I have a very basic grid, with a mountain SOP, that I have turned into a Terrain Object (following the SideFX Tutorial “Dynamics” in Learning Lesson 11).

I then create a sphere, turn it into an RBD Object, and transform it above the grid.

Without touching any other settings, I play the simulation as Ari Danesh does in the tutorial, and his sphere falls and goes into the contours of the mountain grid. However, mine does not. It stops at what the highest point of the grid would be, and rolls horizontally, as if it were an invisible box. This is all on the default bullet solver.

When I change to an RBD solver, it interacts properly.

Is this just something buggy with my Houdini install, or has the Bullet solver/default settings been changed since that tutorial?

in RBD Object node: Collision -> Bullet Data uncheck “Polygon As Convex Hulls”

I hope that this is help

Strange, that never worked before when someone suggested it but it seems to have worked now. Thanks cyber!

Is this just something to always leave unchecked then, if you are using Bullet solver for terrain objects, or is it just recommended to use RBD solver for complex objects always?

Eucalyptus
Is this just something to always leave unchecked

It all about performance, so You can import Non-covex objects and then import convex objects.