multiple parents

Animation tools, character animation, non linear animation

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Money_YaY!
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Joined: Wed Oct 23, 2002 2:47 pm

multiple parents

Postby Money_YaY! » Sat Dec 06, 2003 2:46 pm

What happened to this feature ? It was being thought out and developed
it would help the rigging a great deal. To make some nice dynamic rigs.

I was trying some stuff
http://aprilcolo.com/oh/plink/tab.blend
http://www.aprilcolo.com/oh/natch/simpl ... ts/dog.zip
http://aprilcolo.com/oh/plink/plink.html

but something is just not right....

I think I need multiple parents to do what I was thinking. As I see it the world works like this:

two loose chains conected to an apple in the center . If one side of the chain say the left is pulled it will first take up it's slack then it will begin to pull the apple and the right chain. Same goes for the other side.
Their for the apple has two parents.

In Blender. same scene. But Only one chain can pull while the other has no power.

If I do a Copy LOC constraint for the apple if will get pulled right away with any chain being pulled no matter the slack. BUT ! their is a bug that prevents the apple from having two copy locs and behaving right.

What can I do ?

Will multiple parents ever come about ?

matt_e
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Postby matt_e » Sun Dec 07, 2003 3:42 am

I'm not exactly sure what's going on - it would help if you are more descriptive with your scene. But one thing I can see is that the centre 'Bone' is the parent of your arm bone, but is also copying the location of the arm bone. I have a feeling this would cause problems, because it is making a loop. 'Bone' copies the arm's location, which gets it's location from it's parent, 'Bone', which copies the arm's location, etc. etc. etc.

Try and find a way where it's split up further, so you don't have bones getting their co-ordinates from their children, and see if that makes any difference.

Money_YaY!
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Postby Money_YaY! » Mon Dec 08, 2003 4:09 pm

hmm. true .

What I was thinking.

If the centre 'bone' was parent off all bone chains. Then when pulled it makes rig shake all abouts.
So if it then followed the arms the arms could have the same effect and have the body shake all about with out having to select the centre 'bone'

I have tested other rigs and can make it some what do this but it still stalls. I wish for more help and insight if you can help.

The html site shows an example of what I want to happen.
Grab and pull only one hand and when it is pulled to far it will pull the entire body.

From all of this testing I have come to the conclusion that just like facial animation and the many faces that need to be made for emotion, their should be several rigs for one model. So one could be a walking and a dancing and a fighting bulgeing.

BUt whatever, it is all fun , but their still needs to be a speed increase. Ugh me head go poop from the slugy nature of the poseing ^v^ :D

Money_YaY!
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Postby Money_YaY! » Mon Dec 08, 2003 4:25 pm

I posted above to but the board is not showing that I had posted so I hope that you see that one.

Have you played with www.kaydara.com yet ? free demo. open the TRex demo that shows pretty much what I was hoping to do .... for this round of thoughts...

Money_YaY!
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Postby Money_YaY! » Tue Dec 09, 2003 1:55 am

New one. Please somebody help in anyway.

http://aprilcolo.com/oh/plink/crawl.zip

It is just Ik parented to the belly. One hand will pull while the other will not . Is this a bug ?

theeth
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Postby theeth » Tue Dec 09, 2003 3:00 am

Not a bug AT ALL, and this should give you a good hint at why this happens.

Image

Martin
Life is what happens to you when you're busy making other plans.
- John Lennon

Money_YaY!
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Postby Money_YaY! » Tue Dec 09, 2003 1:49 pm

But if you press the IK button the other side will depress it'self

theeth
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Postby theeth » Tue Dec 09, 2003 3:14 pm

IK Solving: Finding the best solution for a chain of vectors (bones) to reach a position in space from a starting position.

Now, try to stick the concept of a bone that is part of two different IK chains in there and see if it fit.

And you don't want that for your rig anyway, because move the arm within the limit of its range would rotate the torso in weird angle because it includes it in the IK solution.

What you'd need in this case is something like a location limit constraint where you'd set a small bone in the middle of the shoulder blades, parent it to the torso and set this constraint with the arm length as a limit pointing to both IK solvers. Such a constraint would probably be very easy to code.

Martin
Life is what happens to you when you're busy making other plans.

- John Lennon

Money_YaY!
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Postby Money_YaY! » Tue Dec 09, 2003 3:35 pm

theeth wrote:IK Solving: Finding the best solution for a chain of vectors (bones) to reach a position in space from a starting position.

Now, try to stick the concept of a bone that is part of two different IK chains in there and see if it fit.

And you don't want that for your rig anyway, because move the arm within the limit of its range would rotate the torso in weird angle because it includes it in the IK solution.

What you'd need in this case is something like a location limit constraint where you'd set a small bone in the middle of the shoulder blades, parent it to the torso and set this constraint with the arm length as a limit pointing to both IK solvers. Such a constraint would probably be very easy to code.

Martin


Oh mighty Theeth could you code such a constraint ? Please. The blender world be be ever so grateful if you were to give use the power of "location limit constraint" . You have surmised what I was attempting to do and it seems that you now see the road block that I can not pass without it.

:D

theeth
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Postby theeth » Tue Dec 09, 2003 3:54 pm

Working on something else now and I have other plans for 2.32. Will see if I can squeeze it in.

Martin
Life is what happens to you when you're busy making other plans.

- John Lennon

Money_YaY!
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Joined: Wed Oct 23, 2002 2:47 pm

Postby Money_YaY! » Tue Dec 09, 2003 8:02 pm

theeth wrote:Working on something else now and I have other plans for 2.32. Will see if I can squeeze it in.

Martin


Well at least there is hope. Can you recommend me to ask somebody else that might have a bit of free time for it ? That would relieve a little pressure for you.

thankyou :D

theeth
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Postby theeth » Wed Dec 10, 2003 12:19 am

I posted some time ago a coding guide on how to write new constraint. It's really easy, I'm pretty sure even you could do it.

Martin
Life is what happens to you when you're busy making other plans.

- John Lennon

Money_YaY!
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Joined: Wed Oct 23, 2002 2:47 pm

Postby Money_YaY! » Thu Dec 11, 2003 3:04 am

theeth wrote:I posted some time ago a coding guide on how to write new constraint. It's really easy, I'm pretty sure even you could do it.

Martin
:o
Oh boy ! SOunds like a project.
I will try it for a week. If I can not get it working I will run away and scream :D
Then ask questions here again.

fun ^v^

Money_YaY!
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Postby Money_YaY! » Thu Dec 18, 2003 4:06 am

Ok Theeth. I hope that you see this. I have followed your instructions now for the simple constraints. Now what do I do? Can you supply some math that I can add to it to create the part that I have no clue of how to compute ?

Zarf
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Postby Zarf » Sun Dec 21, 2003 11:30 am

Money_YaY! wrote:Ok Theeth. I hope that you see this. I have followed your instructions now for the simple constraints. Now what do I do? Can you supply some math that I can add to it to create the part that I have no clue of how to compute ?


I began work on a constraint like this today, mostly because I wanted to see how difficult writing a new constraint that actually does something usefull would be. I had to go through and figure out some extra stuff about the new UI that theeth's tutorial didn't cover since it was written pre-2.3. Regardless just to see if the idea worked I did a quick mock-up of the code in python and it works pretty well, and Iv'e almost completed the translation into blenders source (but not tonight, I'm tired :oops:

The Constraint is only 'one-way' right now but it would be interesting to make it two-way with some way to lock either object. That way a string of them could be formed that could lead to some interesting effects.

Should have this and another small goodie to show in next couple of days.

Cheers,
Zarf


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