Game Development Reference
In-Depth Information
OBJ is also often used as the common exchange format for static geometry, but it does not contain material or
animation data, making it less useful for directly importing into games, or at least requiring you to set up material and
shader parameters in the game engine or editor. For some tools, like the popular ZBrush sculpting tool, this limitation
does not matter because they focus on creating static geometry. The Delta Engine supports importing from FBX,
COLLADA (.
dae
), OBJ, 3ds, and DXF files, and you can use the free FBX converter from Autodesk
3
to convert among
these formats.
There are also cases where it makes sense to use a specific 3D package format (e.g.,
.max
from 3ds Max or
.mb
from Maya) if you need specific features not available in exported file formats. There is, however, a considerable
amount of work required to support those file formats, and we do not recommend them at all. If you really want to
work directly with 3ds Max or Maya data, use the built-in scripting abilities and export exactly what you need in your
own format.
In addition to the FBX and COLLADA file formats, which we'll discuss in the next two sections, the following 3D
formats are pretty common for games and in general:
•
.mb
: Maya binary file extension, used for Maya only
•
.ma
: Maya ASCII files, which can be edited with a text editor
•
.max
: Default extension for 3ds Max
•
.obj
: The object file format is a simple data format which contains 3D geometry exclusively
•
.ase
: The ASCII file format, mostly coming from 3ds Max
•
.3ds
: Obsolete 3ds Max format dating from DOS times
•
.dxf
and
.dwg
: Autocat file extensions
•
.w3d
: Shockwave scene export extension
•
.blend
: Native format for Blender; not used much
•
.X
: DirectX-specific file format, also sometimes used with XNA. Outdated and not very good
for animations
•
.ms3d
: MilkShape 3D low-polygon modeling format, mostly used for Half-Life games and
mods
•
.b3d
: Blitz3D engine file format, used by the Blitz3D programming language and its games
•
.dts
or
.dsq
: Torque engine 3D format; not used much
FBX SDK
We have talked a lot about file formats and how to export or convert 3D models, but how do you get those files into
your game? You could try to write your own importer, which is actually not that hard for many simpler formats (.
ase
,
.
obj
) and also possible for COLLADA (see next section) because you can extract only the data you actually need.
However, to fully support advanced formats and stay up to date with the latest tools, it is a much better idea to use an
existing engine or library, which can be integrated into your workflow. We decided to use the FBX SDK in addition to
COLLADA in the Delta Engine to support a number of different 3D formats coming from different tools.
3
Autodesk. “FBX Plug-Ins, Converter, and QuickTime Viewer Downloads.”
http://usa.autodesk.com/adsk/servlet/pc/
