Perpendicular / Normal Extrusion Confusion

it’s neat seeing @arail in this thread because it might explain where the requested behavior is coming from…

he and i are both coming from a sketchup background… ExtrudeSrf (and MoveFace in some instances) are the closest thing to sketchup’s push/pull tool so it’s possible we have a different way of approaching modeling based off past experience…
i’ve been able to rethink a lot of the ways i draw due to me using rhino -or- adapting to the way rhino is designed but in this case, i’m not entirely convince wanting to extrude several curves or surfaces in a direction normal to their plane is a flawed method…

but hey, we can only push/pull one face at a time in sketchup even though it’s been requested behavior for at least a decade :wink:

i’m used to it but this is rhino, you know? not sketchup :smile:

Jeff -

I didn’t think of it that way but now that you point it out, I see that you’re correct - I’m assuming a ‘Group Push/Pull’ operation.
I’m surprised that the assumption is the extrusion would be normal to the CPlane and not normal to the surfaces. I can’t think of where that would be useful. The alternative - group extrude normal to each individual surface - would be useful in many situations, not least for any complex shape formed by a rib structure (i.e. your work).

Well, I described how V4 works, and until this thread, I thought V5 also worked - I am suggesting that at the very least, things should go back to V4 behavior so it is at least more predictable, and add Jeff’s request on top of that, if it seems like a good idea.

Agreed.
I’m new to Rhino V5 so I don’t have V4 experience and didn’t quite see that’s what you were driving at.
Thanks for your input on this (and sorry to have hijacked Jeff’s thread a little bit)

Try Offset Surface! It worked for me solve a similar problem.