Gas Pump Model

[danf]

I'm using the stock Gas Pump model from the A:M supplemental DVD.

 

It has a skeleton on the hose so it can be manipulated. My problem: I can't seem to manipulate it gracefully. My reasoning tells me I should be able to put some kind of constraint on the handle so it stays in my character's hand, but it never seems to work right. So I'm stuck with this hose that is constantly flying around, twisting my handle during inbetween frames, and generally giving me a headache.

 

I actually finished a whole shot doing the nozzle frame-by-frame. It just feels wrong.

 

What's the answer?

[John Bigboote]

Rigging dilemmas!

 

Did you check to see if there was a pose with the model that would turn ON constraints? There probably is not though... you WILL be experimenting then. Look for the old octopus tentacle rigging tutorial called 'Bendy Legs'- that shows how to use orient-like and constrain-to constraints to get a forward kinematic sort of chain where you grab the last bone and pull and the others follow. You will also want to experiment with the dynamic-constraint so do some research on that as well... I know you can get nice 'dangly' response using it, but you will want more control. You may also want to consider ditching the bones and try using the new SimCloth feature...

 

Sorry- no automatic answers...perhaps other Hasher's will though.

[danf]

I like the cloth idea a lot. I'm trying to upgrade the pump with a cloth hose, but right now there's one problem: When I grab the nozzle and move it, the cloth seems locked at the next spline. Is it normal for cloth to only act like cloth between splines, which still act locked in place?

 

How would I go about unlocking the hose splines to react to gravity like cloth, or is that a different thing, and I should take off the splines and replace it all with a saggy cloth spline?

[robcat2075]

In the tech Talk on dynamic constraints I believe there is a part on chains that hang from two points, which would be what you are trying to do.

[danf]

Oooo, I've felt like a Newbie until now! My first question that requires venturing outside of the Newbie forum!

[robcat2075]

possibly simpler solution:

 

hose.mov

 

 

the hose is a chain of bones with a Kinematic constraint to follow the nozzle, but they are all also Aim At Constrained to point to the "bottom target" null to make the hose always hang down.

 

They are also all Aim Roll At constrained to "HoseRollTarget" to keep them from flipping sometimes.

 

"HoseRollTarget" is constrained to float 50% between the two ends of the hose

 

you animate the nozzle first, then move the "bottom target" at each keyframe to make the hang of the hose look right. All you animate is those two bones, the rest take care of themselve.

 

more hose bones and more spline rings would make for a smoother looking hose.

 

MDL and CHOR you can examine.

 

hose.zip

[John Bigboote]

Wow Rob--- It's Saturday night and I have a buzz...but I can't wait to look at how you did that more in depth...maybe over morning coffee- THAT LOOKS GREAT!

[danf]

Okay this is probably me regretting skipping the bowling tutorial, but how do you create a target,

 

and more specifically (since I was able to copy/paste your target):

 

how do you create a "Roll Target" that stays between two points like you've done?

[danf]

Really, just the gravity null was enough to relieve the headache, I could keyframe the remaining problems out of existence without frame-by-framing it. Thanks so much for this, even though I only understand some of it.

[robcat2075]

how do you create a "Roll Target" that stays between two points like you've done?

 

In the model the roll target null was placed at the beginning of the hose, and then"Translate To" constrained to the nozzle bone.

 

That makes it jump all the way to the nozzle, but setting the enforcement to 50% makes it jump only half way.

 

It probably isn't necessary but in my initial test some of the hose segments were flipping as i moved the nozzle. I wasn't sure why, but I just eliminated that entirely by making them all point their roll handles at that null.

 

on the actual gaspump model it will probably be best to adjust the spline rings and bones on the hose so they are evenly spaced.

[danf]

Oh that makes way more sense- the part I didn't realize by looking at your models was that you first placed the null by the hose start. That makes a ton of difference. I thought you made some dual-constraint where it was bound equally to each, which I'm sure is somehow possible, but I don't need to delve into right now.

 

The funny part is what a small portion of a short shot this hose actually is- This rigging system just prevents it from DOMINATING the focus of that moment.

[robcat2075]

Oh that makes way more sense- the part I didn't realize by looking at your models was that you first placed the null by the hose start. That makes a ton of difference. I thought you made some dual-constraint where it was bound equally to each, which I'm sure is somehow possible, but I don't need to delve into right now.

 

Since the starting point of the hose never moves, one 50% constraint will work.

 

If you were trying to float between two moving points, two 50% constraints would probably be needed. (I think two 100% constraints would do as well)

 

The funny part is what a small portion of a short shot this hose actually is- This rigging system just prevents it from DOMINATING the focus of that moment.

 

Yes.

 

And that's why character animators spend a lot of time trying to get their characters move in a natural way, rather than float/move between poses. The floating looks odd and distracts from the performance of the character.