Solids appear to have no sides?

Rhino for Windows
#1

test.3dm (752.0 KB)

Could someone help, I have extruded some staicase treads and risers whic are a block instance, when viewed in the block they appear solid with all sides presence as soo as I close the block they appaer to be like a wireframe although Iam in shaded view?

thanks

#2

It’s not quite wireframe - it appears inside out. If you block edit them, explode them and rejoin them they appear to be turned the right side out.

#3

yes thats it ! thanks, not sure how that happened but that worked

#4

My guess is the block instances may have been mirrored at some point, is that possible?

-Pascal