This tutorial will cover how to create volumetric caustic effects using softimage XSI 2.x and
the xphysics shaders plugin (available from the softimage site).

Workflow Overview

Due to the inability of XSI 2.x to render intersecting volumes we need to split our volumetric
caustics in to two passes.

Our first pass will include just the volumetric caustics - that is all the volumetric light that
interacts with our refractive or reflective surface.

Our second pass will include the volumetric lighting coming directly from our light source.

After we've created both of these passes we will do a simple composite using the FX Tree
to create the final image.

Known Issues

The xphysics shader plugin requires XSI v2.0.3.

The xphysics shader plugin may not function correctly on network rendering. The error will
cause remote machines to not store any photons in your caustics volume.

Start the tutorial

Ok now that you're familiar with the background for this tutorial move on to the first step -
creating the volumetric caustics.