Explain more about the CollisionFidelity property and how it works


Currently the page links to the wikipedia page for “Convex hull” which isn’t the first resource I’d give to developers, but rather some in-engine examples of models affected by it and then later in the page explaining that if developers are interested in more information to go there.

The page notes specifically “The CollisionFidelity property of union objects is not scriptable: it must be set in Studio.” but this should instead just mention the property cannot be set by a script during run time, since geometry cannot be recalculated.

Including some extreme cases where even Default doesn’t work intentionally would also be useful, showing a developer that separating a mesh or making a fake collision (invisible parts) might be ideal right now.

Cases that I think could help a developer understand how it works:


ColissionFidelity is a function which shows what colission it has, usually this is used in unions to make sure Roblox doesn’t shortcut the colission like it usually does.

I think he knows what it does, he just wants the documentation to explain it better for future users.


It’d be cool if we could know the performance costs and benefits in detail too. It’s common knowledge box is best for performance, but I want to know (in one place) how to get the absolute best performance out of my meshes as possible!