Houdini 16.5 Shelf tools Grains tab

Dry Sand shelf tool

Creates a grain object from a piece of geometry.

On this page

This tool lets you pick a piece of geometry and fill it with closely packed grains that move independently. It is useful for creating sand that’s at rest such as a sandbox or a beach, as well as pouring sand such as an hour glass.

Using Dry Sand

  1. Select the geometry object to convert to dry sand.

  2. Click the Dry Sand tool on the Grains tab.

For specific parameter information, see the POP Grains help.

Note

Scaling is an issue for sand because the number of grains are based on how many particles are around it. Changing resolutions may change results.

Tips

  • When making piles of sand, you can edit the Constraint Iterations parameter on the POP Grains node. This will control how many particles high you want the pile to be.

    Note

    This is set relatively low by default for speed purposes.

    You may also want to increase the Scale Kinetic Friction parameter to make nicer looking piles. Increasing this value will make the sand stick together more.

  • Increasing the Shock Scaling Power on the POP Grains node will tame the initial bounce to create fluffier piles that almost look like snow.

    Note

    Another way to tame the initial bounce is to turn off Shock Scaling Power, and turn it on again once the particles hit the ground. This force is needed in order to create piles.

  • Turning on Use OpenCL will make the simulations much faster, but with limitations. See the POP Grains help for more information.

Grains tab