Is driver influenced by scaling an object?

Hello,

i tried to use a driver to make wheel rotates accordingly to its move. But when wheel is scaled up or down, rotation changes is not coresponding to size of wheel, it´s not synched. Is there any solution to solve it?

Without knowing exactly what your model looks like, how your rig works or the exact driver expression you used, nobody will be able to help you. Post your .blend.

Hi,

generally speaking no. Scale happens at the end of the transformation order (translate->rotate->scale) and this is fixed in Blender as far as I know. However it’s absolutely normal that your wheel would turn slower when it is bigger. If you have rotation in radians A as a function of the translation of the body of the car B and the diameter of the wheel D your driver expression should look like 2pi * D * B (create B and D as variables in the drivers window, B should be an axis translate value and D should be rest length of your wheel’s radius divided by object scale)

Hadrien

There is link to blend file. I am new user co I can´t upload attachments.

When You grabs an empty in X axis, wheel is rolling. I scaled it down a lot to exaggerate the effect.

driver.blend

I was already started on an example file so I’ll just send you that : http://pasteall.org/blend/index.php?id=51221
Open in 2.8 for correct dependency handling (in 2.79 the wheel object has some lag)