When creating the 3D environment for my game, I have ran across this particular issue a number of times. For whatever reason, holes that are cut into unions are not passable. Visually, the hole is there, but when someone tries to walk through, they stop like there is a physical barrier there but there isn’t. As shown in the screenshot below, when I look at my character in explorer and examine the humanoid, the
Humanoid.FloorMaterial property shows as
Metal which is what the material of the part is, even though I am standing on the opening. What I expect to happen is that I pass through the opening without being blocked.
Although I have tried all four settings for
CollisionFidelity, it seems that
PreciseConvexDecomposition is the one that minimizes the size of the blocked area. However, the issue is still there as part of the opening is still blocked.
It is interesting to note that this seems to occur randomly on unions that contain more than three parts. When it does happen, it happens all the time and I have to implement workarounds for the issue. Even separating the union and reforming it does not correct the issue.
Although I could be wrong, holes that are fully enclosed or mostly enclosed seem to suffer this issue. Outside areas for shaping the part such as cutting off an outside corner doesn’t seem to be affected. The attached file has openings and a corner cut to demonstrate this.
Note: I run with all plugins disabled.
It happens in my game when I make union from parts where I need a non-standard shape. It also happens with the part in the attached place file. This happens in both Studio and on the live game server.
This has been happening since I started developing on the platform, just over a year ago. I don’t know when this started happening.
Pictures that show me standing on the hole and not falling through.
Video documenting the issue.
robloxapp-20230411-0133272.wmv (6.3 MB)
This screenshot shows the floor material property while standing on the opening.
The steps to reproduce this issue in the included file is very simple.
- Load place file.
- Jump on the part.
- Walk on the holes.
I currently have the
CollisionFidelity set for
PreciseConvexDecomposition so the area of the block on the hole is small, but it is there as one can see in the attached visuals above.
Engine - Union Collision Bug.rbxl (43.8 KB)
None, other than I have ran into this quite a few times, and performing a forum search, other developers are also having the issue.