A reflective object can reflect another reflective object. In real life, this creates a virtually infinite number of interreflections.
In solidThinking, you can set the number of interreflections computed when you use the raytrace method.
To set the number of interreflections, open the Shading panel by using either the Managers > Shading command.
Once opened, the Shading panel displays six tabs: Surface, Light, Image, Rendering, Output and Globals.
Select the Globals tab.
In the Parameters column, you can set the number of interreflections either by moving the slider or by typing it in the Reflections data field and pressing Enter. The default value is 4. The higher the number, the slower the computation.