Exporting to OSG

OpenSceneGraph has its own file format (.osg). There is an exporter for Blender and it can be found:

http://projects.blender.org/projects/osgexport/

If you have difficulties with download, use wget (file was corrupted when I downloaded it with Firefox).

wget http://projects.blender.org/frs/download.php/333/osgexport-2.42b.tar.gz

Extract and copy osgexport-2.42.py to your .blender/scripts/ directory.

First osg-export

Some checks before export:

• There is no support for multiple materials in same object in osgexport (see exporting multimaterial objects).
  
• Check normals! Normals should point outwards, otherwise surfaces are rendered as black. You can use Flip Normals or Recalculate Normal Outside to correct problems.
  
• Check Center points of the objects. For example if you want to rotate a door programmically in OSG, you set Center point where the hinges are.
• You could also apply scale and rotation (Ctrl +A). That saves few transformations and makes osg-files easier to read (for a human).

Export

When you are ready to export, just choose File -> Export -> Openscengraph (.osg).

• Type the path and the filename to the Output File textbox
• select the items you want to export
  
• press Export.

Then just open terminal and type: osgviewer name_you_gave.osg

Exporting multi-material objects

If you export object that has multiple material indexes, only the first index is used. Therefore you have to export them as a separate objects.

Here is a typical example:

1. Enter in Editmode (Tab).
2. Press P (Separate) and select by Material.
3. That separeates objects by material but it doesn't remove extra material indexes so you have to remove them manually.
4. Then export as usual.

NOTE: There is a fast way to test how materials are shown in OSG. Make sure that Game -> Use Blender Materials is not selected. Then just press (P) over 3D-window. That starts Blender's game-engine and because that also doesn't support multi-materials, you can have a preview how things will look in OSG.

Texture baking

With current cvs-version of Blender textures can be baked to the uv-map.