Making a 3D model of something with pictures isn't something new to most of us, but there have been a lot of people getting into drones recently and I wanted to show something useful you can do with your drone. Autodesk's 123D Catch has a very useful feature not everyone knows about; Once you have your 3D model ready, you can input a known measurement and 123D Catch will scale your model based on the known measurement. If you're having trouble figuring out how long your Christmas lights need to be, your drone and 123D catch can help. Lets see how long the Christmas lights need to be for the 3DR Building... Lets start from the beginning. We want to get pictures of all angles of the building with a bit of overlap, if possible we want to get some at different elevations to help the 123D Catch build a better model. I'm going to be using a 3DR ArduCopter Hexa-B and a GoPro Hero2 (A camera without a fisheye lens will probably yield better). Plotting your mission using the Mission…