Character model deformation question...

[Deleted User]

...Press your forearms together, one against the other. Press firmly. Your arms deform against one another.

If you're a woman and you're not wearing a bra currently, note how your breasts are being pulled downward by gravity and pressing against your ribcage. A bra cup lifts them up and away from your ribs but when you're braless, they will deform against your ribs. One part of your body (in this case, your breasts) change shape when bumping up against another part of your body.

When we humans are fat, our thighs rub together when we walk or press together (much like the forearm thing) when we stand. They deform against one another.

When I model, how do I get the model to physically do this? 3DS Max uses Reactor to simulate physical reality. Does the Reactor soft body collection account for how one part of a person's body can deform the shape of another part or parts?

If I, punchface, were a 3D model and I tried pressing my forearms together to get a look at the deformation, my arms would simply pass through one another. How can I get this to not happen to myself if my universe operates according to the physical laws of the almighty 3ds Max?

punchface

[Deleted User]

you must be level 74 magic to do that!

[Deleted User]

use the almighty flex modifier. im not quite sure how it works, cuz im not a big character man myself. BUT i can tell you it will work because flex is the modifier you use if you want biceps to bulge if you rotate the forarms and all that good stuff..

Oh... and it also helps if you have lvl 74 magic

Guerrilla

Not entirely sure soft body would be able to pull it off entirely (I'll work for breasts, but not sure about the other stuff), but it's worth a shot.

Or you could go the CG way of doing things and fake it. A couple of clever morphs should make a pretty convincing effect anywhere, plus you'd get to brag all your deformations are handmade.

[Deleted User]

Armorhead,

I always thought that flex made things wiggly and interactive with inertia only. For instance, if I applied flex to the trunk of an elephant model, it would then wiggle and dangle if I animated the elephant BUT, if, for some reason, this trunk bumped against the elephants leg, it would either bounce right off without deformation OR it would still pass inside of the leg for a frame or two of animation.

Guerilla,

Can you point me in the right direction to discover these "clever morphs" that you mention? Thank you sir.

punchface

IRML

it sounds like that flex thing wouldn't work, making biceps bulge with rotation is not the same as squashing 2 parts of the model together, in LW I'm pretty sure you'd add a collision effector to the model, and then apply some soft body dynamics

when guerilla says clever morphs he means you have to model the deformation youself and then keyframe a morph of that deformation to work when your arms come together, you can't just click a button and have it all done for you

Guerrilla

Well, technically you don't need to keyframe it. You can just wire it to, say, bone rotation. Essentially you'd have a torso in a natural state, and a bend over state (breasts move down, stomach 'rolls'... well... roll, if present, ribs move around). You model the changes, set up the morph targets and wire

them to, say spine bone rotation and you have a pretty automatic secondary animation when keyframing the actual character. Very nifty for simple muscle deformations, but I'm not sure about collisions.

I'd give soft bodies a shot as well, just out of curiosity. The deformations should be a no brainer, but you need to be careful not to have 'pudding man' in your hands. Skin and fat are soft, but bones and most muscles are hard, so you need something in there that maintains the shapes and keeps the model from being too wobbly.

[Deleted User]

For jiggle on body parts like breasts and beer guts I've found that the Spring position controller works well for a fast to set up and providing realtime feedback in your viewport (no messing about calculating Reactor solutions). It gives a reasonably convincing soft body-ish deform. It doesn't do self-intersection checks though, so you might get some crashing if you have your settings too "floppy".

The Skin modifier has a built in system for blending morphs that you should take a look at if you are using it.

I don't have enough experience with using Reactor on character models to really give you any ideas there. From what I've used it for it seems to apply the same softness throughout the model. Muscles would be just as soft as a pot belly unless theres some sort of tension modifier you can apply to certain areas. (I just noticed I'm repeating what Guerrilla has already pointed out!)

Setting up a character model to react realistically to any random pokes, flesh pressing together, and other deforming events you throw at it is quite a tall order though. It might be better to focus on a couple of effects to convey to the viewer the notion that the body is deforming properly, rather than go for the whole effect at once. I know that the pros will use several different rigs and swap them out depending on the requirements of what model is doing in the scene.

Good luck!