Giving dimensionality to objects like clothing so edges have depth (3d mesh to 3d "solid")


#1

Take, for instance, a short sleeve shirt where the outer edge of the sleeve can be seen against the arm. The goal here is to give the shirt a basic sense of existing in 3d space rather than being able to see that it’s a warped 2d plane at the edges depending on view angle.

I’ve picked apart a few models in c4d to see how othes handle this, and seen a few approaches.

Some, for instance, create extra edge loops, then offset them in toward the arm a bit, and fold them back like an inverted cuff so the viewer sees a slightly rounded 3d appearance to the edge of the sleeve as it disappears back toward the arm.

That’s more or less what I’m doing currently, but wondering if there’s a better option. For instance, is there a way to take a complex mesh form (using example of shirt), and create an automatic extrusion of it that extrudes not along an axis, but inward or outward depending on the contours of the object, then uses caps or bevels or something to define the thickness and edge characteristics? (create 3d “solid” from 3d mesh).


#2

Yes. there is exactly this. its called the Cloth Surface object. It is found under the Simulate -> Cloth menu. Create this and place your object under it. You can set the thickness as well as additional subdivisions of the mesh surface.


#3

Awesome. Thanks.

Makes perfect sense that it WOULD exist… just hadn’t seen any mentions of it in any tuts, and no idea what form it might take in menus.

None of the models I picked apart used this.

Is this possibly because of the different file formats? In other words, if you wanted to export a C4d object that used this tag, would it have to be baked into a mesh first?

Or, is it maybe considered inefficient like perhaps increasing poly count too much for animatable characters?

Particular reason one way or another would be preferable for characters destined for animation?


#4

Normally, you’d only give depth or “3D solid” on the edges of the cloth and not the whole cloth itself.

If you do so, you’re basically asking for trouble both in simulating and weighting. You’re basically going to unnecessary hell.

With that said, answers to your follow up question:
RE: In other words, if you wanted to export a C4d object that used this tag, would it have to be baked into a mesh first?

Yes, baked to the mesh first.

RE: is it maybe considered inefficient like perhaps increasing poly count too much for animatable characters?
As mentioned above, yes this is inefficient.

RE: Particular reason one way or another would be preferable for characters destined for animation?
Again, extrude only the edges.


#5

Looks like some of the models I picked apart probably were using such a deformer, and I just wasn’t seeing it since I was importing obj, fbx, etc.

What you’re saying mak,es perfect sense to me, but after spending a bit of time with it, I’m not seeing how it’s applied to edges only. Not clear if you’re referring to doing so with the Cloth Surface deformer or via some other process.

Perhaps I should just take a step back and ask the part that really matters ultimately:

What’s the optimal (and time efficient) way to do this for a character that is going to be animated?

I tried doing it a few ways manually as well, and can always make it work, but it seemed like a needlessly inefficient process each time.


#6

That’s why the Cloth Surface object is a generator. You work with the flat (2D) cloth in weighting and simulating, and the 3D thickness is added by Cloth Surface afterwards. For the comparatively easy cases, that may suffice.


#7

Maybe I should take even a bigger step back and ask in general:

Currently character has small (relatively) even spaces between clothing and body to avoid collisions on deformation. It currently has rolled (by hand) edges on sleeves, etc.

Am I understanding correctly that I’m better off undoing those rolled edges, and just adding the generator post-rigging?

The generator doesn’t appear to have any function for edges only, so just want to verify that I’m not missing something there.

Or… should I just re-evaluate the entire approach, and maybe do something instead like weld the sleeves to the arm, rig, and then use the generator post-rigging to add a positive extrusion to the shirt? (as opposed to a negative inward extrusion currently since there’s a space)

Asking in general so I can use best practices moving forward, but I am also currently working out the poly reduction for an existing character that already has spaces and hand (inwardly) rolled sleeve edges, so if it’s just a matter of preference, I can just leave him as is… but if it’s better some other way, I can fix him before he gets rigged.


#8

Be a little more general even, and think about what you want to achieve.

Easiest way is to treat the clothing as part of the body, instead of the actual body polys. You can add some wrinkles by painting them on a displacement map and control them by the angle of the limb. This works only for tight clothing like jumpsuits though, and easily looks fake. But since you can directly rig it and don’t need simulation, it’s probably fastest.

Then you can use full simulation - externally in Marvelous Designer, internally by Syflex or something, or if you’re brave you can use the internal Clothilde. This will give you the most realistic results (uh, depending on the tool) since you have physical simulation. But you can’t trick around with “rolled up edges” as these additional polys may jeopardize the simulation. You would use a single polymesh, simulate that, and add a Cloth tag later for the thickness. This may create intersecting polys but since the cloth is thin, this will in most cases not be visible.

Finally, you may want to have a character with frequent clothing changes but still no full simulation; in this case it is reasonable to create an (interchangeable) cloth mesh over a body mesh which is controlled by the body mesh instead of being simulated. So you would rig the body, and the cloth mesh would follow. (I don’t know out of hand how to achieve that with C4D though… you could use the joint skeleton for the clothes too through a second Skin object, but you’d need to weight the clothes.) With this method, you could roll up your polys in the sleeves as you are not doing real simulation, and art direct the behavior of the cloth with e.g. animated morphs.
(I wanted to write a plugin for this hybrid approach once, but never got around to it - maybe there is a method in C4D already.)

So… what kind of character do you want, for what purpose, in what quality, with what kind of clothes (jumpsuit or cape…), with or without cloth changes and reuse…?


#9

All good questions, of course.

In this case, it’s a rather cartoonish character that just needs to not look “wrong” in the sense of bad deformations, etc but it’s in a shiny music video with other cartoon elements, and I’ll likely use just stick with basic shading, fast renders, etc.

I need two characters. One already exists in high poly form (with some of the clothing edges rolled, and limbs disconnected from cloths). He is currently undergoing retopo for low poly animation workflow.

I still need another, though. He will also be similarly cartoonish. Smooth bends with no wrinkles is fine, though he will have a beard, top hat, and tails (Uncle Sam) rather than basic shirt / pants, and pre-made hair. Still not clear how I want to create him as I’m awaiting some answers about which (mac) creation software will give me the easiest animatable character with the least downstream workflow hassles. I’ve seen the high to low poly workflow (currently working through it.) I’d prefer not to have to do so much manual work on the second character (retopo, hand clothes fitting, etc) if there’s software that can just output a mixamo ready character for me.


#10

I am on a PC and don’t have Mixamo so I guess our workflows will not be too similar, but from what you describe, the tails and the beard are the only parts that work sufficiently independent. If this is as cartoony as I imagine, you may want to rig them with some extra joints and either automate the secondary movement, or even animate them on top of the figure for heightened comical effect. The rest would probably be good enough with clothes modeled into the character.