Riggin cloth banners/drapes - Maya

Michael

To whom it may concern,

Hello there! I have been working on an in game model currently, and have come across a slight issue that I would like to take up wtih everyone here. What I am trying to learn, is how to get a long flat polygon that's wide (resembling a cape or a bed sheet.) and make it flow. I am also wondering, once I do get it flowing, how do I rig the character to push the sheet away should it come in contact with her. The thing is, I had intended her character design to be simple, as she will be my first completed design. The problem is however that she has a drape which runs down her front from the waistline. Generally speaking, if I deform her legs, they cut right through it improperly, instead of pushing it away. I could of course paint it with weights, but the weights, as far as I know, would simply cause it to act as a skirt (Very stale.).

Any help would be most appreciated,
Doodle

Daz

Well, is this for in engine somwhere or is it to be rendered? You could use some much more elaborate solutions for the latter. Often the most common solution for in game is to add bones for the cloth and animate them by hand.

thomasp

yes, either animate it by hand or constrain your bones to a clothsim that's run on a higher res version of the cloth piece in question and bake down the transformations for export into your engine.

in some games, this clothsim thing is handled realtime, however the results are not perfect, especially if you have bodyparts really pushing against the cloth.

hawken

first step might be to break up that large polygon into lots of smaller polygons so the cloth sim can bend it

Michael

Alright, next question. I've been researching it, and have found that I might wish to use Forward Kinematics? The problem is, I am trying to found out how I can break the names of the joints down into a heirarchy, so that I don't need to name each one individually. Then, I would assume that I would need to know their obvious percentage to paint the weights properly, as far as the drape goes.

Btw - Daz - Clothsim? Are we talking the $7,000 version of Maya? xD;

Scott Ruggels

There is an answer for this in Maya, but you need a copy of Maya unlimited 7 and you can use the hair o drive a spline, to drive the bones in a skeleton and then "bake out the smulation". The details are in 3D World Magazine Issue 75 (the one with the naked blonde onthe cover. This works for engines that can hand;e only bones. I will be using a version of this for the loincloths and other attatchments for my lupine models for Unreal2K4.

Scott

pyromania

Hair curves and a cloth sim would give you the best result but if you don't have unlimited, you can still rig something up with active/passive rigid bodies.

Create a bunch of poly cubes and make them active rigid bodies. Point constrain joints from the sheet skeleton to these cubes. Then create spring constraints between your active rigid bodies, so that the joints don't warp out of shape. The character's geometry can then collide with the cubes, which then drives the joints in the sheet. Once the simulation works the way you want, bake all the animation down to the joints.

Shawner

Keep in mind if you're doing simulations you'll probably have to bake out the simulation then edit your keys to make the animation seamless.(If you want to use the animation in cycles)