Need help with animation

# 1 27-04-2003 , 01:42 AM

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Join Date: Apr 2003

Location: North Delta, BC

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ok, i am trying to animate a motor. I want the piston to move up and down the cylinder when the crankshaft rotates. I can get it to do this motion with set driven keys, but it wants me to set the keys for every damn part of the rotation (ie. it doesn't repeat after going past 360 -since it says 390, 440, etc) Is there a way to repeat these keys?
Then i tried this with bones and IK handles, but that doen't work since the IK won't loop around itself.. it really hard to explain, so how about someone just tell me how to do it.. lol

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# 2 27-04-2003 , 01:47 AM

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Just go to like, frame 1 billion, and set the rotation to like 50,000 degrees. LOL. You get the idea.

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# 3 27-04-2003 , 07:58 PM

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Or even better.. set the curve for the driven to pre- and postinfinity cycle with offset!?! :banana:

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# 4 28-04-2003 , 06:24 AM

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what is this cycle post infinity?? I want to be able to make it rev up and down... so i don't really want the exact same keys repeating itself. Im stuck, and animating each of the 6 pistons going about 1000+ rpm or so... is totally out of question.

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# 5 28-04-2003 , 10:23 PM

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You are only repeating the setdriven key relationsship. You can key the "Driver" any way you want.

Example:

Locator ry drives Box ry.

Two keyed relationships:

*Locator: 0 and Box: 0
*Locator: 360 and Box: 360

When you rotate locator above 360 box stops following!

NOW:

Select the box (driven) and go to the graph editor. Find the keys/curves for the setdriven relationship and mark them. Go to curves pre- and postinfinity and set them both to "Cycle with offset"

Now you can rotate the locator past 360 and past 0 in the negative and the box just keeps on going!

By the way the you could maybe do this smarter with constraints, like the aim for example!

If you want to rev up and down the engine maybe play with the tangents in the graph editor.. awsome animation tool!

Just some thoughts.. Have fun and let's see the result!

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