The tool fills an object with spheres and uses the Bullet solver to drive them. For small numbers of sand grains, (less than a thousand) Bullet is both faster and produces better results. In particular, with Bullet you can get the grains rolling off piles as you have orientations. This is useful for close up shots where you can see individual grains or for scenes where the particles are big such as corn kernels or a ball pit.

1. Select the geometry object to convert to RBD grains.

2. Click the RBD Grains tool on the Grains tab.