Why is my apex cloth penetrating the ragdoll?

Greetings, I’ve been tasked with learning APEX for cloth simming and was moving along swimmingly till I reached the generation of the body ragdoll. The purpose of the ragdoll is to prevent the cloth from intersecting/penetrating the body mesh, and on most parts of the body it does so. I have one area though, the right thigh where it is ignoring the ragdoll.

I’ll attach the pictures that describe the situation. The clothing is a dress, with a moderate drape skirt section on the left, and held in place with a strap on the right. Currently the strap will drop right through to the middle of the leg though. How might I fix this problem? I assumed that a ragdoll would stop cloth intersection so any cloth painted with high weights would collide with or hang on a body’s shell or capsule. I weighted the strap very high so it could move very easily on the thigh, but is that making the conflict?

For additional info, none of our models and clothing was designed with APEX in mind, we started with a different engine and did traditional skinning before moving over to UE4 and experimenting with APEX. I can provide the info on the settings I used or pics of the weighting if need be. Oh, and the entire dress is essentially a plane, rather than double sided, if that can cause problems.

Any help would be greatly appreciated, thanks for your time on my behalf.

Some more info: When I switched the ragdoll generation from convex hull kinematic to capsule kinematic, the cloth sim obeyed the ragdoll collision. I originally avoided the capsule type because resources weren’t an issue and because the capsules generated, even with inflate at 0 were far larger than the body parts.

I attempted to follow one of the video tutorials, but it must be an older one because I had no option for shrinking or expanding one end or the other of the capsule - only uniform scaling of the whole thing.

Clarification on the proper setup and use of the convex ragdoll system would be very useful, and if I missed it or if it’s hidden, the way to scale the ends of capsules independently would also be spectacular enlightenment. Thanks again for any help rendered everyone!

Since no answers yet, figured I’d narrow the scope a bit. So the primary overriding question I have is why does the cloth ignore the convex hull ragdoll shapes but not the capsule. All other settings are exactly the same, but only with capsule ragdoll does the cloth obey collision.

Could it be that there is too close a distance between the bind position of the cloth and the ragdoll shell?

Hi Stormtempter,

One of our more prolific community members, Fighter5347, has a video showing the basics of Apex Cloth.

Video Here

I’m not that familiar with Cloth at the moment but in Fighters video he’s setup a kinematic rig to have collision with the character it’s attached to. With this he is able to change some settings that will affect how much the cloth intersects with the character mesh.

Let me know if this helps, if not I’ll see what I can learn about Cloth to help you out!

Thank you!


Thanks for the reply! It might be a few days before I can get back into Apex, but I will definitely take a long good look at that video and see what I can do and report back, thank you for finding it.

Hi Stormtempter,

I’ve marked this as the correct answer for the moment for our tracking purposes. If you’re still having the issue please post back here and I’ll take a look at it! :slight_smile:

Thank you!


Hate to do this, but I’m necromancing this question. I did watch the video those many months ago and went with capsules for collision, it sufficed for awhile. Now we’re needed more accuracy and I went back to trying the convex hull collision with the same results as last time - the cloth drops right through it.

I’ll go back to using capsules and doing my best to make it work, but if you’re able to investigate the convex hulls and let me know why they aren’t working or what I could do to make them work, lemme know, this is very vexing, lol.

You may want to take a look at Nvidia’s official tutorials.

Particularly the ones with the Cape and the Trenchcoat where backstop is being painted onto the cloth. This can help limit the cloth clipping.

I followed the trench coat without figuring out the convex hull. I’ll take a look at the Sport Pants and the others in case something was missed.

If it makes a difference regarding convex hull specifically, the cloth on this character is planar, it has no thickness.

I have the same problem, and it seems that convex hulls are not handled by UE4. Looking forward for a solution.