Humanoid HipHeight does not work with unknown collision groups

If a humanoid’s HumanoidRootPart has an unknown collision group (i.e. copied from a place where the collision group was valid), humanoids will treat the HipHeight as 0, regardless of what it’s set to, and sling off of the map.

Repro.rbxl (22.8 KB)

Left: unknown collision group; Right: default collision group
https://gfycat.com/FrequentChillyGreyhounddog

If HipHeight is 50, the HRP will still be on the ground if it has an unknown collision group. If the HumanoidRootPart’s collision group is changed to something valid, this issue is resolved. The slinging off the map only happens with unknown collision groups – setting HipHeight to 0 with a valid collision group does not reproduce the issue.

3 Likes