I added a model in cannon+three, I don't know why there is no physical characteristics

example:relaxed-margulis-ms8z8v - CodeSandbox

Small balls and squares will penetrate the scene model.
I do not know why it has to be like this.

@boktaryan i think you’ll probably find that a cannon.js simulation runs the same way regardless of which 3D library you use to display its output …

@seanin to your question, in order to catch small objects moving very quickly through thin obstacles, a physics engine needs to implement something called “continuous collision detection” (CCD). I’m not aware of any physics engines that support CCD well, so in effect it’s important to keep objects moving at lower speeds, or have thicker barriers, or run your physics engine at a higher framerate. If an object can move through a barrier in less than the time between updates to the physics simulation, the simulation may “miss” that collision.