Common Issues

There's a large pyramid when I break something

The object has to be closed, manifold (edges have no more than 2 adjacent polygons), with outward-facing normals, and no self-intersections.

The scene is slow when I rewind or locks up when I connect a large object

Increase the 'point separation' before connecting it. This is a world-space sampling distance used to convert all objects to a point-based representation. (Enable 'Draw points' to see the point cloud.)

The sim looks wrong after baking to keys, objects are far apart

Make sure the scene units are centimeters. Other units are currently not supported.

The simulation sometimes explodes using the internal solver

Set a velocity limit. Use the numeric display (before or after baking to keys) to find a sensible maximum value.

The simulation sometimes explodes immediately with Bullet

Change the shape class to btGImpactMeshShape. Sometimes bullet has problems dealing with collision between convex and non-convex objects.

I cannot animate things without the solver running

Uncheck active on the simulator globals tab.

Deformable collision objects don't work with Bullet

These are only supported by the internal solver.