), | |
| anno::noinline() | |
| ]] | |
| { | |
| return math::normalize( | |
| tangent_u * normal.x - /* flip_tangent_v */ | |
| tangent_v * normal.y + | |
| state::normal() * (normal.z)); | |
| } | |
| float3 world_space_normal( | |
| float3 normal = float3(0.0,0.0,1.0), | |
| float3 tangent_u = state::texture_tangent_u(0), | |
| float3 tangent_v = state::texture_tangent_v(0) | |
| ) | |
| [[ | |
| anno::description("Interprets the vector in world space"), | |
| anno::noinline() | |
| ]] | |
| { | |
| return tangent_space_normal( | |
| math::normalize( | |
| normal.x * float3(tangent_u.x, tangent_v.x, state::normal().x) - | |
| normal.y * float3(tangent_u.y, tangent_v.y, state::normal().y) + | |
| normal.z * float3(tangent_u.z, tangent_v.z, state::normal().z)), | |
| tangent_u, | |
| tangent_v | |
| ); | |
| } | |
| export material OmniUe4Subsurface( | |
| float3 base_color = float3(0.0, 0.0, 0.0), | |
| float metallic = 0.0, | |
| float roughness = 0.5, | |
| float specular = 0.5, | |
| float3 normal = float3(0.0,0.0,1.0), | |
| uniform bool enable_opacity = true, | |
| float opacity = 1.0, | |
| float opacity_mask = 1.0, | |
| float3 emissive_color = float3(0.0, 0.0, 0.0), | |
| float3 subsurface_color = float3(1.0, 1.0, 1.0), | |
| float3 displacement = float3(0.0), | |
| uniform bool is_tangent_space_normal = true, | |
| uniform bool two_sided = false | |
| ) | |
| [[ | |
| anno::display_name("Omni UE4 Subsurface"), | |
| anno::description("Omni UE4 Subsurface, supports UE4 Subsurface shading model"), | |
| anno::version( 1, 0, 0), | |
| anno::author("NVIDIA CORPORATION"), | |
| anno::key_words(string[]("omni", "UE4", "omniverse", "subsurface")), | |
| distill_off() | |
| ]] | |
| = let { | |
| color final_base_color = math::saturate(base_color); | |
| float final_metallic = math::saturate(metallic); | |
| float final_roughness = math::saturate(roughness); | |
| float final_specular = math::saturate(specular); | |
| color final_emissive_color = math::max(emissive_color, 0.0f) * emissive_multiplier(); /*factor for converting ue4 emissive to raw value*/ | |
| float3 final_normal = math::normalize(normal); | |
| color final_subsurface_color = math::saturate(subsurface_color); | |
| float final_opacity = math::saturate(opacity); | |
| // - compute final roughness by squaring the "roughness" parameter | |
| float alpha = final_roughness * final_roughness; | |
| // reduce the reflectivity at grazing angles to avoid "dark edges" for high roughness due to the layering | |
| float grazing_refl = math::max((1.0 - final_roughness), 0.0); | |
| bsdf reflection_component = df::diffuse_reflection_bsdf(tint: final_base_color); | |
| bsdf subsurface_reflection_component = df::diffuse_reflection_bsdf(tint: get_subsurface_color(subsurface_color: final_subsurface_color)); | |
| bsdf transmit_component = df::diffuse_transmission_bsdf(tint: get_subsurface_color(subsurface_color: final_subsurface_color)); | |
| // for the dielectric component we layer the glossy component on top of the diffuse one, | |
| // the glossy layer has no color tint | |
| bsdf dielectric_component = df::custom_curve_layer( | |
| weight: final_specular, | |
| normal_reflectivity: 0.08, | |
| grazing_reflectivity: grazing_refl, | |
| layer: df::microfacet_ggx_smith_bsdf(roughness_u: alpha), | |
| base: df::normalized_mix( | |
| components: | |
| df::bsdf_component[]( | |
| df::bsdf_component( | |
| component: reflection_component, | |
| weight: 1.0f - get_subsurface_weight()), | |
| df::bsdf_component( | |
| component: subsurface_reflection_component, | |
| weight: get_subsurface_opacity(subsurface_opacity: final_opacity) * get_subsurface_weight()), | |
| df::bsdf_component( | |
| component: transmit_component, | |
| weight: (1.0 - get_subsurface_opacity(subsurface_opacity: final_opacity)) * get_subsurface_weight()) | |
| ) | |
| ) | |
| ); | |
| // the metallic component doesn't have a diffuse component, it's only glossy | |
| // base_color is applied to tint it | |
| bsdf metallic_component = df::microfacet_ggx_smith_bsdf(tint: final_base_color, roughness_u: alpha); | |
| // final BSDF is a linear blend between dielectric and metallic component | |
| bsdf dielectric_metal_mix = | |
| df::normalized_mix( | |
| components: | |
| df::bsdf_component[]( | |
| df::bsdf_component( | |
| component: metallic_component, | |
| weight: final_metallic), | |
| df::bsdf_component( | |
| component: dielectric_component, | |
| weight: 1.0-final_metallic) | |
| ) | |
| ); | |
| float3 the_normal = is_tangent_space_normal ? | |
| tangent_space_normal( | |
| normal: final_normal, | |
| tangent_u: state::texture_tangent_u(0), | |
| tangent_v: state::texture_tangent_v(0) | |
| ) : world_space_normal( | |
| normal: final_normal, | |
| tangent_u: state::texture_tangent_u(0), | |
| tangent_v: state::texture_tangent_v(0) | |
| ); | |
| bsdf surface = dielectric_metal_mix; | |
| } | |
| in material( | |
| thin_walled: two_sided, // Graphene? | |
| surface: material_surface( | |
| scattering: surface, | |
| emission: | |
| material_emission ( | |
| emission: df::diffuse_edf (), | |
| intensity: final_emissive_color | |
| ) | |
| ), | |
| backface: material_surface( | |
| emission: | |
| material_emission ( | |
| emission: df::diffuse_edf (), | |
| intensity: final_emissive_color | |
| ) | |
| ), | |
| geometry: material_geometry( | |
| displacement: displacement, | |
| normal: the_normal, | |
| cutout_opacity: enable_opacity ? opacity_mask : 1.0 | |
| ) | |
| ); | |