MD Dress Drape Test

Little proof of concept of my 18hr laborious research into the intricacies of using Marvelous Designer to drape cloth accurately and render it in Unreal Engine. This is the CC3 Toon Character with a demo dress from MD. I used USD to transfer the animation, but it's super messy to render in UE, and I feel there has to be a better way. Alembic to UE didn't work well, but perhaps there's hope for next time.

I'm very happy with how the cloth drapes though. Let me share some of the issues I've had in putting this together.

The "messy" part in Unreal Engine is that the USD file from Marvelous Designer doesn't produce a tangible animation. We open the file using the USD Stage Manager, which will display the assets contained in the USD in our viewport. There is a "transient" level sequence that will produce a usable sequencer, but nothing you add to it is saved back to it. I guess transient in this context means it doesn't exist as a file, and there was no way to turn it into one. There is an option to import all assets from the USD file into the project, which takes forever, but does not import the actual animation. That's the downside of "beta stuff".

To add my character animation and the cameras, I had to use a sub-sequence and attach it to the transient USD level sequence. This wouldn't be so bad, but next time I open the UE project, none of these changes persist and I have to attach it again. Furthermore, when I render the sequence out, the level sequence disappears and needs to be re-opened again (and I have to re-attach the character/camera level sequence). This would never work in a production pipeline.

Something else I had trouble with was to remove the arms from my figure after animation, so they wouldn't interfere with the cloth drape in Marvelous Designer. In a recent tutorial by Reallusion, they do exactly that: highlight the extraneous sections of your figure in Character Creator, hit delete and boom: arms gone. Clearly works in their video, but not on my system. What gives?

I've filed this as a bug report, and Reallusion very kindly got back to me with the answer to this puzzle: we have to turn a CC3+ character (on which removing faces isn't allowed) into an ActorCore figure to make changes. They even made a little unlisted video for me, how nice is that? I might expand this into something with narration when I get a chance, so I won't forget.

As good as the iClone/CC combo is, it certainly isn't without issues. Trying to export the first frame of the animation from iClone in the exact pose of the animation doesn't seem possible, so I've imported the FBX into Blender and exported the first frame from there. This is necessary to build the clothing in Marvelous Designer.

Blender has become my invaluable Swiss Army Knife for anything I do. Whatever other apps lack or can't do, Blender most certainly has a solution. It might not be the most obvious, but it's always been there to help me out. That's why I'm one of the 2% who give to the Blender Development Fund and Blender Studio to support their work. Thank you, Blender!

The easiest part was actually the cloth draping inside Marvelous Designer. I've picked this in-place animation because forward motion can introduce some issues, and I only wanted to test the conceptual workflow before tackling anything more difficult. MD has become so much better in recent years, compared to the first version I've tried in 2014 (although MD4 was already very impressive back then).

Today we have several outfits that come with Marvelous Designer, the modular configurator to make your own clothing fast, proper UV packing and of course auto fitting. This makes it super easy to import a new avatar, then have MD calculate the fit for a different body shape without having to alter the patterns manually.

Once I had the dress fitted on my figure in her A-Pose, I was able to bring in the armless FBX animation and start simulating. Marvelous Designer is one of the few applications that can calculate cloth collision directly against the high-res figure mesh. This is important to note because both iClone and Unreal Engine don't have that ability at the moment. Those rely on separate collision shapes that are excruciating to setup and use, and never look quite right. It's done for performance reasons, but I can't see myself using them for animations.

Accurate cloth drapes on animated characters is really why I've invested so much time on this topic. Al