Houdini 20.5 Shelf tools

Expand from Objects shelf tool

Creates a force that pushes fluid away from the selected object.

On this page

Overview

This shelf tool uses a FLIP Source node to convert the selected geometry into a divergence volume that can be used to exert an expansive force on a fluid system. This is useful for manually creating and controlling explosions.

Using Expand from Objects

To...Do this

Create a fluid container

See Smoke Container or Pyro Container.

Fill a fluid container

See Source from Surface, Source from Points, and Source from Volume.

Create an expansion force

  1. Select the object you want to turn into an expansion field.

  2. On the Populate Containers tab, click the Expand from Objects tool.

  3. Select the fluid container you want to expand in and press Enter.

Control the amount of expansion

In the DOP network, find the Volume Source node importing the divergence field (named source_divergence_from_‹object›).

Use the Scale parameter on the divergence import to control the amount of expansion. You can keyframe this value to delay and/or limit the expansion time, pulse the expansion, etc.

Sometimes very high values may be necessary (100+) to have visible effects.
See also

Shelf tools

Using the shelf

  • Customize the shelf

    How to change the look of the shelf, change and rearrange its contents, and create your own shelf tools.

Technical