Sorry for the delay, lots going on in my world.
GREAT question, with a not so strait-forward answer.
Generally in CGI, eyeballing is the name of the game. Why? Because CG is art and artists eyeball everything. However, there are cases where eyeballing is not acceptable.
For example, say I’m working on the stadium’s podium, a background prop that barely gets seen, I’ll do that model without looking or caring about any of the vertices positions except I will make sure that the bottom of the object is aligned to zero. I’ll also pay attention to symmetry, but as you’ll discover that is easy.
With this said, proportions are extremely important. What I mean is, if something is noticeably off, you got a big problem.
Things that you SHOULD pay attention to and create accurately are things like the field, game objects, etc. The robots can be fudged a bit, just make sure the wheels actually touch the ground plane.
I would recommend working in a real unit scale if using 3ds max. Generally you might want to start with an accurately sized primitive then use it to create a less accurate finished object.
One thing that you’ll find is that CG is perfectly capable of creating exactly perfect models, materials, etc. Once you master this, you may go after a more realistic sense, meaning you begin to realize that “perfect” looks wrong. Because the real world isn’t perfect.
Hope this half-way explains that, watch what the instructor pays attention to and what he doesn’t.
-Cody