Automatically flipped faces

SketchUp
1

Hi,

In SU2017 Pro;
I’m having a little problem with flipped faces. When I draw a new rectangle or circle, it automatically is flipped (the gray color, not the white). I guess it’s an easy fix on an adjustment I’ve done, but I don’t find the error. The program worked fine earlier today.

Regards R

2

If you are drawing a face on the ground plane, it’s normal for its back face to be up. This is not an error. When you make it 3D the face orientation will be correct. Think of it as looking at the inside of the bottom face before you make it 3D.

3

Thanks DaveR,
Please see the screen shoot;

1976×1481 57.2 KB

4

Yes. It’s normal for the back faces to be up when you draw on the ground plane. It’s not a problem though.

6

There’s an explanation: the SketchUp designers concluded that when you draw a face on the ground plane it is probably going to end up being the bottom of some 3D object. When that is true, you want the upward-facing side of the face to be inside the object, that is, for the “back” surface to face upward. So SketchUp forces it to face that way.

This conclusion doesn’t hold if the face is off the ground plane, and indeed, SketchUp doesn’t force the back surface upward then.

7

That kind of make sense, thanks!