I was trying to make a setup where my character was falling (with an animation), and gradually blend to ragdoll from Pelvis and down using “Set All Bodies Below Simulate Physics” (“Pelvis” as Bone Name). However when i do that, he starts to go into a crazy spin. I’ve even checked if it still happens if i turn off all collisions and still the same. And this also happens inside PhaT if i play with the “Physics Blend” setting. I’ve got all bodies set to “Default” for Physics type btw. Is that wrong?
When simulating physics it uses the Physics assets for collision as you are aware. In order to get it looking and feeling right you need to tweak the Physics asset extensively to make it right. If you are using your own it would have created a Physics Assets automatically if that’s the case what you will find is that the collisions are overlapping each other causing crazy movement also you will see there is no constraint on any of the bones so every bone’s collision box can twist and turn and swing and every direction, 360 degrees. You need to play with this to make it look and feel right… (i.e limit the angle the torso can swing, twist and turn)
You can always have a play and simulate it in the PhaT tool to show you the results. I did it for one character and got it quite nice but then we changed (which sucks cause it does take time to get right)
Good luck
Hi Conkerballs,
Gotta love that name haha. Anyway… i tried this with the ThirdPerson Example, where the Epic dudes have already done a lot of tweaking on the bodies. I have tried to modify the collision-bodies so none of them overlap, and he still makes the crazy-spin. Im pretty sure it’s something else.
I might add that it looks ok if it set simulate weight = 1, but it’s only when i change this to a fraction between 0 and 1 it gets funky.
i’ve posted a video showing what i do and what i get: - YouTube
Hope someone can spot what im doing wrong? The video is from 4.11.0 Preview 3 btw, but also tried this in 4.10.1 with same result.
Hi Aloneball,
I did watch the Youtube video and tried testing it exactly as you done with a multitude of different variables and I was getting the same response.
The video cleared up exactly what the issue is, my previous response was a bit irrelevant haha.
I downloaded the content examples because there is examples in there for Physics based Animation and the example works flawlessly for them and I believe the issue must reside in either the movement component or the Capsule collision because when you just put the skeletal mesh in a level and force it to use an animation asset not a blueprint it works fine.
I am unsure how to assist you further but I will up vote the thread to hopefully increase the visibility of your issue.
Ok, so you were able to reproduce my spinning mesh behavior, is that correct understood?
When im home tonight i will try download the content examples and see if i can see what they do different there.
Anyway, thanks a lot for testing this out too.
So i’ve just come home and done downloading the ContentExamples for 4.10.1 and i see it’s working for the upperarm_r, but that also works for me in the ThirdPersonTemplate. If i change the ContentExamples to use the pelvis, it goes into a spin too… Can you (or anyone) reproduce this?
I can reproduce this… I wonder if it’s bug and it’s doing something directly to the root bone… Would be nice to get an official response on this or maybe post a bug report.
Thanks for checking up on it. I’ll move this to the bugs section and hope some from staff will spot it.
Hey Guys,
I wanted to let you know that I’ve got an email out to one of our devs about why this is happening. Something tells me that you’re simply not supposed to do this, but I’m going to find out if that’s true and why.
-.
Thanks a lot , i’ve been doing a tutorials series on ragdoll today, and in the last episode i mention a “workaround” which involves adding a root body which use “Kinematic” setting. This eliminates the spinning, but still does not really produce a satisfying result. However, this might be because it is built to be a quick transition or because i’ve only played around with it in PhaT. The video is public here. Feel free to pass that along too. Ragdoll 101 - Part 4 A few words on full body blend between animation and physics - YouTube
Hey aloneball,
In talking to one of our engineers, he’s telling me that this feature isn’t really designed to be used in a manner where a skeletal mesh stays at 0.5 or 0.9 blend weight for any length of time. It’s meant to provide a smoother transition from 0 to 1 and vice versa, but not to linger anywhere in the middle. He did mention that this feature could use some work, so in the future it might be better suited to handling blends for extended periods of time.
-.
Hi ,
Thanks for getting back on this matter. It is kind of what i expected after experimenting a bit too. I will keep experimenting a bit with the current implementation though, since it does seem to hold some potential to do some interesting stuff besides a smooth transition.
Also i think my confusion on the usage with a fractional value on the entire comes from the content examples where it demonstrates the use just fine with a slider on only the arm (if i recall right). To avoid further confusion/making it more clear, a note about not using it like this would probably be a good thing.
Again, thanks for the good work you do.
/Jonas