A quick question for you collision detection gurus:

How do you handle sphere vs triangle mesh collision detection when the mesh is scaled dis-proportionately?

i.e. a sphere vs a mesh with a scale of (1,0.5,1.25).

When scales are uniform it is easy to just transform the center of the sphere by inverse world matrix of the mesh then scale the radius by the inverse scale. But when the scales are out, I am not sure what to do.

What is the usual response here, ban scaling unless proportional? Or is the solution really simple but something I haven't thought of yet.

Cheers, and apologies if this is a really idiotic question.