Rhino has started to get the extrusion direction wrong if you enter a numeric distance for the third dimension:
Sometimes it heads in the opposite direction to the cursor (as in video). Sometimes it takes the direction according to the sign of the value regardless of the cursor position. Occasionally it works as expected.
At least since the latest SRC (7.10.21236.11001, 2021-08-24) - I don’t recall seeing this in the previous version.
Hi Jeremy - I think this is as designed - the CPlane Z determines the + value direction in Box, so that macros are predictable.
-Pascal
Hi Pascal,
In the video I create the base of the box in the World Front view. The CPlane Z is then surely the World Y? My cursor is placed to the +ve side of the base in the World Y. I enter a +ve value. The extrusion is made in the -ve direction. Who’d predict that? 
Jeremy
Hi Jeremy - Front looks at the world from world -Y
Does that make sense with what you are seeing?
-Pascal
I know it’s rude to answer a question with a question, but if I’m reading “Front” on the CPlane in the Front view is my eye in the CPlane Z negative or positive side?
I’ve always assumed (not sure why, bad habit) the CPlane +ve Z heads away from me in the Front View, but as we are seemingly on different pages I’m now questioning that assumption and vaguely recalling a right hand rule which suggests it’s actually pointing accusingly at me.
If that is the case, could it be made obvious in the help file? And given that the extrusion objects don’t follow the standard convention that you type a distance and that is used in the the direction set by the cursor, could that information also be helpfully included in the help text?
Jeremy
Hi Jeremy - Rhino’s CPlane Z is always according to the ‘right hand rule’. Front Cplane Z seen from the Front view, is poking you in the eye.
(similarly, surface normals obey this with U substituted for X and V for Y and (!) if there is no ‘flip flag’ set on the brep face.
-Pascal
How did that get past the Health & Safety guys?
You don’t have the goggles you were emailed when you got your license? Check the spam folder.
-Pascal
