View Full Version : Rigging Issues

05 May 2010, 12:13 AM
I'm animating a scene where I have a character using a two handed prop and he shoving some cow mature, and then he basically turns around and throws the shovel into the ground then leans on the shovel. For the next 300 or so frames he acts out some dialogue.

I have rigged the prop for a two handed prop but I'm having problems keeping the shovel in the ground and not have to counter animate the shovel on each frame, is there an easier way of doing it???


05 May 2010, 07:02 AM
Theres a couple ways you could do this:

1. Parent constraint with a blendable weight the shovel to the hands and to the ground. On the frame where he drives it in, blend to the world weight.

2. Visiblity switch between two seperate shovels (or shovel rigs). Its only mildy hacky, and wont work for a game environment, but if your rendering it out, should be fine. Though, if your doing motion blur, you'll probably need to watch the switch frame and render out a frame before and after for each shovel as to get the proper interpalation.

Good luck.

06 June 2010, 02:31 PM
As stated there are a number of ways to achieve this effect. It really depends on what the end goal is and what platform you are doing this project for. Is it for an animation, game, short, Commercial, etc...

Each one has different limitations and requirements. For most, the end result is all that really matters.

The oldest trick in the book however is to have two shovels. When he plants the shovel in the dirt you have the camera focus on something other than the shovel. Set the visibility of the shovel in the hand to Off. And turn the visibility of a second shovel already planted in the dirt to On. Then when the character goes to pick up the shovel again you simply reverse the process. It's an old slight of hand technique.

06 June 2010, 03:54 PM
Sorry guys I got busy and didn't notice that people were paying attention to my post, but to address your questions yes its for character animation in film(demoreel), and no I can't do the swap trick cause I can't have a camera cut so it wouldn't work in this situation.

06 June 2010, 04:03 PM
The swap can be within a single Frame. You don't have to cut the camera. Just Change your focus. Centering the focus is much different that doing a camera cut.

If you stack both shovels on top of each otehr so that they are matched, Using a stepped curve to turn the Visibility on and off in a single frame, you will not be able to notice the switch. If you shift the camera focus with a bit of help from lighting you should not be able to tell that a swap was made.

06 June 2010, 07:24 PM
Here is a sample file of the slight of hand trick.

06 June 2010, 02:45 AM
The old swaperooo can work just fine if you nail the swap frame.
But just one more idea to put out there...
One suggestion I got a few years back for cases like this was to constrain the hands to the object...instead of the object to the hands.
Most rigs should have a parentable group/locator above the hand control so that you can just parent that group/locator to the object and still freely animate the hands if need be. This is the best way I have found to get the most control over your object. In my opinion, it makes it worlds easier to create good arcs and also plant an object when needed.
Hope this helps.

06 June 2010, 11:40 PM
I think I got it pretty much rigged, thanks for all your ideas thou.

But is there way to do what the diagram is asking???

06 June 2010, 03:37 PM
there are a couple ways to do that.

First you can run the translate of Red X to a multiple/Divide node then use the output from that into the rotation of the Blue +

or you can write an expression that does pretty much the same thing.

or you can set up Some SDK (Set Driven Keys)

06 June 2010, 04:00 AM
there are a couple ways to do that.

First you can run the translate of Red X to a multiple/Divide node then use the output from that into the rotation of the Blue +

or you can write an expression that does pretty much the same thing.

or you can set up Some SDK (Set Driven Keys)

How would you do the SDK in which range would you key the SDK's?? 0-180 with each axis???

06 June 2010, 08:18 PM
The first questions is actually how much translation do you need per rotation.

is it a 1m to 15 degrees? 45? 90? 180? 360?

All of these are certianly possible it is just a matter of how much.

you would take object A and object B.

Set both at Zero. Select Object B (the rotation) and select Set Driven Key form the animation menu. This gives you the Set Driven Key Window. The Driver is going to be, let's say Rotate Y of Object B. Then Driven is let's say Translate Y of object A. Select both of these values in their respected menus. Making sure that everything is at Zero, select Key.

This is your Base Value.

Now set the Hieght of Object A in Translate Y to 1, and the Rotate Y of Object B to lets say 45. Back to the Set Driven Key Window and select Key.

Go ahead and close the window.

Select Object A. and Open the Curve Editor. Select the Translate Y Curve Tangent. (The Green Curve) and set the Post and Pre Infintity under Curves to Linear.

This will allow you to Rotate Object B in either direction and Object A will Behave.

Attached is a Maya file where I did exactly This and achieved the result =)

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06 June 2010, 08:18 PM
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