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titleSubsurface Scattering Parameters

Subsurface Scattering Parameters

Subsurface Model

Select a subsurface scattering model: Jensen Dipole, DEon d'Eon Better Dipole, Burley Normalized - This is the preferred method, and Multiple Mean Free Paths

Burley Normalized produces the most accurate effect while preserving details.

Jenson Jensen and DEon d'Eon Dipoles are great for very translucent objects like gummies.

Multiple Mean Free Paths is great for texturing to produce color bleed easily. While not necessarily physically correct, its intuitive scattering of textured colors works well for art direction.

 

 

 

Gain

Subsurface scattering weight. Higher numbers increase the visibility of the subsurface scattering.

 

 

Color

Subsurface scattering color.

 

 

Mean Free Path Distance

Subsurface scattering mean free path scalar distance. This specifies how far the light travels inside an object and as a consequence how smooth the subsurface scattering is. This gets multiplied by the unit length set in the Properties section. Higher amounts make the object appear less opaque and more translucent.

 

 

Mean Free Path Color

How far the light travels in the R, G, and B spectra. This is scaled by Mean Free Path Distance. Different colors may spread more or less and provide interesting effects like the red color bleeding into shadow edges on skin.

 

 

Post Tint

Tint that is applied at the end of the subsurface computation. If we want to apply the tint before the subsurface computation, set Irradiance Tint in the Properties section.

 

 

Short Gain

Short subsurface gain or weight. This is only valid for Multiple Mean Free Paths subsurface model.

 

Short Color

Short subsurface color. This is only valid for Multiple Mean Free Paths subsurface model.

 

 

Short MFP Distance

Short subsurface mean free path scalar distance.

 

 

Long Gain

Long subsurface gain or weight. This is only valid for Multiple Mean Free Paths subsurface model.

 

 

Long Color

Long subsurface color. This is only valid for Multiple Mean Free Paths subsurface model.

 

 

Long MFP Distance

Short subsurface mean free path scalar distance.

 

 

Diffuse Computation Switch

Switch the subsurface computation to a diffuse computation if the dmfp is smaller than the ray footprint. This is an optimization to ignore computing scattering, especially on far away objects.

 

 

Double Sided

If on, illuminate on both sides of the surface for this subsurface lobe, that is, this will illuminate the surface whose normal is pointing away from the camera as well.

 

 

Trace Control:

Consider Backside

Whether subsurface respects surfaces on the other side. This is for the hit side, not the illuminating side (which is subsurfaceDoubleSided):

  • "Off" - It will ignore surfaces on the other side completely. This is useful to make objects appear thicker than they are.
  • "On" - Normal mode, where the diffusion happens between the front and the first surface behind it.

 

 

Continuation Ray Mode

Control continuation ray mode:

"Off" - Simply trace out of the object (default).

"Last Hit" - Ignore internal geometry and jump to the last surface.

"All Hits" - Scatter (collect light) on all hits as the ray leaves the object. This can bring additional brightness, at the cost of additional noise.

 

 

Max Continuation Hits

Maximum number of hits to test in all hits mode. This is only valid when Continuation Ray Mode equals All Hits

 

 

Follow Topology

Controls how strongly normals are considered in the subsurface computation. This may affect visible details created through bump mapping as well.

 

 

Trace Subset

Specify trace subset for inclusion/exclusion when struck by a ray indirectly.

 

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