Crystal Renders, Fracturing by Material Type with RBD Tools in Houdini

Download Houdini File (completed project): RBD_Tools_Tutorial_Crystal.hiplc

Download Houdini File (only starter geometry): RBD_Tools_Tutorial_Crystal_only_starter_geo.hiplc

Shattered Crystal rendered in Houdini Redshift

This HIP file is the completed project in a 3 part video series that demonstrates how to fracture a geometry and add interior noise displacement using RBD Tools.

The last video covers how to blend two different types of materials together in Redshift to complete the project from end to end.

End Result of Each Video in the 3 Part Series

Interior Noise Ramp

The Noise Bias Ramp amplifies the noise amplitude according to the depth level of each fractured piece of the geometry. For every piece fractured by the RBD Material Fracture node, we get an “inside” group. The insides of each piece has a certain depth level towards the central point of each piece.

This ramp is very similar to the Height ramp in Height Fields, which I have a very detailed explanation here.

The ramp from left to right remaps to the depth level of each piece, the left side being closest to the surface edge and right being the deepest section.

As pegs are placed all over the ramp, it indicates the level of noise bias that we want to displace on the fractured piece. If the peg is placed higher, more noise will appear at the corresponding depth level. I like to think of the bias like the noise amplitude. And the higher the peg is placed, the more noise is applied and the lower the peg the less likely noise will appear.

If you select “Visualize Noise Scale” the RBD Interior Detail node can also colorize the pieces by noise levels.

Red indicates high noise areas and purple indicates low noise areas.