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kidult one
09-12-2006, 02:04 PM
I made a rig from the biped guide - but i would like legs i can move above the COG that dont flip around (do a 180) In my previous app u used something similar to a 2 point constraint to solve this. i.e. the leg up vector moves with the leg - letting u get it in all crazy positions.
any ideas or link for a tut on this? few rig tutorials mention this.

mattmos
09-12-2006, 02:31 PM
If I'm feeling lazy I place the upvector for the leg underneath the foot control so it moves with it, otherwise I just animate the upvector manually.

If you're getting leg flipping with the biped rig from guide are you using the roll divisions on the thigh? These were giving me flipping problems when I tried it...

kidult one
09-12-2006, 02:43 PM
wow that has to be one of the fastest replies ever! thanks will try (just deleted my rig and am starting another) it when i can - such a simple solution.
I was not using the thigh roll on the legs - just used to a more complex setup to get the no flip - sticking it under the controller sounds good to me though!

mattmos
09-12-2006, 03:01 PM
Quick note, for this to work you have to have the upv in front of the leg, if this reverses the way your leg should be then fix it in the roll parameters of the chain (in the thigh bone parameters).

kidult one
09-12-2006, 03:14 PM
thanx just tried it and it works perfect (also know now where to look for that pesky upvector ppg. Im amazed by xsi evryday the fact that i can change the up-vector so easyily a dream...

thanks matt:)

p.s. you work for studio aka? cos that stuff rocks awesome characters and animation!
just been animating for a year now (self taught) and cant wait to do stuff like that soon
(next month would be good ....):D

kidult one
09-12-2006, 04:49 PM
one more question - is an up vector nessecary on your leg bones? I got a better solution from changing the resolution plane to preffered axis - u can still use roll to dictate the knee direction and now the leg lifts up above the COG (kicking out in front or behind the character) - it seems an up vector limits? the chain movement - is it just for stability or am i going to suffer with no up-vector

Jesse-Irvin
09-12-2006, 06:48 PM
one more question - is an up vector nessecary on your leg bones? I got a better solution from changing the resolution plane to preffered axis - u can still use roll to dictate the knee direction and now the leg lifts up above the COG (kicking out in front or behind the character) - it seems an up vector limits? the chain movement - is it just for stability or am i going to suffer with no up-vector


Yeah I'm not a fan of up vectors either. Haven't had much in the way of problems with using the roll instead. I usually drop it in as a proxy param in a displayinfo set under the leg and foot control so I don't need to dig around for it when I animate. others link it to a curve parented to the rig.

kidult one
09-12-2006, 07:11 PM
I was thinking of doing a vector attached to a curve! i just tried the distance constraint but with in a few movements the vector moves to crazy - and a 2 point constraint is difficult to setup without making a cycle.
i really would like my vector to move with the leg in a fixed distance from root to tip no matter the position of the foot controller.
but other wise the curve idea is next - some tests without the vector had strange rotations not to bad but i like the more visual feed back of an up vector

Jesse-Irvin
09-12-2006, 07:23 PM
Whoa... now I'm confused... I thought you switched to using the roll?

kidult one
09-12-2006, 07:38 PM
Sorry been a long day...I've put the rig to rest for the moment and was just fiddling with a leg setup - the rig with just the roll is doing good but movement/rotation on certain poses is not hundred percent but might just be gimball lock (keep in mind noobie here)
the movement is really a bit unrealistic even for the cartoon rig - basically the leg starts of sticking straight out putting the foot nearly in line with the hip (a kick almost) and then the leg swings out to the side staying level until it goes behind him. So really never would i have such a movement but just wanted to try get a rig going with a vector. I dream of one day becoming a character rigger so its fun to play with all the differant setups!

mattmos
09-13-2006, 01:13 AM
thanx just tried it and it works perfect (also know now where to look for that pesky upvector ppg. Im amazed by xsi evryday the fact that i can change the up-vector so easyily a dream...

thanks matt:)

p.s. you work for studio aka? cos that stuff rocks awesome characters and animation!
just been animating for a year now (self taught) and cant wait to do stuff like that soon
(next month would be good ....):D

Yeah been here a little while now, there are some very talented folks here, its a great place to learn. What struck me though is actually how simple the approach is most times, rig as basic as possible to get stuff moving and then if there are any glaring issues it gets dealt with down the line (corrective shape here or there etc) but you fix what you can see rather than taking forever over a complex rig... basically there isn't one rig solution for everything, you just do whatever works for the shots its needed. Always good to know how stuff works though :)

Sbowling
09-13-2006, 03:54 AM
I dream of one day becoming a character rigger so its fun to play with all the differant setups!

If you are serious about character rigging, I highly recommend getting the entire Advanced character rigging set from 3dtutorial.com and going through it. After you have a good understanding of that I would then get the Rigging pro tutorials from 3dquakers.com. Both of these are excellent, but I think the ACR series gives a much better education on character rigging and should be first the first one you buy. The rigging pro shows how to make a very good and clean rig but it will be easier to understand what is going on after viewing the ACR series. BTW, the entire ACR series is about 27 hours of training. :eek:

kidult one
09-13-2006, 06:22 AM
Yup those training vid look good but the price...The exhange rate is not very good here where Im from so that series would take me awhile to afford (saving up for advanced xsi at the moment - its costs the same as buying a small family car )

Also in the previous software i was using the training vids i bought said the same things about rigs - specially that there is no one rig for it all and their's always seemed so complex.
Being able to get such stable rotations from a bone without vectors in xsi seems almost magic and the ability to change and add to the rig at any stage of production is awesome!

Today Im going to try some more ideas (hey at least i will be good at rigging legs after)

3dtutorial
09-13-2006, 11:23 AM
Yup those training vid look good but the price...The exhange rate is not very good here where Im from so that series would take me awhile to afford (saving up for advanced xsi at the moment - its costs the same as buying a small family car )

Hi,

I just saw your post and wanted to reply.

You might not be aware of this but I do offer a special bundle price on our ACR series.

The bundle price is US$129.97 and you get all 4 volumes in the series for that (27 hours of training).

I don't know if that helps you or not but I hope so.

Kind Regards,

/joe

kidult one
09-13-2006, 11:37 AM
Thanx that is a good special but the exhange rate of rand (our currency) to dollar is 7 to 1 so your package costs 900 rand (which is slightly more than alot of people here's monthly income) so.....
I do illustration and design (and i am trying to crack the animation world, got pretty good 2d skills just trying to get the 3d ones) and most of it is freelance so...hey as soon as I get that next big job i be 1st inline to buy:D

Getting of the topic a bit...Anyone now a good leg rig with up vector that follows at a constant distance so that it can kick above the waist infront and behind?

3dtutorial
09-13-2006, 11:49 AM
Thanx that is a good special but the exhange rate of rand (our currency) to dollar is 7 to 1 so your package costs 900 rand (which is slightly more than alot of people here's monthly income) so.....
I do illustration and design (and i am trying to crack the animation world, got pretty good 2d skills just trying to get the 3d ones) and most of it is freelance so...hey as soon as I get that next big job i be 1st inline to buy:D

Getting of the topic a bit...Anyone now a good leg rig with up vector that follows at a constant distance so that it can kick above the waist infront and behind?


Sure, I understand completely about the problems with the exchange rates, etc.

Kind Regards,

/joe

tredeger
09-13-2006, 07:00 PM
I'm not a fan of up vectors myself, BUT if you are going to use one, consider using it this way:

Once you've placed your up vector so that it controls the orientation of the knee, instead of controling it by moving it in translation, move it's pivot point away from the object center and snap it to the root of the upperleg bone. Set it's transform setup to be rotation instead of translation. Now when you manipulate the up vector through rotation, it will basically revolve around the central axis of the resolution plane at a constant distance. I find this more intuitive than figuring out translations that correspond to the roll I want. Also, a rotation curve is easier to read in the fcurve editor as it moves between 0 and 360 degrees with a sensible correspondence between value and effect.

kidult one
09-15-2006, 07:31 PM
Thanx tredeger - spent along time trying to do this with constraints/parenting

calmasacow
09-17-2006, 03:25 AM
I'm new to XSI but in maya it was called a pole vector constraint that pointed the knee. adn then we would take the locator "null in xsi" and the parent constrain it to the hip joint. this way it always stayed above the knee joint and resolved the flipping leg.

kidult one
09-17-2006, 09:03 AM
thanx but like I siad in the previuos post I tried all manners of contraints to duplicate this but in the end Tredeger's way was the fastest / most stable way - my contraints would only work up to a caertain point and the go way off after some crazy leg jiggling (really putting the rigs tnrough carzy over the top movements just to practice rigging solutions

in the end I found no up-vector better! the 2nd chains in xsi are super stable (well for me) and can think you only need them for 3d chains?

Then just a quick complete fanboy outburst - This program rocks for rigging, enveloping and animating. in 3 days i rigged and enveloped two basic bipeds (no muscle bones) with stretchy heads, chests and limbs with synoptic views and its my 1st time in xsi! (even got 1 jason osipa style face controller and expressions going!) the workflow is really intuitive and even with the really dumb mistakes i made - it was so easy to correct any part of it at any time!
I'm thinking of getting an xsi tattoo!:love:

mdee
09-18-2006, 08:51 PM
What I usually do is what Matt does (parenting up vector control object to the foot controller) but with a little twist, I don't parent it, but do some sort of constrain, so up vector control object only moves when you rotate foot control in Y. That way if you want to rotate foot towards the leg or bank it it does not destabilize the rig.

I am tired after work, so bare with me if it does not make sense ;)
I have attached the scene file, a quick look at schematic should explain everything. I find this setup pretty stable. As Matt said, KISS is good rule when it comes to rigging.

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