Even then I'd say the difference is less extreme. When I'm designing physical objects, my free-wheeling creative energies will largely be expended during the sketching phase, and when I'm in the CAD phase, that's more like coding— it's more about getting things to line up, be the proper dimension, etc. In music or visual art, what you're creating is the expressive end product, not a precisely crafted representation of the end product.
Then again, I'm not architect or mechanical engineer so maybe that's different for different folks.
Then again, I'm not architect or mechanical engineer so maybe that's different for different folks.