home about gallery publications education links contact

..::faked sub surface scattering::..

Enlarge Screenshot To create this type of effect without resulting to scripts (though there are some nice ones out there to produce such an effect based on vertex lighting; there is also a nice one out there that uses a similar technique as in this article on Scriptspot.com) you have one main visible option and that is to use the Translucent shader in a Standard Material or in a Raytrace material. Unfortunately though the end results look pretty rubbish as shown here. However you do have an alternative solution, although it does work best with individual objects and not multiple-part objects such as large connected geometry.
Enlarge Screenshot To create it, add a Gradient Ramp map to the Self-Illumination slot of your material and, with Self-Illumination Color checked, design the falloff gradient as illustrated so that the shadow side is at the left of the gradient. The thing to concentrate on here is the mid-range shading so that the colour around the lit/shaded border on the object is diffused nicely. Set the Source Type to Mapped and add any subtle Noise you may want (though bear in mind this uses existing Map channels).
Enlarge Screenshot The main crux of this method is in the Gradient Ramp map’s Source Map slot – namely a Falloff map set to Distance Blend and Falloff Direction to Object. The main scene’s light can be introduced to its Mode Specific Parameters group however a little bit of working out the surface distances based on object width will be required. The distance values can be extrapolated by referencing the Target value of the scene’s Direct light.
Download the max file! Zip file to accompany.

Initially published: 3D World magazine, Issue 109, November 2008.

Copyright Pete Draper, November 2008. Reproduction without permission prohibited.