Bundle combinations break games

Title says it all. A friend of mine (@dudemanextremer) recently pointed out that all limbs from the Rthro collection have a different mass - even if the game is set to R15 and not Rthro.

I took a look under the hood, and these limbs have different sizes + position offsets without the mesh.

This causes issues with things such as gravity, jumping, and hitboxes.

So I ask - is this intentional?

(underneath a non-Rthro head)

(underneath an Rthro head)

(another Rthro head)

(yet another Rthro head)


I think the size is for the mesh itself and the weight may not make a relevant difference in the gravity / jumping (I’m not sure how much of an effect it would make). I doubt it would be intentional but its actually quite cool how you’ve pointed this out. Hitboxes would be a big thing though.

Just did some testing:
It makes relatively no difference in the jumping by the look of it - the engine may compensate for it.

The one on the left is mirror Law who replicates my keyboard movements as a reflection (if i jump with the spacebar he will also do his idea of a jump). Mirror Law has a normal head mass. On the right is myself who has a head which is massless. From testing it seems that we both have the same jump height.

Hitboxing would be a massive difference though. Complainable I’m pretty sure some hats have larger hit boxes and using shoulder assets also increases your hitbox - therefore your hitbox may be off anyway. I doubt it was intentional and instead it was just an issue they overlooked.


The hitboxes is definitely a big issue.

You can use all of those doors with non-Rthro heads.


I mean a work around is to no collide the heads and then have a fake head in in order to act as the hitbox but I can clearly see your point - I think its understandable why the size is as stupidly big as it is (as to make the head look better on the person) but jeez if it can’t fit through a door then we’re all doomed if we ever start making more stuff using anthro.

I think the masses and gravity and jumping they just left out as it would have little noticeable impact but the hitbox is a big flop. Not too sure how you’d fix it though as its a mesh and it has to be a relative size anyway - as such it may not be a bug but instead just something which they couldn’t find a better way to handle.

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This isn’t even anthro, it’s R15 using pieces of Rthro packages.

The solution would be to change the part size to the same as the R15 counterpart and use mesh offset/scale instead.

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Apologies for my wording, forgot Anthro and Rthro are not the same thing (lol).

And I don’t work with meshes so I didn’t know you could offset/scale it so thanks for the knowledge. I do wonder why they didnt just do that originally - that must ruin a few games unintentionally.


This is literally something out of my control. I can’t stop a player from using Rthro parts in an R15-only game.

@Captain_Rando @RBLXImagineer

I talked to you guys about this at RDC, just wanted to tag you about it - these bugs are still a thing with the older Rthro packages.

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I have recently found an additional case where using various Rthro packages in places with set R15 avatar constraints can result in spawning way above SpawnLocations due to hitboxes.

Any word on this?


The best inconsistency demonstration I have found thus far. Yes - this is still an issue, it can break games and cause obnoxious inconsistencies.

Attempting to walk over a 2 stud high wall

Game Settings:

No Package:
As seen, it’s possible - there’s no stutters. It’s very easy to do.

Various R15 Pieces:
Borderline impossible, no indication as to why this would be different. The character’s hitbox is slightly different - that’s why it can’t climb the wall.

This is my last post on the matter to prevent further clogging of the thread.

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I have updated the title of this thread to include all bundles.

Any chance you could see if this bug is tracked somewhere @OuterspaceNemo?

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This is really annoying when it comes to gravity. Would like to see this fixed…

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This is an urgent issue, users are using some packages to get really small sizes (perhaps to avoid deadly things, such as gun shots, lasers, etc) and become harder to attack

Here is a example:

Without Hat:



There are even more combinations that allow you to get even more smaller

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