使用OpenSceneGraph(OSG)库将osg模型转为obj格式

-O option

ReaderWriter option

--compressed

Compress textures.

--compressed

Enable the usage of compressed textures.

--compressed-arb

Enable the usage of OpenGL ARB compressed textures

--compressed-dxt1

Enable the usage of S3TC DXT1 compressed textures

--compressed-dxt3

Enable the usage of S3TC DXT3 compressed textures

--compressed-dxt5

Enable the usage of S3TC DXT5 compressed textures

-l libraryName

load plugin of name libraryName i.e. -l osgdb_pfb 
Useful for loading reader/writers which can load other file formats in addition to its extension.

-e extensionName

load reader/wrter plugin for file extension i.e. -e pfb 
Useful short hand for specifying full library name as done with -l above, as it automatically expands to the full library name appropriate for each platform.

-o orientation

Convert geometry from input files to output files.
Format of orientation argument must be the following:

X1,Y1,Z1-X2,Y2,Z2
or
degrees-A0,A1,A2

where X1,Y1,Z1 represent the UP vector in the input files and X2,Y2,Z2 represent the UP vector of the output file, or degrees is the rotation angle in degrees around axis (A0,A1,A2). For example, to convert a model built in a Y-Up coordinate system to a model with a Z-up 
coordinate system, the argument may look like 

0,1,0-0,0,1 
or 
-90-1,0,0

-t translation

Convert spatial position of output files. Format of translation argument must be the following :

X,Y,Z

where X, Y, and Z represent the coordinates of the absolute position in world space

-s scale

- Scale size of model. Scale argument must be the following :

SX,SY,SZ

where SX, SY, and SZ represent the scale factors. Caution: Scaling will be done in destination orientation