how to change the size of a car model easily?

[defypp]

i know how to change urdf file,but it seems hard to adjust the parameters,i do not know the rules about tags like mul ，mass ，and how the size will influence the behavior。 so， i want to build a larger car based on your car.

[yangliu28]

As far as I know, there is no easy way of doing this, you have to take care of every parameter. If changing the physical size, you also need to calculate and change the collision size, mass, joint position etc. "mu1" and "mu2" tags are for defining friction coefficient in gazebo, just leave them as they are or delete them is also fine. If you need to change the size very often, you can use constants in urdf file, to avoid changing multiple occurrences of a same dimension.

[defypp]

ok，i see. thx.