Location: The Render Manager > Renderer > Optimization
or
The Render Manager > Globals > mental ray > Optimization
You can control whether reflection and refraction are rendered by toggling secondary rays. When secondary rays are active, you may need to adjust the Secondary Rays - Depth settings to accommodate the amount of reflection or refraction in the scene.
Depth refers to the number of times that a ray is reflected or refracted during the raytracing process. Each refraction or reflection of a ray creates a new branch in a ray tree.
You can set the following depth values:
• Reflection sets the maximum number of a ray’s reflective branches in a scene. For example, in a totally reflective scene, the ray continuously bounces around in the scene creating an infinite number of branches. This option lets you set an upper limit on these calculations.
• Refraction sets the maximum number of times a ray can be refracted in a scene. For example, on an object with few smooth sides and a high refractive value, the refraction ray continuously bounces around the scene creating an infinite number of branches. This option lets you set an upper limit on these calculations.
• Combined sets an upper limit on the sum of a ray’s reflections and refractions.
Use higher values for a more accurate image, or use lower values for preview renders or to speed up rendering in scenes with little reflection or refraction.
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