Quote Originally Posted by curious aardvark View Post
colours are pretty pointless.

Transparency is potentially useful if you're designing mechanisms within a shell. Otherwise - again - just unnecessary window dressing.
haven't used it yet - or felt any need to.
I usually use a difference() to look inside things. I subtract off a huge cube([]) so I can see a cross sectional view of what is being built. I have a couple of examples, like a whistle and a pump jack where unless you can see inside, you won't know that you have things right.