View Full Version : Bullet Clothing Woes

03-16-2018, 11:29 AM
So I have this complex outfit that almost falls correctly except I can't figure out how to get the skeletal deformations to affect the bullet dynamics simulation. I want the body to morph via bones and for that movement to affect the outfit. What happens is that once dynamics is enabled the body sort of drifts randomly about ever so slightly and the morph that worked before disappears. I can't figure out how to change subdivision order level on this version of lightwave. I suspect the issue is related to whatever I am doing in the objects panel.

Anyway. So the outfit is in 2 layers and they collide with the mesh which is in a 3rd layer, all 3 are set to "deforming" in bullet, and I believe the clothing will behave properly once I get the skeleton deformation to show up in the simulation. If anyone has any tips for how to do this in recent lightwave, I would greatly appreciate it.

Edit: Okay, so it appears I have things working relatively smoothly, I just have to waiiiiit for the calculations to finish, then do some renders and then since there is so little payoff for a thread where someone solves their own problem, I will post the end result for any of the onlookers. I'm embarrassed to have posted a thread but I've been fidgeting for days with this outfit so I kind of hit a wall when the thing started floating around like a ghost. Well it's almost done. Later today I will post a render

P.S. I thought I should mention that this is my first post after 16 years of lurking on the forums. I made the plunge into actually owning software <3

03-16-2018, 02:17 PM
Sorry Sophia. I've been away for a week and haven't fiddled with bullet clothing and the new version yet. But since I will be at some point in the future I'd be curious to see what you figured out.

03-17-2018, 09:33 AM
First, welcome to the Insanity! :)

Just some general tips:

You'll want to set Shape Lock on all your layers to Position and Rotation, so the bone deformations affect the simulation.

You also don't want to set shape retention to 0% - strange things happen then.

If your body mesh is high poly or subdivided, you might want to use a low poly collision hull.

Also, you can't have multiple layers using each other as collision items; ie, you can't have clothes, body, and hair all interacting with each other. You'll have to simulate the first, bake it to MDD, and then run the next layer through bullet.

03-17-2018, 05:27 PM
You also don't want to set shape retention to 0% - strange things happen then.

Hey Kryslin,

Does this still apply if you are using a Gradient Texture and a Weight Map on Shape Retension?


03-17-2018, 06:28 PM
Yes it does. 0% Shape retention leads to your deforming object not retaining -any- shape. Usually, 5-10% is low enough.

03-17-2018, 09:38 PM
Yup, everything everyone said could have been useful like... 48 hours ago ^_^. Damn... well, I usually check these forums and then bang my head against a wall so it's nice having an account for a change!

Oh, and for wyattharris, what I figured out is that there's now this modifier stack for objects where you set the subdivision order by moving "Subdivision" down in the list. Specifically I had to do a little more and set the order to (Bones/Dynamics/Subdivision) before the bones affected the morph. Also, yes... Kryslin, I realized pretty quick (though not quick enough) that I had to simulate them seperately. I exported to Alembic, but I think that's because I read it is new and more modern. I am familiar with MDD and would probably have better luck getting the new collisions to hit the old layers. So far it doesn't matter much since the top layer goes through and sort of blends with the bottom layer, but if I want to get the neck detailing right, I need to overhaul a part of the clothing mesh to get the folds of the collar to flow into the hanging cloak thingy. I think I could get away with setting the collision distance of the cloak a little higher and then adding a little collision object in the front to prevent the apron from hiding the ribbon and cross. Anyway, here's a minimally edited render (did some touching up with clone stamp to erase a glitch with the collar). I plan to do a final pass at the geometry of the hands, the hair, the texture, eyelashes etc and then trying to fix some issues with shadows.


By the way, for anyone wondering "where have I seen this before?" it is a beloved Xenogears (1997) character, which would make this work a piece of fan art based on a character named Sophia. I was going for a cartoon style and then switched to a kind of oil painting look due to the in-game reference to a painting ^_^.

03-17-2018, 10:14 PM
I decided to be more generous and share more angles.

Here's some renders where I don't change anything, just hot off the press. You can see the garbled collar. That is from a weight map gone awry. There are also supposed to be more shadows on the front of the outfit from the cloak, but it actually passes through the mesh in several points. It just is all white so you can't tell! Haha! I win!


I'll fix it tomorrow -_-




I was almost so lazy as to only show you folks one image. Hah! Sorry.

03-18-2018, 10:57 AM
So it appears I can't edit my posts the next day. D'oh! Sorry about the triple posting.

Kryslin, it's interesting you mentioned shape retention. I spent about 10 hours this week trying to find the sweet spot for this parameter. It seems anything from 1% to 3% is tolerated well by my mesh, but anything else ruins my scene. At least with the upper part of the outfit... I am actually going to try to volume scale the dress to about 60% today and see what the tolerance level is for shape retention then (right now it's at 70% volume and 1% retention and the dress sags too much).

I will edit my post to share my results with anyone who is interested in saving time on future projects. I'll give a whole rundown of my weight maps and clothing parameters with screenshots... I feel like documenting things will only serve to help others with these pesky parameters! That volume conservation thing is a very risky parameter in terms of things messing up right at the end of simulation. I'm sure you can attest that changing any parameter in a simulation that is somewhat functional already is a huge risk if you are running on a slow machine and all the errors seem to show up at frame 450 or 500 or so -_-

For those of you that work professionally in this industry, how much time is budgeted per outfit? I would like to soon transition to being employed in 3D, and want to see how good I need to get at outfits to really be a viable employee. Outfits and hair seem to be something I really enjoy doing... I have spent a whole week on just an outfit so far, fine tuning, etc. It's kind of embarrassing at this point that I'm still fiddling, given each sim takes about an hour to run (per layer) on this mid-range 2017 laptop (my rig died recently...).

Oooh, very important technical question. HOW do I turn a single frame of an MDD into an object so I can resume a sim from frame 0 on already simulated material? Every time I try to get an object ouf of an MDD I end up with problems, because I can't seem to find good online tutorials about it. It would save me from having to Simulate up until frame 500 repeatedly to make sure _that one polygon_ doesn't jump out of the mesh again and again. It seems like this would be a useful feature to add, if it doesn't somehow exist and I've overlooked it.

Anyway. One question you fellow LW users can help me with is actually animating hair. I've done it before by creating a weight map to roughly hold down the roots of the hair, but... I am curious if anyone knows the best method of selecting ONLY the root points of the hair guides I have created in Z brush. Manually selecting them is way too tedious... I can't drag select without getting extra points in the selection. Hmm. I guess I've got my day planned out...

03-18-2018, 07:17 PM
Okay, so I am getting the impression that double posts are not so important to the moderators here...

Anyway. I was unable to edit the prev. post so here are the settings images. The cloak is set to blue purely so you can see the two seperate objects. In early renders the shadows showed up correctly, but because I hadn't properly scaled my project I had to redo all the settings once I decided to not work with meters anymore... -_-. Chalk it up to laziness.

<Image 1 = Dress settings>


<Image 2 = Cloak/cape settings>


<Image 3 = Character settings>


<Image 4 = Settings for an extra collision object which is invisible, meant to keep the ribbon from getting hidden by cloth>


<Image 5 = Weight maps for both the cloak and the dress, which are in separate layers>


There's some problems with the weight map still on the cloak causing some geometry to bounce around due to the self collisions, so I need to set a few vertices to 20% weight map or so but anyway, the settings are all finalized for Bullet except I am going to still try to alter the volume conservation/stiffness/shape retention parameters of the dress slightly to get a little more tight to the skin. That's for tomorrow. For now the settings are pretty good for any noob lurkers to get started with their capes and cloaks.

I know there are DEFINITELY a bunch of lurkers on this site seeking tidbits of advice, since I used to be one for years... From experience, I know many are probably on the fence about purchasing and so: Hey lurkers, buy a license, it is worth it! I wish I had bought sooner...