About the icy wall effect
Ice can be a difficult material to replicate because light scatters off it in different ways, depending on the small details of its surface. The reflection can be completely clear, completely distorted, or anywhere in between. The Ice Cave demo shows this effect and includes a parallax effect for greater realism.
The following figure shows the Ice Cave demo, demonstrating this effect:
Figure 5-70 The Ice Cave demo
The following figure shows a close up of this effect:
Figure 5-71 Close up of the reflective icy walls