constraints

[nathangallegos]

this is the rig set up that professor Watkins went over today in 3d4...... if anyone has anything to add ( notes, or suggestions) please post here

[Dashmore]

Thanks heaps. This will rally help and provide future reference.

[Professor Watkins]

Note a few things about this rig:

1) It has IK set up for the arms. It uses two IK chains: one from the shoulder to the wrist, and one from the wrist to the hand. This allows us to keep the hand stable so the hand doesn't turn as the Wrist IK moves.

2) The IK handles for each arm are grouped.

3) There are four (that's right four) locators. One for each hand in the air (2) and one for each side of the box.

4) The hand IK groups have Point constraints for both the Air Locator and the Box Locator (for both R and L).

5) The point constraint is animated over time when it becomes time to grab the box.

6) The arms are animated by animating the Air Locators. These Air Locators drive the position of the group of IK handles which drive the rotation of the arm joints.

7) Notice that once the Arm IK groups are contrained to the box locators, the arm rotation is all driven by the box. Moving, rotating, etc....will drive the position and rotation of the arms.

Hope that helps.

[Otaku_Zero]

in number 4 you say the hand IK groups have point constraints. Is that the entire arm group that has the constraint, or just the hand IK handle for each hand?

[Professor Watkins]

In each case that uses constraints, it's the group (that contains both the arm and hand IK handles) that is constrained to a locator. Be sure to check out the .mb file too.....

[Professor Watkins]

OK....here's an experiment to see if this helps.

I've created a quick video tutorial of the basics of this technique. It doesn't spend a lot of time refining animation (i.e. there is no clavicle animation), but it does show the basics of the constraint solution to the problem.

Give it a look and see if a) it makes sense and b) if this sort of video tutorial is a good method to answer questions.

Heavy Box Constraints Demo

[Otaku_Zero]

my vote is yes, that is very helpful. sometimes language gets in the way of ideas and i think showing is almost always better than telling.

How hard was that to create? other than the actual going through the motions.

[Jacqueline]

A: Yes, it makes sense

B: Yes, I think it'd be a really great way to answer questions

[jthep]

cool

Yeah i think this video experiment is a great way to visually show what you are talking about

[Professor Watkins]

Continuation....

This is a (pretty raw) video tutorial on giving the box to a second character and how the constraints would work out.

Passing Heavy Box Video

[Professor Watkins]

...and here's the file....