How do I change the default coordinate system in Rhino?

Hi All, is there a way to change the default coordinate system in Rhino?
I am doing a Grasshopper Interface for Sofistik but I would like to change the Default UCS of Rhino with a coordinate system with x pointing on the right, y pointing downward and z pointing inside the monitor (right end coordinate system with z positive for gravity)

There is a way to do this?

Best Regards

I saw in the guide for Rhino5 (OSX indeed) that the World Coordinate System cannot be changed.
Can you confirm this?

I’m not sure what you’re trying to achieve - it sounds like you want the viewport to have a Bottom view.

no, basically I need that if I draw a line (vector) form 0,0,0 to 0,0,1 his direction must be downward (conseder a perspective view).
I need this to better couple Sofistik FEM with GH and Rhino

Sorry, no. The right-handed, Z-up, Cartesian coordinate system in Rhino is not something that can be changed.

ok, thank you

Since you are asking for a Right-handed coordinate system, you can just change the way you look at it, as Menno suggested.
Run SetView CPlane Bottom to get the view you asked about.
I think there’s a bug in SetView - Setview World Bottom should do it, but doesn’t.
Or maybe I’m confused. I’ll see if I can verify that.
For now, try SetView CPlane Bottom and see if it does what you want.

If you follow Lowell and Menno’s suggestion, then you can use Construction Plane Coordinates, then you’ll need to manage which viewport is current and if it has the CPlane set where you expect it to be… The additional risk is the user of your tool may delete, replace, or change the CPlane in the viewports and take your coordinate system with it. Just lots more to manage and check in a plug-in.

I’m talking about not changing the CPlane at all - keep it in the same orientation to world coordinates - Just look at the whole thing from the bottom.

Yes you are right :smile:

Thank you