Hello, I am new to Maya, just got it last week. I'm having a small problem. I was building a human face and using the extrude edge tool a lot. After finishing a good bit of half of the face I duplicated the image and mirrored it to the original. Now when I go to edit a polygon (extrude face for example) the surface of the polygon appears empty, it shows all the surrounding edges but no face. What's more confusing is that it is not doing this on the opposite, mirrored side. Can anyone explain why this is happening?