   What should I use?
  I don't have any artist to create a models for me. But my engine is quite good, I think. I have already implemented many things like resource manager, scripting, and scene graphs. I tried the md2 but it is already outdated and it is not using bones. MD3 is quite good but looking for free models in the internet is pretty hard. I tried collada but it is very hard to understand. Now, I'm stuck on this problem. What should I use? I just want to make a 3D rendering engine that have a good graphics for today's game. Can anyone recommend one?   
  Are you asking for a model format to use?  If so, I am using the Milkshape3D format for my engine.  It's pretty cheap to buy, and the SDK comes with sample code for loading their models.   ;  Might be good. (newer tested myself)http://www.caligari.com/downloads.htmlfor format I suggest FBX (you can download SDK from Autodesk some registration is neaded)/Tyrian   ;  I'm still confused on what to use on my engine. I'm using Doom 3's file format right now. So far I don't have any problems with it.I'll try the Milkshape3D and FBX later. Thank you very much for the suggestion.   ;  If you want a generic format without a restrictive license, try Collada. It may or may not be an overkill, depending on the scale of your project.   ;  I'd say go for COLLADA. It's open, supports many features and is easy to parse using COLLADA DOM. In fact I just implemented a COLLADA loader for my own 3D engine. If you need help, I'm sure there are a lot of people in this forum who can help you getting started.   