Select faces with wrong orientation

I got this model from sketchup. It was a mess as every polygon was doubled. I found a way to separate them but in random order. Now what I need to do is select all faces pointing in the wrong direction (in red) and deleted them. After I can merge both I will have what I need. How can I select all faces pointing inwards?

You don’t have to. Select All. Then choose from the menu Mesh->Normals->Recalculate Outside.

If your neighboring faces aren’t connected use “Merge by Distance” first.

It’s not just a question of fixing the normals. All the red faces had the wrong material and I need to get rid of them.

@ramboblender Can you post your solution again please?

If the red ones have the wrong material. Why don’t you simply select based on that material?

That’s pretty much what I ended up doing. I did a separate my material and deleted all the bad parts. :slight_smile:

Cool. Glad it worked. :+1: