How to correct improper rotation

[Leonardo Vega]

The problem lies within the up-vector of the bad leg. If I move it from behind the leg to the front of it... problem solved. If I delete it... problem solved. But no matter what I do (I deleted it and did a new one) I can not get the leg to bend correctly with the upvector positioned correctly in the back.

- Leo

[Leonardo Vega]

Ok problem solved!

I started to look at the manual and I noticed how you can "mute" envelopes and "deactivate" contraints, etc. So I deactivated all the constraints for that leg chain. Then checked it's rotation with the correct leg. I adjusted the rotations. Then started to activate all constraints and finally I activated the up-vector.

The cool part was "muting" the envelope! :D I can see the flexibility. I know I can save the envelope, so I will figure that out next.

Later!
Leo

[ThE_JacO]

there's no such thing as an "upvector correctly positioned on the back".

2D IK is a co-planar solver.
this means that to define a plane for the IK behaviour to be as throughly consistant as possible you need 3 points (a triangle is the perfect defininer of a plane).

this is your root, your effector and your upvectoring object.

however, once you solve the plane, the solution is still not unique, as you can have the same chain, with the same angles, living on the same plane, but oriented in two different ways.
to solve that the upvector is usually also used to lock the roll, how that will be locked though can depend from a number of factors.

easiest way out to negate the solution is to select the first bone, go in its kinematic joint properties and check the resolution plane tab. in there you can choose what solves the plane and add a roll of 180

[Leonardo Vega]

Thanks Jaco for that bit of wisdom...

I muted the envelope, picked the thigh bone, went to the kine/joints in property and under the resolution plane I did just like you said and the bones lined up :D

BUT... lol... when I unmute my character... his leg is twisted.

Did I miss a step?

- Leo

[Leonardo Vega]

Well the only solution I found was removing the envelope and assign a new one (I'm surprised "mute" or "deactivate" didn't work).

I guess next time I need to "check" the skeleton before enveloping... lol

- Leo

[ThE_JacO]

what I posted was meant to resolve your skeleton issue, not the weighting (which has got nothing wrong).

what you did was transforming a deformer, XSI reacted consequently.
all you needed to do to preserve your enveloping was getting the character in its default pose with this modification, select the bones and the effector you modified, and use reset actor, so that this modification you applied would have been its new default pose ( rest bone in LW if you're more familiar with it).

[Leonardo Vega]

Ah... so reset actor is pretty much just saying, "look use this rotation as the 'original' rotation and forget that any rotation actually took place" :) That way XSI does not see the leg as being rotated, but rather in it's default position.

Thanks Jaco! Any good tutorials or videos on proper workflow when rigging a character? Like a mini-guide that just mentions the steps we need to take (ex. draw bones, apply contraints, set default pose (?), envelope..etc).

But I must admit it's nice when you get into problems and you are forced to solve it. You learn a lot.

Question: I know you can set sliders to control poses, such as fingers being rotated. But I tried to use a implicit sphere's rotation to control the rotation of the fingers. I used "link with" and "set relative values", just like I did with sliders, but for some reason it doesn't work. Is this function meant to work only with sliders and not actual objects? Now, if I create a slider, link it with the rotation of the fingers, then link the implicit sphere with the slider, then rotation the sphere causes fingers to rotate. But just curious if I can "delete" the extra step of using a slider first.

Thanks in advance!
Leo

[ThE_JacO]

I'm not a big fan of rigging tutorials, as rigging (if you want to do it properly) is about knowing the basics of 3D, at least some basics of linear algebra and trig, and having a lot of patience.
there's no such thing as a set of steps to take written in stone, as every rigging challenge can be enormously different.

what you are after though is learning the tools and what they do, not really rigging as an art/craft, and for that going through the tutorials book and the manuals is going to teach you a lot.

once you are done with that you can move to rigging videos, and learn lots of bad habits from people who've never worked in a serious production their whole lives ;)

as for linking values, that will work with anything, but with sliders it can be somewhat simplified.
did you set the range of the link? because without setting at least 2 different values (and that's barely enough for a proper ranging operation) you won't see any progression in movement.

the manuals again would help enormously in these regards

edit:
I forgot to say that the above is, obviously, my personal opinion, and shouldn't therefore be taken too seriously by anybody, especially not by people with no skills whatsoever who record tons of overcomplicated rigging tutorials without having ever sent a frame to film or beta in their life :D

[Leonardo Vega]

I guess I was just after the things I should make sure I do before moving to other things like enveloping or animating. I'm trying to grasp the whole "reset actor" thing. But when I get home, I'll read up on it.

I set a range... like for example... when the sphere is rotated 90 degrees, the bones are not rotated, then when the sphere is rotated 180 degrees, the bones are rotated a certain amount. I did exactly as setting up a pose slider. But instead of using the slider, the sphere was the "slider" :)

But I guess there are more steps involved. Again, I'll look it up and check back.

Thanks for your help!
Leo

p.s. Some rigs are too complicated...

[Leonardo Vega]

Jaco: When I clicked on "reset actor" all my constraints became unoperational.

- Leo

[ThE_JacO]

I must have been on crack when I wrote the first reply.
reset actor is to move your deformer back to its reference pose.
what I should have said is "use set reference pose", hell knows what I smoked when I wrote that... (little manualling on your side would have made you find out though ;) )

anyway...

[Leonardo Vega]

Thanks Jaco :)

I don't have the manual, I have an online guide though. I go to it a lot.

I'm starting to get a "feel" for XSI, but it does seem overwhelming sometimes. I come from a Animation Master/Cinema 4D background. So I'm used to simple :)

- Leo

[ThE_JacO]

I could argue that XSI is just as simple as A:M is.
the difference is that XSI is more raw material and less interface help.
XSI tends to be incredibly easy and intuitive for those who grasp the concepts of a scene graph and the basics of 3D's under the hood mechanics, as it doesn't cover anything in fancy names and the tools are supposed to be few and versatile.

It can probably be a bit intimidating to those who just want to "get done with it" for a certain stage of the process, pretty much like the RenderTree, but if you focus on abstract and solid knowledge rather then button pushing, XSI nearly always makes sense, and your 3D cultural baggage will be more portable to other apps.

I've never had problems migrating my knowledge between Maya, Houdini and XSI, even when I only knew how to do something in only one of these packages, I could usually figure it out just as straightforward in the others if I needed, and then the app would make the difference only in terms of stability, elegance and performance.

I'm done babbling now.

[Just_David]

The problem lies within the up-vector of the bad leg. If I move it from behind the leg to the front of it... problem solved. If I delete it... problem solved. But no matter what I do (I deleted it and did a new one) I can not get the leg to bend correctly with the upvector positioned correctly in the back.

- Leo

would flipping the resolution plane of the upvector 180 degrees not solve your problem?

EEk just re-read Jacos post. he mentions this too. sorry.

[Leonardo Vega]

I definitely need to learn the "concepts" :) I don't know what the construction history even is or how to benefit from XSI's non-destructive workflow (up till now all my work and rigging has been pretty destructive lol :) ).

BTW, is the online guide the same as the manual?

My goal is to make a short cartoony film. I hope I will learn enough XSI to reach that goal.

- Leo

p.s. If I buy foundation now, will I get v5 free?

[ThE_JacO]

the html docs should mirror the manuals, infact since 4.2 a good chunk of the manuals is relegated to its digital form only, as the amount of pages was becoming too much.

as for the principles that rule on planet rigging, I'd suggest starting to study at least a little bit of geometry, trigonometry and linear algebra, the names of the disciplines are a lot scarier then the actual concepts, and most people shy away from the disciplines because the school days when these things made no sense are burnt in their brains.

The truth is that when you have such an immediate application of these principles as 3D is, the studying process is a lot easier and there's more immediate gratification to it.

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