So I've seen one or two threads on which file type people should use and most people have said to use FBX. Well I did some testing on a simple model from Google Sketch Up which revealed that out of all the file type I tested (OBJ, DAE, and FBX) that FBX had the biggest file size followed by DAE and then OBJ with the smallest file size. I then converted all these files into FBX using auto desk FBX converter 2013 (because someone told me that Unity just converts non-FBX files into FBX anyway.) Now the results showed that the OBJ file that was converted to FBX was still smaller than the other formats converted to FBX (how ever the standard OBJ file was still the smallest.) Note that this was a small, texture-less, simple model exported from Sketch Up. I also noticed that FBX had scaling issues when imported into Unity. All of them. Even the ones that were other file types then converted to FBX. However, when I took the OBJ file and converted it to FBX via Blender it worker flawlessly, unlike the OBJ to FBX via FBX converter. This all got very confusing but I walked away thinking there must be some reason everyone recommends FBX. (Unless everyone uses FBX because everyone's been told to use FBX...) So anyway, why does everyone use FBX and what are it's advantages? I know OBJ must have some disadvantages, but so far it's worked the best for me. What are the pros and cons of any relevant file types for that matter? What do any of them do differently? TLDR: What distinguishes the different file types? What makes some better for some things and some better for others? Is one just better than all of them in every way, if so then why? Actual TLDR: What do different 3D model formats do differently? What are there pros and cons of each one?