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bobzilla
10-08-2006, 09:59 PM
I know this is a big subject with lots of options, but I just have one question (for now).

How can I use contraints, weather C4D's or Dan's (they seem similar) to act like the Constrain Goal in the IK tag? I can't seem to replicate it no matter what I do.

It seems in other apps (I may be wrong) like Motionbuilder, Maya, XSI, when I see someone animate the character the goals don't move from the end the chain. Especially on hands and feet.

Or, maybe it's just a personal preference.

Thanks...
MJV
10-08-2006, 10:34 PM
In the advanced tab of the IK tag there is an option to constrain goal.

Opps, rereading your question I guess you already knew that.
LucentDreams
10-08-2006, 11:43 PM
use a clamp constraint.
bobzilla
10-09-2006, 12:04 AM
I tried that, but then the Goal doesn't move at all. I must be doing something wrong.
LucentDreams
10-09-2006, 01:20 AM
is it set to fixed? theres optiosn for min and max as well. Min means the object can move anywhere you want as long as it doesn't get closer than the minimum, max lets it move around as mucha s it wants as long as it doesn't exceed the maximum.
bobzilla
10-09-2006, 01:40 AM
I tried a bunch of options, but none of the seem to work the way I want: to keep the goal in place.
bobzilla
10-09-2006, 01:46 AM
Parent Constraint almodt works, but the hand bone stretches than.

I'm using the turtle arm, BTW.
flyingP
10-09-2006, 09:30 AM
How can I use contraints, weather C4D's or Dan's (they seem similar) to act like the Constrain Goal in the IK tag? I can't seem to replicate it no matter what I do.

couldn't you do that with Dan's distance constraint ?
LucentDreams
10-09-2006, 10:26 AM
maybe its your logic. What are you constraint from and to?, whats your expression priorities.

Constraint the goal with a max clamp, to the root, using the overall length of the chain (or include a longer length to allow for stretch.
bobzilla
10-09-2006, 11:58 AM
OK. Changed Priority to 1 and now it works.

Yes, Dan's would work too...if I used it correctly!!

I really need to understand priorities...a little confusing right now.

Thanks for the help...
LucentDreams
10-09-2006, 08:56 PM
The first video in my constraint series on cineveristy will be priorities. This should apply to Dans constraints as mcuha s cinema's really, heack even applies to setting up constraints manaually in xpresso.

Priorities are essential when dealing with relationship expressions and the hardest part is knowing when certain things like cloth and IK calculate within this priority list
bobzilla
10-09-2006, 08:59 PM
Looks like I'm going to have to pony up for Cineversity!

Sounds good...
Cactus Dan
10-10-2006, 04:25 AM
Howdy,
I really need to understand priorities...a little confusing right now.
Yes, this is very important for rigging, but it's really not all that difficult to understand. A good rule of thumb is: always try to constrain an object to one that's above it in the OM, but if that's impossible, then up the expression priorty on the constraint. ;)

Adios,
Cactus Dan
LucentDreams
10-10-2006, 10:45 AM
Howdy,

Yes, this is very important for rigging, but it's really not all that difficult to understand. A good rule of thumb is: always try to constrain an object to one that's above it in the OM, but if that's impossible, then up the expression priorty on the constraint. ;)

Adios,
Cactus Dan

thats a good rule of thum, just a note too that Tags have a hierarchy (easy to see in vertical layout) In the standard layout the hierarchy is left to right so if a constraint is to the right of say IK, it should solve after the IK, if its to the left of the IK it is solving before, so when considering if somting is above or below in Dans rule consider this tags hierarchy as well.



Clamp constraint, becomes far more complex because of its ability to look at generator and deformed surface and points, and anything using cloth or IK/FK blending as the IK solves at two points in the priorities, as does cloth. Spline Dynamics has a crazy default priority to make it always come last, and the hair object has its own priority which is important for whether its generating geometry or just hair etc.
bobzilla
10-10-2006, 11:47 AM
That's good. That's what I need. Some rules to follow. That will at least get me started.

And that is exactly whay I had to change the priority. I was contraining to an object below (in this case) and it only worked properly when I changed the priority.

Thanks. Starting to make some sense...
AkaKico
10-10-2006, 02:36 PM
Anybody figured out the exact procedure for sticking a button to cloth? I got it to sorta work... but it drifts and the orientation isn't quite right. At this point all I know is "Use Clamp" *scratches head*

Chris
LucentDreams
10-10-2006, 04:12 PM
no one plays with settings?

set it to fix so it doesn't slide, Surface so its on the surface of the cloth, and align to normal.

should work quite well, it its still popping a bit, try setting the priority to generators 150
AkaKico
10-10-2006, 04:41 PM
I tried different combinations of all the options of the constraints, suppose I was missing something :( I'd normally play then read the manual then play again. But it's not up yet... Thanks anyway Kai...
LucentDreams
10-10-2006, 05:10 PM
I tried different combinations of all the options of the constraints, suppose I was missing something :( I'd normally play then read the manual then play again. But it's not up yet... Thanks anyway Kai...

Lemme know if those settings work for you. Sorry if I came off snippy, i know you guys don't have manuals, jsut its also hard knowing most of this will be covered in very specific tutorials already, that also aren't available yet, and not coming off as a salesman allt he time is difficult too.
AkaKico
10-10-2006, 06:21 PM
It's okay Kai. I appreciate all the help you give to the forum :). So far I got a small cube to stick to the cloth which is pinned at two corners. It don't seem to be slipping so that's good. I'm having trouble figuring out how to keep it aligned to the face of the cloth though. I did a work around where it targets two nulls that I also stuck to the cloth. But I imagine there is a better way. Get some very odd results with certain settings. Seems very powerful tho, lot's I haven't gotten too yet.
LucentDreams
10-10-2006, 07:57 PM
setting the AS to normal doesnt' help the alignment?
AkaKico
10-10-2006, 08:04 PM
Well I've changed so many settings now I should probably start over. I was set to "point" for To. On "point" normal was freaking out. But I just swapped it to Surface and now it seems to be working perfectly. Perhaps I forgot to set "lock position" the first time. I'll figure it all out soon enough. Thanks a bunch Kai!
AkaKico
10-10-2006, 08:15 PM
Dont' know what I was doing wrong before because it's working like a charm now. Clamp works absolutely fantastically. Spring is awesome too! There goes 80% of my need for expresso :D

I see why you were frustrated Kai, it's like two clicks and works perfect. No manual needed :) I blame user stupidness for this one^^
LucentDreams
10-10-2006, 08:48 PM
that is the one problem with the clamp constraint, so many options that playing around can often make it hard to go back to what worked etc.
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