#Renderman skin shader skin

#Renderman skin shader skin

The heart of realistic skin shading lies in Subsurface Scattering, which is the penetration and resulting scattering of light into a surface. Setting the Displacement Bound too high is inefficient and can make your render slow, so try to set this value as tight as possible. For our head, 0.1 will extend the surface bounding box 10%, which is enough to account for any slight displaced skin features such as moles. Some attributes to keep in mind are ' Adjust Amount' in the PxrBump node, which tells RenderMan to keep the edges from flipping the normals and creating artifacts, as well as ' Displacement Bound' which is a crucial attribute in RenderMan for specifying a bounding box for the displacement. The bump and displacement amounts need to be dialed in manually. Sorry Lee, you're not that wrinkly, I exaggerated the bumpiness a bit in order to illustrate surface properties more clearly and their interaction with the different subsurface models.Īs we can see in the Layered shading network below (I recommend looking at the high-resolution image in the gallery), we are sharing the same texture file for our bump and displacement. It is important to use the highest bit depth possible for data maps to avoid compression or banding artifacts. This will displace the surface inward with values below 0.5, and outward with any value above. To encode the values correctly, we are using a remap value of 'Centered' which will tell RenderMan that the undisplaced value is 0.5, instead of black. We're also modifying the Remapping Mode, given that our texture map is black and white and has no negative values to tell the surface when to displace inward.

In our case, our texture map is a traditional grayscale displacement map, so we're using Scalar as our data type in the PxrDispTransform node. We're doing this by using PxrDisplace which deals with the amount of displacement, and a PxrDispTransform, which deals with the encoding of the displacement file. We are combining Displacements and Bump mapping to achieve the most detail possible from the 16-bit integer displacement map.