PDA

View Full Version : Xpresso and rig building


backlashcs
10-27-2005, 09:09 PM
Can anyone point me in the right direction to learning xpresso for rigging? Rigs contain express but there hard to figure out. I know about the global rotation and global position and such like that, but I am not really sure on how combine them in order to get a good rig. I am useing cd ik tools if that helps you. But I am just scratch your brains and hopeing to get some help with xpresso and rigging. I know how to set up the bones and such in CD IK but I don;t know how to set up good constraints so that my rigs will be working right. I know others are looking for this info too, so maybe if we can start a tips guide or such of useful xpresso set ups for others to add to there rigs that would be great.

Cactus Dan
10-28-2005, 03:49 AM
Howdy,

Well, when setting up constraints in Xpresso there are two important tips to remember: Exectution order and Priority. The execution order in the OM is top-down for objects and left-right for tags. If you're constraining an object high up in the list to one that's low down in the list, then it's trying to constrain to an object that hasn't been positioned yet. So, you'll get a delay or lag in the constraint. You can change the Xpresso tag's prority setting to a higher number so that its execution will be moved up in the prority list, or if it's possible, you can move the target object up above the constrained object in the OM. Which method you use depends on how your hierarchy has to be set up.

When it comes to rigging, you need to keep this in mind and set up your hierarchy to get the best performance from your constraints.

Adios,
Cactus Dan

LucentDreams
10-28-2005, 05:02 AM
When it comes to rigging, you need to keep this in mind and set up your hierarchy to get the best performance from your constraints.

Adios,
Cactus Dan

Yea most xpresso you see on rigs right now is likely to be some sort of constraint as Dan said. Fortunatley there are two plugins that iwll cover msot of this for you, either Dan's constrain plugin, or Third Party's CAR tags plugin which has a constrainer tag. both systems can do most constraints quickly and easily and perform better then xpresso variations.

The Key thing with constraints is more in how you set up your hierarchies of both your skeletons and your controller, the constraint is typically going to serve one of two purposes, either ton connect seperate hiararchies together, or to a connection between a controller object and a bone there are a few other uses but most will be one of those two.

crackle
10-28-2005, 06:17 AM
you can take a look at this rig i made with CD's Iktools. it may give u some kind of idea of what kinds of expresso to use and where to use it. this thing is Not perfect by any means. just think of it as a learning tool to grow from

http://webpages.charter.net/deolsons/GENcdik.c4d

Stray
10-28-2005, 07:52 AM
Hey Guys,
I thought I would pipe in too. Although my rig doesnt use CDIKTools it does use a bit of expresso. What I set out to accomplish with my rigging tutorials was a basic rig that would complement any other toolset available.

In my experience to get a decent rig going you need (at least) an up vector function of some sort, a global rotation function, a target function and some sort of IK constraint system.

Putting those peices together into more functional hierarchies like spines , rotate plane solvers for arms and legs and global rotations for things like hands and feet can take a bit of experimentation. I think that it can be argued that more than a few examples of each are available.

Dan touched on something pretty important in that calculation order is something to be aware of. You may have all the right tags on the right objects but in the wrong order in the OM. Also thing slike spines can be problematic becasue their hierarchies can run pretty deep and their calculation order may have to be setup to work from th edeepest most object to be calculated first.

I dont know how well my rig plays with CDIKTools although I think that some CA functions should be fairly universal.

hope any of this helps
-Danny

backlashcs
10-28-2005, 01:37 PM
Those are some good tips, can anyone point me in the right direction on seting up a good right with xpresso? I will check out your rigs you posted. Also has anyone done that mocca rig tutorial and tried it with cdik tools becasue I know they use xpresso, but can that same expresso be applied to other rigs with CD IK tools?

LucentDreams
10-28-2005, 03:32 PM
Hey Guys,
In my experience to get a decent rig going you need (at least) an up vector function of some sort, a global rotation function, a target function and some sort of IK constraint system.
-Danny

good list, and believe it or not everyone of those can be done entirely with xpresso, and
Chap here on cgtlak that I worked with on an HP commercial last month, actually managed to get an IK solution of sorts entirelyw ith xpresso no CDIK or MOCCA at all, and fairly stable though lack the upvectors but there are already a few xpresso upvector solutions out there.

Cactus Dan
10-28-2005, 04:04 PM
Howdy,
Also has anyone done that mocca rig tutorial and tried it with cdik tools becasue I know they use xpresso, but can that same expresso be applied to other rigs with CD IK tools?
Yes, CD IK Tools is a set of Expression tags, so you can mix any other expressions with a rig built with CD IK Tools. The only thing to watch out for is that you don't try to have more than one expression trying to do the same thing to an object, so that they are fighting each other for control of the object. That goes with any expressions, whether they are two Xpresso tags fighting each other or an Xpresso tag fighting with a plugin expression tag.

The only real difference between an Xpresso expression tag and a compiled C++ expression tag is the execution speed, and of course the other functions that C++ has more access to in Cinema 4D.

Adios,
Cactus Dan

backlashcs
10-28-2005, 08:48 PM
so therefor is xpresso really needed? or can I still build a stable good rig with only useing cdik?

slouchcorp
10-28-2005, 08:57 PM
i use mocca with cdik tools for all my rigs. but yes to answer your question you can build any rig you want from cdiktools without xpresso,however if you need constraints you will have to use any of the 3 methods, id recommend one of the plugin ones as xpresso tends to slow down some.


Mike

Cactus Dan
10-28-2005, 09:15 PM
Howdy,
so therefor is xpresso really needed? or can I still build a stable good rig with only useing cdik?
Well, these days, I use my CD Constraints plugin when I need constraints, but I use Xpresso a lot for when I add User Data controllers to my rigs. CD IK Tools will give you a stable rig to begin with, but to add custom controller setups you need to add User Data controllers and tie them in with the rig through Xpresso.

Adios,
Cactus Dan

backlashcs
10-29-2005, 05:25 AM
what do you mean when you say "user data controlers"? are you talking about the feature to add sliders and such to the hud?

backlashcs
11-01-2005, 10:54 AM
bump anymore advice on things I can read up on to get myself started in xpresso for rigs?

Cactus Dan
11-01-2005, 01:26 PM
Howdy,

Hey, this thread got moved. :eek:

Well, the two best sources for Xpresso techniques are Maxon's web site and Srek's web site: http://www.bonkers.de/

It's difficult to say "you need this Xpresso" or "you need that Xpresso" for a rig, because every rig is a bit different. For example, the elephant rig that I did is using an Xpresso setup similar to the "Follow the Leader" tutorial on Maxon's web site to set up the ears so that their movement lags a bit.
http://www.cactus3d.com/ElephantRig.mov

Adios,
Cactus Dan

LucentDreams
11-01-2005, 02:37 PM
you can build an animatable stable rig without any xpresso (well I might bite my tongue a little and say with CDIK you should be able to, mocca won't be totally stable without a little)

Thing is you'll be left with awkward aniamtion hierarchies andlimited controls. The idea behind using xpresso si tosimply things for the end user, the animator. A riggers job is not just to make a character movable, but make it as easy as possible to work with and perform as fast as possible. This is where rigging becomes more of an art then most people like to treat it.

Cactus Dan
11-01-2005, 03:07 PM
Howdy,
A riggers job is not just to make a character movable, but make it as easy as possible to work with and perform as fast as possible.
This is exactly what rigging is all about. ;)
The fewer controllers the animator has to animate to get the character to behave, the easier the animator's job is.

Adios,
Cactus Dan

backlashcs
11-01-2005, 08:38 PM
Do you still suggest to use vertex eight maps along with CDIK? I would asume so but I am just double checking.

Cactus Dan
11-01-2005, 09:14 PM
Howdy,

Vertex Maps or Claude Bonet. They're both not too different. Just in how you set them up. I use Weightlifter pro, which handles both.

Adios,
Cactus Dan

backlashcs
11-02-2005, 02:47 AM
kainor (http://forums.cgsociety.org/member.php?u=88846) vbmenu_register("postmenu_2775112", true); I looked at your rig, and that's really awsome. I can see everything and it's easy to animate. I think I am getting there I am seetting up my spine and legs and neck so far. What is so complicated about your rig is the fact you worked posemixer in with it.That is just awsome how you set up the userdata. Am I right when I say it is all run from the bones and not the poses?
The facial controls with that rig are just insane, you must have learned alot from seting up a rig like that.
Second question, what is CD Spinal and is it just like spinal IK?

Cactus Dan
11-02-2005, 12:55 PM
Howdy
Second question, what is CD Spinal and is it just like spinal IK?
CD Spinal works like the "Isner Spine" in XSI and is specifically designed for rigging backbones.

Adios,
Cactus Dan

crackle
11-02-2005, 06:03 PM
kainor (http://forums.cgsociety.org/member.php?u=88846) vbmenu_register("postmenu_2775112", true); I looked at your rig, and that's really awsome. I can see everything and it's easy to animate. I think I am getting there I am seetting up my spine and legs and neck so far. What is so complicated about your rig is the fact you worked posemixer in with it.That is just awsome how you set up the userdata. Am I right when I say it is all run from the bones and not the poses?
The facial controls with that rig are just insane, you must have learned alot from seting up a rig like that.
Second question, what is CD Spinal and is it just like spinal IK?

i believe CD answered your question on CD spinal.

thanks for the comment. Posemixer is really easy to set up now in V9+, it can be put anywhere in the hierachy to fit your needs. the facial controls are mostly bones, i had read some maya tuts on facial rigging and wanted to give that method a try.

i would have rather used CD's Morph but i thought not to many people had it and wanted everyone to be able to use it.

the hardest part about the sliders(and you can look at the xpresso) was figuring out wether to use global coordinates or not. you'll see when you look at it.

i think the most frustating thing about all this has been all this time i have spent rigging a character the way "I" want it and haven't much time to animate it. i want to be an animator not a character rigging artist......

backlashcs
11-02-2005, 07:37 PM
Yes I agree, but also the fact of rigging your own character is that you know what each character can do. Also does it help when you have the head and ebrows and eyelids seperate geometry to make the bones work? Or can I add the bones to my geometry if they are allready part of the main character? Also how does cdspinal differen from the spinal ik?

crackle
11-02-2005, 08:42 PM
the eyebrows were an afterthought, and the reason i left the head seperate was because i thought it would be easier to do morphs with plus keeps the filesize down. and because i had already made the head morphs, to add the eyebrows to the head i would have had to redo the morphs.

cd spinal has 2 controllers, base and tip. thats it. you can not add more goals/targets to that expression.

there is NO spinal IK in mocca, other apps have something simular though.

CD's spline IK, which could be used for a spine, can have multiple controllers/targets.

does that answer your Q?

also if you have CD's ik tools, there are examples in that plugins folder. IKBOBNEW.c4d is quite a study.....

backlashcs
11-03-2005, 10:11 AM
Has anyone ever gone through any of cd's rigs and tried to explain what the expresso does in them? Also how can I add new xpresso properties under the object menu.

Second question:I know in xpresso when you click the object say the red box on one I only get around 4 options for the object, but when I looked at cd ik bob he has around 6 or 7 other expresions that I could use. How do I get these am I missing somthing?

backlashcs
11-04-2005, 12:48 AM
bump, I am really wondering about the second question.

LucentDreams
11-04-2005, 01:11 AM
sounds like he has added custom users data tothe obejct in the attributes manager

crackle
11-04-2005, 05:11 AM
you dont "get" the other expressions, you make them yourself. all the expressions in xpresso are "hand-made".

CD is working on a tut for his plugs. the best thing you can do really is to break it down into Leg, spine, arm, neck/head and figure out how he did it... that's what i have done and am still doing.

try this, open newikbob, delete all the parts of ik bob ( look for a {p} in the name of the object and delete it. after all that you should have what i call ikbobnaked. then study it and off to the side try to recreate the same leg set-up, spine, and so forth. pay attention to his hierarchy and naming scheme, and compare it to his expresso and you should see the light.

backlashcs
11-04-2005, 10:04 AM
where can I create this user data? Sorry for seeming "newbeish" I have just not been able to get around to messin within cinema for a while so I am just asking others how they have accomplished things, then gathering it all together and having a go at it when I get the chance.

crackle
11-04-2005, 04:08 PM
ok, even if you dont have mocca, have a look at this tut.

http://www.slouchcorp.com/mocca/m2101.htm

it goes over building a rig with mocca. but, it also touches on making user data sliders AND xpresso for rigs. it's basic but is should answer alot of your questions as well as give you a basic understanding of user data sliders and xpresso.

ok

backlashcs
11-04-2005, 09:04 PM
I have done that tutorial, but I can't remember it adding use data sliders except for the fingers to set up a roll controler. Did I miss somthing?

crackle
11-04-2005, 09:08 PM
same thing

backlashcs
11-04-2005, 10:57 PM
Did you driver keys for your custom data. When I looked at your rig you didn't seem to have the expresso tags that go along with the drive absolute keys.

crackle
11-04-2005, 11:12 PM
not in the cd iktools version but in the mocca version i did. either way, you set up sliders in the same way. you create the user data slider in the attributes manager for the object, then link it up to what you want to control in expresso.

so in the mocca tut he links the slider to the p rotation of the driver bone

in my face rig i linked the slider for lower jaw U/D to the position z of the lower jaw bone.

same principle, different objects.

actually i did the same thing as the fingers, set driven keys, for the toungue curler slider. take a look.

backlashcs
11-04-2005, 11:15 PM
Wow I get it, dang I am stupid ahahaha I read over the moca tutorial and then applied it without data keys and got it, well somthing like that useing the mininum and max values set for the movement. But with the facial stuff do I need any null bones and such like all my limbs?

crackle
11-05-2005, 01:07 AM
no, but for fun try it both way and see what you get

CGTalk Moderation
11-05-2005, 01:07 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.