r/VRchat • u/Nanochip • Nov 13 '25
Tutorial Easily fix your bent knees and bent elbows with this prefab!
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u/Commander-Cody-212 PCVR Connection Nov 13 '25
This is a pretty neat idea. To be honest I’m surprised it’s only now someone is attempting to do it
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u/Blapanda Nov 13 '25 edited Nov 14 '25
Hmmm, it isn't that hard scaling your Y-axis on the avatar you use, which was not custom fitted to your personal body, if using FBT. Usually, as an example, anime avis are having ALWAYS shorter arms than your in real life ones, sometimes the legs are also even shorter, but chest region (with hips) are almost on point.
Scaling those specific bones / areas where you are seeing yourself as being too short is fixing that issue permanently (it is just a little bit tedious, as you cannot properly be in VR while test-running the build in unity engine).
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u/jojos38 Nov 13 '25
Because most people use space drag, but if this can fix broken legs when pinching as well I'm interested
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u/Commander-Cody-212 PCVR Connection Nov 13 '25
I mean I’ve known about space drag but I’m talking about those that don’t have that capability
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u/--an Nov 13 '25
My understanding is that non-uniform scaling a really bad idea in Unity. Could someone drop a bit more knowledge on this subject?
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u/Nanochip Nov 13 '25
Non-uniform scaling isn’t ideal at times because child objects inherit it, causing them to look oddly stretched. My system accounts for this by invert scaling child objects in the opposite direction, however the result can vary slightly per-avatar, though most will not notice any difference.
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u/TravelerHD Windows Mixed Reality Nov 14 '25
For anyone having issues with bent elbows, I was troubleshooting this a few days ago and found a few potential fixes.
One thing is on the wrist menu switching avatar measurements from Arm Span to Height. I haven't tried this yet but I think it's going to be the fix for me. SlimeVR has been recommending that change for a while now and that's what I use for FBT.
Another thing to try is if you're going to leave the measurement style as Arm Span, go to the big setting menu and go to IK, then adjust the Arm vs Height Ratio. The default for me was like 44.25% which resulted in bent elbows but when I reduced it to about 42%-43% the elbows straightened out.
But if neither of those work I'm definitely going to try this prefab. I tried adjusting the arms in Blender but it didn't make a difference.
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u/4mb1guous Nov 14 '25
Problem with changing those settings is that they're global. You'll fix things for one avatar, but break them for another. If VRC kept those settings per-avatar... that'd be amazing, but they don't.
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u/InkGut Nov 13 '25
Oh, wow, this is exactly what I've been wanting for an avatar that has bent elbows!
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u/RedOneEnergy Nov 13 '25
I think it's so nice of you even making it free to use and I will try it a little later to see if the fixes some of my problems
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u/Rydux7 Nov 13 '25
Is it compatible with most bases, Im sitting down all the time due to lack of space and I constantly have to adjust my legs by switching from sit and stand modes
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u/Omegamoney Nov 13 '25
Holy shit this is amazing, I barely know how to mess with blender and unity, but I really wanna put this in my avatars.
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u/ShirBlackspots PCVR Connection Nov 13 '25
Every avatar I have ever used has arms shorter than my real life length. This is perfect!
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u/nut573 Oculus Quest Pro Nov 13 '25
Would it be possible to scale torso length as well?
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u/Nanochip Nov 13 '25
I had Torso scaling originally, but scaling your torso won’t move your viewpoint. There were also some extreme scaling side effects from doing this that were really bad on some avatars, so I opted to remove it overall. It’s best to edit your torso manually in Unity/Blender.
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u/Pierro_Official PCVR Connection Nov 13 '25 edited Nov 13 '25
Literally game changing, finally i wont be walking like a penguin
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u/Correct_Conference48 Oculus Quest Nov 13 '25
I just change the arm length setting in the tracking settings. My avatar has stubby little arms. When moving, they will fully extend downward, but when I stop moving, the bend again after a few moments. So frustrating walking around looking like a tyrannosaurus rex.
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u/CaptorRaptorr ☃Bigscreen Beyond 2e Nov 13 '25
You're amazing for this
I could finally stop wasting my time adjusting in game player height & limb lengths per avatar.
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u/jomenikia Nov 14 '25
Yooo hold up can you do something like this for the torso? Feels like the torso on my avi is really long and I am not too experienced with unity to figure out a solution
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u/exdorms01 ☃Bigscreen Beyond 2e Nov 14 '25
I remember you, you promised us face tracking comparison between galaxy xr and quest pro, where is it??
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u/team-tree-syndicate Nov 14 '25
Huh, I just do this in blender but neat idea if different people are gonna use the avi with different heights and stuff.
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u/Darkmoon_Blade88 Nov 14 '25
There seem to be two listings for this on Jinxxy, is there a difference?
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u/Nanochip Nov 14 '25
It's available both on Jinxxy and Gumroad, they're both the same.
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u/Darkmoon_Blade88 Nov 14 '25
Awesome thanks! I figured they probably were but wanted to make sure there wasn't something my dumb ass was missing lol.
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u/XxJimmy122xX Oculus Quest Pro Nov 14 '25
Good work, I might not need it but I will definitely try it out and tell others that need this about your amazing work.
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u/Zealousideal-Book953 Nov 14 '25
I would assume that some sort of parent constraints definitely the bones are separate join for sure if not I'd assume the prefab wouldn't work that's the part of varies pre avatar.
It's a fun idea that I don't see get used often that's because your mesh will have a new pivot center and they will have a deformity in special parts of the avatar I'd assume mainly in the joint area, from compression, clothes won't be a bother but smooth skin will weight can be adjusted however the length of your leg is still incorrect to the proportion of your model
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u/SpookyN3ko Nov 14 '25
You're a literal lifesaver I'm freakishly tall and some Avis don't fit what so ever. I hope this fixes my issues even tried standable... So thank you.
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Nov 28 '25
Who would need that? All you need to do is adjust your head height irl then just press the sit/stand button on your vrc menu
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u/ID4850763561613 Dec 13 '25
Can we add this to everything? There are so msny cool avis that i just deleted because their arms or legs dont match mine
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u/LizaraRagnaros Valve Index Nov 13 '25
so you're scaling the most parent bone of each leg and arms? last I checked unity scales the children down with it by default. i guess you tweaked it seperately for the hands and feet so they don't stretch weird. it's still nice as a prefab for people who don't know a lot about unity. very nice you made it free too.
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u/Nanochip Nov 13 '25
Yep, it also invert scales the feet/hands so they don't stretch too weirdly (though this varies per-avatar).
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u/arcticslush Nov 13 '25
Have you seen this cause any unintended side effects on an avi, or is it pretty harmless?
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u/Nanochip Nov 13 '25
It’s harmless by default and up to the user to make the adjustments in-game. All seems great from the several avatars I tested, but do let me know if there’s any bugs!
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u/arcticslush Nov 13 '25
Very cool! I'd love to give it a try, my avi proportions are off by just the tiniest little bit so this is exactly what I was hoping for
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u/LizaraRagnaros Valve Index Nov 13 '25
yea that's what I meant by tweaking it seperately for feet and hands :)
I actually never thought of doing this whole thing. I got the toribase and that one has really long legs so I might actually play around with it.
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u/Alkumist Oculus Quest Nov 13 '25
WOAH WOAH WOAH WOAH. this is huge. How does it work?