Last year I got to sculpt (and articulate) Transformers RED Shockwave! Designed by @DantheArtguy apparently! Some things are tweaked and changed by engineers between sculpt and production.
@WaffleyMan Working with physical clay is a tremendous skill and it can totally transfer to CG if you work at it. Blender is a decent free program that allows for high poly sculpting if you're feeling ambitious!
I got to work on Terrorsaur! The organic bits, at least. I had to be careful about not altering the articulation, and stick close to the control art, which wanted him as pretty gnarly.
@Stay70573 I can measure within the software but it's probably unreliable. Once it's handed off to the engineers/manufacturing folk, there's a bunch of small edits to make sure it prints correctly.
@decepticonaiden Thank you! I used Zbrush. I'm not 100% sure but I think the machinery is made using the CAD software under the PTC umbrella by people way smarter than me, lol.