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madjester
01-27-2005, 06:37 PM
Okay I have a question...

How many people, speaking towards the more experieced members here, use weight maps for animation deformation?

Speaking from personal experience I cannot get weight maps to deform in a predictable mannor, being picky about how each poly is deformed I thought weight maps would be the perfect solution. I use tons of weight maps for texturing, which they work great for, but they seem to distort unpridictably for animation.

I have recently given up weight maps and found that the strength and limited range features work really well, though sometimes requiring one extra bone to get the best results.



For alittle referance on my question I am a college student, I taught myself LW back in high school and find it better than Maya, which I have classes in.
I'm worried that when I get into the 'biz' in a few years, my lack of skill with weight map animation may hurt me (Though I'm mostly a modeler anyhow).

ericsmith
01-27-2005, 07:21 PM
In the right circumstances, weightmaps can work very predictably. I tend to use them for things like fingers or elbows, where it's difficult to maintain volume without them. Then, on areas like shoulders, I use hold bones that help mimic real biology and skeletal structure.

The nice thing is that the situations where I use weight maps are also the situations where they are very easy to create.

Eric

WilliamVaughan
01-27-2005, 07:54 PM
I dont use them for fingers or elbows but I do use them to seperate the legs from each other. Also weight maps rock for surfacing, Sasquatch, and of course....dynamics! :)

SplineGod
01-27-2005, 09:41 PM
I tend to avoid them because its very easy to complicate a simple task with them.
Lightwave bones are different the the way bones in other apps generally work. Most other apps REQUIRE the use of weight maps to pin geometry to bones. Lightwaves bones are DEFORMERS already which means as soon as you activate them they work.

I tend to spread the fingers and other limbs a bit on characters so that I can avoid cross influence from bones. This is faster then monkeying with weight maps. Even when using simple weight maps you still have to make sure that EVERY vertex has a weight map (because no weight maps is not the same as a zero weightmap). You also have to make sure EVERY bone is assigned to a weight map. This tends to slow things down. In layout weight maps can also slow down a rig when checking deformations.

A more logical approach is to add the bones, rest them and then start testing deformations. This is a step you have to do anyways. I usually fixed unwanted or unexpected deformations by adding some hold bones which you can do very quickly in place. That usually works for me. In the end you arent prevented from using simple weight maps at this point but working more logically will definately keep things simple and save you time. :)

Rory_L
01-27-2005, 09:48 PM
Use Vertex Paint and start with a distance calculated set of Wt Mps. Then paint the weights with very low influence brushes (5% -ish) and check the deformation by rotating the skelegons right there in Vtx Pnt.

Then normalise your weights and in Layout make sure all active bones have Use Weight Maps Only turned on.

You will have to learn to use weight maps if you plan to have a career in the games industry. There`s no option!

Good luck!

R

ericsmith
01-28-2005, 12:23 AM
Even when using simple weight maps you still have to make sure that EVERY vertex has a weight map (because no weight maps is not the same as a zero weightmap). You also have to make sure EVERY bone is assigned to a weight map.

You've said this before, but I've never had to adhere to this rule. I've rigged numerous characters, ranging from simple to complex, and just put weight maps where they were needed. It's never been a problem.

Can you clarify what some of the negative side affects are supposed to be if you don't assign a weight map to every vertex, or if you don't assign every bone to a weight map?

Eric

NanoGator
01-28-2005, 12:52 PM
Even when using simple weight maps you still have to make sure that EVERY vertex has a weight map (because no weight maps is not the same as a zero weightmap).

Eh... You've got a point, but weight maps aren't nearly that bad. You can use a hybrid weight map/non weight map mesh without too much trouble. We do that all the time around here. We basically just have weight maps on the head, eyes, and fingers. They're great for isolating certain features (like the eyeballs) without having to do any sort of complex weight mapping. Really it's not much different than assigning a surface.

CB_3D
01-28-2005, 03:31 PM
You've said this before, but I've never had to adhere to this rule. I've rigged numerous characters, ranging from simple to complex, and just put weight maps where they were needed. It's never been a problem.

Can you clarify what some of the negative side affects are supposed to be if you don't assign a weight map to every vertex, or if you don't assign every bone to a weight map?

Eric

I think the main drawback is deformation speed.

madjester
01-28-2005, 04:29 PM
Thanks for all the replys, a great community for sure!

Humm two real problems, one using the "Weight Map Only" feature seems very all or none. For instance, I manged to get it working okay for a character but I had to use it for every bone and I had to make sure every vertex had 100% between the maps, no more or less.

Also trying to anticipate how the polys will bend at the pivot points of the bones is tricky. Sometimes they, the polys, would bend along a curve as expected while other times they seem to get pulled almost straight in one direction.

I had not explored Vertex Paint too much, thats a good idea. Also I have not explored weight maps on their own, I have always just tried to stick them into a rig without taking the time learn their details. Might be a good idea to set up a test scene just to fool around with'm without worring about other variables.

SplineGod
01-28-2005, 04:41 PM
Hey Bryan, Eric!
I usually make the eyes separate objects and parent them to the head bone. Ill create a bone in each eye that I target at something. Im not against weight maps its just that it generally is less steps when not using them. :)

Ive also used partial weight maps on setups. Sometimes it works and sometimes I start getting unwanted deformations that dont go away until I have at least two weight maps on an object. Sometimes if bones are not assigned to a weight map that same thing can happen. Random problems to me are worse then the non ramdom kind :)

madjester,
I would only use that option (weight map only) if you absolutely have to. Otherwise using it complicates a simple thing. If you use vertex paint I found it useful to cut/paste just the parts I wanted to weight map into another layer. This helps prevent 'overspray' when painting weights.

If you are going to use weight maps I HIGHLY recommened using FIs weightblur.
You select points and give them a weight value. Run the plugin and it will blur the values outward. The nice thing is that it will to the weight blurring along just the polys or vertices you have selected.
-Larry

pooby
01-28-2005, 04:43 PM
I would suggest starting with no weights but adding them where you need them to fix things.
Weight maps are a much more versatile solution than adding extra hold bones. (that is what we all used to do before they were introduced) as long as they overlap and blend out nicely there is normally a nice falloff effect.. If you make them suddenly go from 100% to 0% thats when you get odd deformations.
Fingers are best modelled in a natural position. I think it's bad to have to model your character in an unnatural pose, just to avoid using weights.. It makes no sense.
The best thing to do is to start off with a simple piece of geometry and add some bones and maps and experiment for an hour or so.. you'll soon get the idea of it all.
I would avoid 'use weight map only' It gets quite unpredicable and adds an element of confusion that you don't want.

Noratio
01-28-2005, 05:10 PM
One problem with weightmaps I had was that I decided to alter geometry in boots after weighting, no problem. But moved some points below 0 y-axis and they were dropped from bones influence, spent some hours worrying nothing seemed to help, moved points back positive y-axis and ok again.