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Xpresso rotation change problem
I’ve set up a scene with a robot with wheels. I made a small xpresso kinda rig, so when I move a null the robot moves with it and the wheels rotate as well. Which is all fine, but when i move the position to the center axis and keep going in the same direction. The rotation direction of the wheels start to go the completely other direction.
Its clear that it changes when it moves by the 0,0,0 point.
Does anybody know why this happens? -
8 Replies
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can you post the file? (or a cut down example)
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Just posted it, I removed most of the body.
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In the xpresso on the wheels change the Move parameter being passed from Position (3) or Global Position (1) to Global Position.Z – Position or Global Position don’t make much sense with that setup as you get wheel rotation moving straight sideways or up/down as well. Would work ok as long as the vehicle remains level. You may want to use a path (spline) type drive system if you are going to be turning corners – or place the Move inside a Rotation null so you can always move in Z and the Rotate handles direction
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Thats exactly why I put just “position” instead of “Z-position” I wasn’t sure to make it able to turn around corners cause the wheels wouldn’t turn the right way. Would a rotation NULL fix that?
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I can’t get a rotation null to work, still won’t rotate the wheels when the body is on the other axis…
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path spline I would say, unless you have a grip on the math to do delta forward distance in vehicle Z. There’s a reason there are plugins dedicated to vehicle movement. The other way to do it would be dynamics
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I just figured out a way to make it work!
Thanks for the help though!I ended up putting the “move” inside the “the parent” (the top of the hierarchy)
So whenever I move the Parent in Z the wheels rotate. Because the “move” follows obviously.
Then in the Parent i did the xpresso “Global position X” into the “position” in the “move” with a “range mapper” and a “math: multiply(input sat to -1) ” between.
It works like a charm for some reason.
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