[question] question towards Ik and self collision/penetration

hello guys while i do know so far which the big topics in unreal 5 so far are lumen and nanites, i have something which aways bugged me in unreal 4 and i would love to get adressed in unreal 5, which is the "self collision/penetration, it’s a issue which i would like to know if unreal want to adress in unreal 5.

since unreal ie going with the control rig and full body ik solver and it’s working to "interact with the “world” i want to know more when “interacti with self” or when interacting with others characters, i means the “adaptative animations” for exemple the classic “fat character” i have a walk animation with was made to work with a “non fat character” then instead of have to “edit the animation” to not penetrate in the character body due to being fat, if unreal is adressing it like this:

for games where you can edit characters in real time or for when a character is wearing “high heels” i can make the body “adapt” for the new angle feet or when the character is crossing arms it will work for different type of bodies insteand of create different type of animations for the character, any chance to have it adressed???, a way where using ik the animation will auto adapt to avoid self penetration and maybe in future stuffs like when you “sitting in a chair” you can do the same animation for different sizes of chairs.

currently looks like unity can already adress those stuffs then i would like to know if is on the unreal plans to also adress it and give us way to auto adjust any animation without need to create any new for those issues, like the same walk animation or idle animation can be used by any character as long they have the same bone structure and it not make any self penetration issue and stuffs like that.

i way to make the character mesh be able to collide with self and react to it in the same way it could react with objects in a realistic way and adapt to the body different forms.

also any plans to improve how physical collisions works? make it "more belieaveble, specially for stuffs like cloth or body physicis like gigles, because for exemple for cloths the capsule still a lot trick to work because the cloth sometimes can find ways to clip throught the character mesh because of the capsule editing limitations???

any plans to improve those aspects???


same question here :sob:

Answer is physical animation, I managed to create a self clipping setup in few steps.

Rigel Self Clipping avoidance

wow interesting any chance to release the pluging into unreal market???, it’s really looks interesting.
also it’s already compatible with unreal 5?

As of now the plugin works in UE5, but I’m refactoring the entire setup specifically for UE5, including some of the new tools available.
Since UE4 version as of now has some dependency ( which I’m removing for UE5 ) I can’t submit the plugin to the market place.
If you’re interested in the plugin, I have a standard and VR demo that you can try ( make sure to setup the tracker roles ), where you can check all the features available ( including self clipping and realtime smoothing )

thanks for the replay, well i will give a try on this test later, due to the pluging being a little “too expensive” for me i can only maybe buy it after it goes to the epic market because on that it have some payments which maybe more “possible to buy it”.

anyway so far the most important feature for me is the self collision, because it can help a lot adjusting many animations fo different type of characters without need to do the manual work all over for every character.

Can you briefly say the idea, is it a way to calculate the position of the offset?

Physical animation takes care of avoiding clipping using physics capsules while also taking into account the skeletal animation.
If the animation is about to clip, the capsules avoid this behaviour.

one question this project can be used on characters with "morphs targets, i means characters like where you can customize like making it more fat or big boobs and those stuffs, it can be worked to take it into account?, like if i make the character more fat then the collision will adjust itself to make this type of character behaviour right and all those stuffs? or it’s only for "pre-made characters?

Nope, as far as I know collision capsules can’t be changed at runtime, so you would have rather use preset collision assets that will more or less match with the morphs, but nothing at runtime.
Not sure if you can change the capsule transforms at runtime via code.

this is a issue, because this is one of the things which i was mind, because my plan was to make a “custom” character then from this being able to generate different characters and use a real time collision to make sure the same animation will work don’t matter what is the type of body, the collision would adjust itself based on the collision capsule transform like if a increase the breast size the then "breast capsul also adjust it’s size based on the breast slide, or a fat slide having the collision capsules adjusting themselfs with others target morphs.

to avoid start a new topic here something i saw which i would also to lve being adressed which is almost the same but more related to cloths and being able to make layers of outfits which would be really awesome

but still related to the main topic, i really feel would be good if unreal team start to work more on “self collisions” because it’s really would help a lot to improve the realism.

Hello, can this plugin be used for animation files (like .fbx), or the animation produced by characters in game?

Hi, I saw your other post related to the character collision.
The self-clipping feature added to my plugin, as mentioned above, is based on physical animation and it works for realtime animations ( using the Vive Trackers ).
You could use it for recorded animations, but you would simply take the setup and use it in a separate BP.
On my youtube channel there is an explanation on how to do the setup, so I think you can end up with the same results as my plugin if you follow that.
Since is based on physics, do not expecy miracles, especially with fast movement, since physics can go crazy and you’ll end up having worse results sometimes, but it does work most of the time.

Hi @Enter_Reality ,

Your plugin looks awesome !

I’m trying to implement the “self clipping avoidance” feature myself but I’m stuck in the middle of it.

I did not find a solution to simulate the physics on the arms of my avatar (to detect collisions) without making a ragdoll effect. The arms do not keep the position set by the animation.

Moreover, I’m not sure how/when I do have to start simulating the physics. I suppose it must be done only when a collision is going to happen, but how do you know that ?

Thanks for your time.

Best regards.

Hi @BenV , as mentioned in my previous post, you need to use physical animation for the collision setup to work, not just “simulate physics” triggered from the BP.


I’m following this documentation.
By “simulate physics” I was referring to the ** Set All Bodies Below Simulate Physics** node that I apply on the arms of my avatar in my case.

Yep, you’re on the right track, just test different values and you’ll find the sweet spot for the physics to work as expected