usd renderer using lowercase

[cadop]

I think it would be good to change:

warp/warp/render/render_usd.py

Line 75 in 1535cde

self.up_axis = up_axis

to

     self.up_axis = up_axis.upper()

and use capitals here:

warp/warp/render/render_usd.py

Line 100 in 1535cde

if up_axis == "x":

USD doesn't like lowercase, and this caused an issue for awhile when I was trying to render with warp. For example, this modification to the sphere fails

        if not instancer:
            if colors is None:
                instancer = UsdGeom.PointInstancer.Define(self.stage, instancer_path)
                
                # Create a capsule instead of a sphere
                instancer_capsule = UsdGeom.Capsule.Define(self.stage, instancer.GetPath().AppendChild("capsule"))
                instancer_capsule.GetAxisAttr().Set(self.up_axis)
                

because GetAxisAttr() expects capital, but warp expects lowercase.

[mmacklin]

Ah, thanks @cadop - sounds like a good change. @eric-heiden .

[eric-heiden]

@cadop Thanks for reporting this, the up_axis parameter will be in upper case in the next release.