I built an orthophoto of a large area of land. In the model it is shown correctly with the cameras placed in the correct spot and situated above the model like they are supposed to be. However, when I export an orthopohoto, the result is flipped inverse of what the model shows and what the ground looks like in real life. In other words, it looks like the program built the orthophoto from the back side of the mosaic. It has done this whether I align photos using generic or ground control. I have never had this problem before. Any ideas on what is wrong?