3.3 Modeling volumes

This chapter provides recommendations about modeling neighbouring volumes and enclosed volumes. When modeling neighbouring volumes such as liquids in basins or different layers of liquids, you can handle this situation in two different ways:
This image shows non-overlapping volumes. The layer of air that separates them causes non-realistic refraction effects.
This image shows overlapping volumes, which shows the physically correct variant.
Note: When rendering with Iray, a slight overlap is the recommended modeling technique for neighbouring volumes.
When modeling enclosed volumes, no special modeling guidelines need to be considered to ensure correct rendering results. The following line drawing provides a simple example - a glass of water with ice cubes that contain air bubbles.
Ice cubes in the water scene setup
Ice cubes in the water render correctly with non-overlapping volumes. When modeling the air bubbles, the ice cubes and the water, it is not necessary that these overlap as the air bubbles are enclosed by the ice cubes, which are again enclosed by the water. The glass and the water are neighbouring volumes however, so they should be modeled with a slight overlap.