Skinning.. turn of deformation or lock dimensions possible?

[dragorago]

Hi..

 

I'm working on a Oblivion armor model.. atm im doing some skinning at Gmax/3D Max but dont have that much experience with it.

So far all is working fine except one thing: For example I wanted to make a couter (armor on elbow) which moves with the upper- and underarm (like 50/50).. so if I move/bend the underarm the couter shall also move around the elbow but not with the same strength as the underarm moves/bend.

So I used the normal skinning.. added the upperarm- and underarm-bones (also tried the twist-bones there) and tried different weight-sharings between those 2 bones. It works but only up to a certain point when the underarm moves/bends too much the couter-model starts to deform/scale-down. (I have also similiar problem with the shoulderpad..)

 

 

So the question is: Is there any way to lock the dimensions/deformation/scaling of a object when using skinning (so the object only moves/rotates)? (already tried a lot but nothing really worked so far)

Or is there maybe another/better way to do what I wanted to.. maybe with links?

[baduk]

Hi!

 

I dont know much about rigging with oblivion skeleton, but I guess you can just ignore that scaling stuff.

I have seen what you are talking about. the geometry scales down when bones theyr rigged to are bent at very acute angle.

 

But during normal and natural animations its not going to bend that far and i think the constraints on the skeleton will prevent it from bending so far on ragdolls also.

[LHammonds]

I have no idea about that but I do know the skeletons used in Oblivion are very problematic around the shoulders. I use Blender and the best workaround I've found is to make sure you use good model design to allow extreme bending in those areas.

 

I saw a tutorial once that helped me out quite a bit...I'll find a link and maybe it'll help you out with this as well.

 

EDIT: Here it is: Articulation by the seat of your pants

 

LHammonds

[Ghogiel]

I have done several couters. they just take some careful rigging. what you are describing is unavoidable in some circumstances. Areas with blended bone weighted that is further from a bone joint will bend differently in context to something close to the bone. the only solution is having it weighted to a single bone. Ideally it's own bone. Or never bending the elbow. Since none of those are viable- you are either fighting clipping or avoiding unwanted deformation. Happy rigging :thumbsup:

 

rigging involves some compromise. The best advice I ever got was, generally speaking a developer will always favor deformation over clipping as the lesser of 2 evils. And thats the only rule I have with rigging.

 

 

While most of the bones are self explanatory from their names, and at a glance you can see what they do, the twist bones might not be immediately apparent.

Arm twist bones aren't for controlling the elbow, the upper twist is for shoulder rotation, the lower twist is for hand rotation < the movement you do that would turn your hand palm up to palm down. I wouldn't rig couters to them, especially not forearm twist. At least not instinctively.

Edited January 3, 2011 by Ghogiel

[dragorago]

thnx so far for the replies

 

@baduk:

well.. (in oblivion) for example when the char is walking/standing the arm only bends a little.. but when holding a 2handed-weapon the arm bends over 90°.. in this case you can see the scaling-down a lot ;-) (but i think i can make it work with a lot trying)

 

 

@LHammonds:

yaeh.. the shoulders are another big thing :D i think at least its also up to bringing the bones to a good "average" position and then add this bones to the armor part.. think so i can make such special parts work. but of course you cant make the 100% perfect rigging/animation.. for example when you have a hugh plate armor and then you apply the bow-attack-animation.. ;)

(and thnx for the link)

 

 

@Ghogiel:

agreed.. the rigging can be a lot of "fun".. especially when youre doing it the first time ;-)

im working with some single armor-parts and of course it would be better to have one full model.. but well as i said above i think i can make it work with some bone-positioning before rigging.. and of course as you said i have to compromise not getting all to work perfect. ps: i just mentioned the twist-bones cause i tried a lot with different bones ;-)

think i can handle the couters in that way: first bending the arm-bones to ~45°.. rotate the couter to something like 45° too and bring them to the right position at the ellbow.. than adding the upperarm/forearm to the couter and do some testing with the weights. so the arm bends at least only like 45° (to each side) which prevents some of the down-scaling (compared to the 90° bending)

 

 

 

ps: also some strange section: the neck/throat-area.. at normal standing/walking all is working normally.. but at the 2handed-animations the head is twisted to the left and also the upper-body bends a little down/back so you get a long throat.. which looks a little weird.

but it seems its a "normal" thing at oblivion-models ;)

Edited January 3, 2011 by dragorago

[dragorago]

I have no idea about that but I do know the skeletons used in Oblivion are very problematic around the shoulders..

LHammonds

 

 

ah well youre right XD

i underestimate the shoulder-section a little.. i planed to use some bigger static pauldron-armor.. and it works pretty good at normal idle positions.. but at a lot animations where the arms do a lot of work i get some clippings with the pauldron. sadly there not much bone-choices there.. the shoulder-helper is similar to the clavicle.. and i also cant really add the pauldron to the arm-bones cause it would bends/twists the pauldron (a lot)

 

so either i will do a pauldron redesign or i will keep the more static pauldron (bound to a clavicle-bone) and just live with the clipping.. *happy rigging* ;)