Rigging & Skinning for interchangeable meshes

Vectroid

Hi guys,

I have a few years of experience modeling in 3ds Max but I am now being presented with a new challenge and I'm not quite sure where to begin with it.

I have done some character modeling and rigging in the past for single characters with no customization options but this time, I have to model and rig an avatar system (male and female) with interchangeable meshes for clothing. I have never done anything like this before so I thought it would be nice to get some pointers from the pros.

So let's say I have a character in 3ds Max with everything separated in a modular fashion (head, upper clothing, bottom clothing, shoes all separated).
- Would it make my life easier if the body was fully built beneath the clothing or would you build the clothing merged with the hands for example?
- Is the best way to transfer skinning information across different clothing meshes of the same type (e.g. pants) by applying a skinning wrap modifier then converting it to skin?
- Would you transfer the male rig information to the female rig or would you treat them separately?
- When exporting, do you have to export the clothes as pieces with the bones along with it?

Sorry if these questions have been asked before, I found it surprisingly hard to find information about similar situations on google. Thanks in advance!

Mark Dygert

Vectroid wrote: »

- Would it make my life easier if the body was fully built beneath the clothing or would you build the clothing merged with the hands for example?

I'm a little confused by this, are you asking if you should have a base character mesh and apply clothing on top of the base mesh? Having two meshes like legs and pants representing the same thing seems like a waste. If you're going to have pants and shorts, then model the legs and the shorts together as a new "legs module"

Vectroid wrote: »

- Is the best way to transfer skinning information across different clothing meshes of the same type (e.g. pants) by applying a skinning wrap modifier then converting it to skin?

As long as the meshes are roughly the same size and shape that's a smart way to do it.

Vectroid wrote: »

- Would you transfer the male rig information to the female rig or would you treat them separately?

It depends on how similar the models/rigs are. In a lot of games they share the same base components and its things like clothing style, animations and hair/face options that turn the avatar into one or the other. But that depends on what design and the tech guys have worked out.

Vectroid wrote: »

- When exporting, do you have to export the clothes as pieces with the bones along with it?

That is very engine specific and those systems aren't universal. Typically it's whatever your graphics programer tells you to do. I've seen some systems where you export just the mesh with its skin weights, Animations are stored in other files and exported separately then it all goes into a big pot, a programer sprinkles his/her dark magic in the mix and it all comes out on screen.

Vectroid wrote: »

Sorry if these questions have been asked before, I found it surprisingly hard to find information about similar situations on google. Thanks in advance!

That's mostly because it takes a fusion of an artist sitting down with a programer and the designer and they all work out a solution. There isn't really one specific way to make it work and it often is so proprietary that the info is of no use to anyone outside of the company =/

But in general you've got a pretty good handle on the art side, you just need to sit down with the other members and get something that works and isn't going to end in murder.

Vectroid

Thanks for the reply, that definitely cleared up some of the mystery behind this process

I'm a little confused by this, are you asking if you should have a base character mesh and apply clothing on top of the base mesh? Having two meshes like legs and pants representing the same thing seems like a waste. If you're going to have pants and shorts, then model the legs and the shorts together as a new "legs module"

I was thinking it might have been a good idea to have a base human body and clothing on top so I could transfer some of the skinning data through the skin wrap easier but I see your point. I think it would be a waste in terms of polys.

That is very engine specific and those systems aren't universal. Typically it's whatever your graphics programer tells you to do. I've seen some systems where you export just the mesh with its skin weights, Animations are stored in other files and exported separately then it all goes into a big pot, a programer sprinkles his/her dark magic in the mix and it all comes out on screen.

This is the part I was completely unsure about. I'm working with a modified version of the UT2004 engine and I was not sure if its exporter is exporting bones and skinning data separately or just using baked animation keys. But what you said makes a lot of sense.
I'm freelancing so I can't bug the programmers directly and sit down with them but it looks like I'm gonna have to find a way to bug them to be able to design this in an efficient way.

Thanks again for the help! Very much appreciated!