Caustics

Focused specular light reflections and refractions cause caustics. In order to simulated the effects of caustics we need to tell mental ray to
a.) cast photons from our lights and
b.) enable photon mapping in the Render Settings.

Let's start with the light. In a spot light, open the mental ray tab. Look for Caustics and Global Illumination. Here, check the Emit Photons button.

In the Render Settings, choose mental ray as the render engine. Then, set the Quality Preset to Preview Caustics.

In class we'll go over visualization of the photon map and tweaking settings.

The homework assignment is to use the scene below to create caustic renders.

CausticScene