I recently ordered the book Focus on 3d Models but until I recieve it I was hoping to find some more information on 3d model formats. I guess first of all, is there a standard? The closest thing I found was X3d which is xml based (I like the human readable part but is the overhead worth worrying about?) and I can't get the import script to work in blender. It seems like a lot of people use .3ds, but isn't that proprietary? I am hoping to find something that isn't restricted or needs a license to use and is blender friendly. I've tried some searching for information on 3d model formats but keep coming up with site that have models for download so any information or links to appropriate sites would be greatly appreciated.

3ds is technically proprietary but well documented (and it's so ancient that nobody really cares). It's not a very good format though for modern stuff so if you *can* stay away, do :)

I don't have too much experience, but I'd look into the .X file format (especially if you're using DirectX, but even otherwise). Also .OBJ (Wavefront objects) are decent for raw geometry info. I guess it really depends what you want to store :)

Beyond that, there are a few good pointers on the PolyTrans site (http://www.okino.com) and if you can afford it, PolyTrans is a great way of converting to and from your file format preferences.

What are you planning on doing with the models? Most game engines have specific formats that they recognize which restricts you to those (or if you have a tool like PolyTrans, it's a bit more flexible). Perhaps some more information would allow me to answer the question more suitably.

Cheers.

To start with I am not using DX so I hoped to stay away from .x I plan on using OpenGL and am not building off of an existing 3d engine so I can impliment pretty much any format I want. What I want to avoid is any proprietary formats, even if they are old [WINK]. Other then that I don't really have any requirements. Currently the models will be for a small game engine (2d scroller with 3d models). I DO like the idea of x3d and it should be relativly easy to write a loader for it but as I mentioned I am concerned about the overhead involved.

If it helps I was hoping to find the .ogg and .png of 3d models. [grin]

Well the overhead of XML-based data is huge (on the order of 10x larger/slower), there's no disputing it. You'll see it both in file size and in load time. That said if you're using small models it won't matter too much. I'm not sure that I'm sold on using XML for a geometry format since there's really no reason for it to be human readable/editable.

Also don't dismiss the .X file format merely because DirectX has built-in support. I'm currently using OpenGL and strongly considering using .X files simply because they include everything I need in them, and have text, binary AND compressed (tokenized) versions. They also look pretty straightforward to load. Lastly you can take advantage of the great optimization algorithms that DirectX has a EXPORT-time, and reap the benefits when you load it up without any extra work :)

That said I'm sure there are plenty of other suitable formats, but .X seems to do geometry (with normals, etc), animation (with skinning), materials, and the like quite well.

"I'm not sure that I'm sold on using XML for a geometry format since there's really no reason for it to be human readable/editable."

If I remember correctly, Red Faction used a format for maps that could be created using a text editor. I would agree though that there shouldn't really be a need to be human readable. Is the .x format proprietary? It probably wont be an issue in any case but I would like to try to avoid any proprietary formats.

Quote:

Original post by tstrimp Is the .x format proprietary? It probably wont be an issue in any case but I would like to try to avoid any proprietary formats.

I do not think so, but don't quote me on that. In any case it's fully documented and I don't think there are any restrictions on using it in your own stuff.

Hello,

.3ds has alot of restrictions and yes its very aged.
.x3d rather rare format
.obj (Wavefront) very nice geometry
.x very nice, optimized and fast format for DirectX appilications, can be viewed with texteditors. A negative side - no vertex animation.
.ase (ASCII scene). Seriously no clue what it is, but I think its worth investigating. I know a few people who really like that and use it to convert data to their own formats.

Good luck with it ;)