Some days ago I wanted to get some information on how OpenSceneGraph internally performs the rendering, to prepare for my B.Sc. thesis. Especially I wanted to know if it really uses Vertex Buffer Objects when I “force” Graphics Nodes to do so. Code analysis would have taken to long and would not have been proof enough for me. Thus I needed an OpenGL debugger. A nice one I found is glsldevil, which was developed at the university of Stuttgart. It can not only debug pure OpenGL, but also GLSL shaders.

glsldevil

For gentoo I found an old ebuild somewhere in the web and modified it for the new version of glsldevil. Here is my overlay including the modified ebuild: glsldevil-1.1.5.tar.gz (361)

Download the overlay and extract it in /usr/local/portage. Be sure to include the following line in your /etc/make.conf:

PORTDIR_OVERLAY=”/usr/local/portage”

Then emerge glsldevil.

regards

Jürgen

Posted in 3d, gentoo, linux, programming, science, tools | No Comments »

I just recognized the osgocean release on the osg mailing-list. Osgocean is a library that one can use to render water effects in a very realistic way. It was used to generate the above and below water effects in the VENUS project. For more information on the osgocean project see: osgocean You can see how realistic it looks if you watch the youtube video below.

It looked very interesting, so I decided to try it out. To do so I wrote two ebuilds, one for osgocean and one for  fftss, the fast fourier transformation library it depends on. Both are available in following archive: osgocean overlay (294)

Extract the archive to your portage overlay.

# mkdir /usr/local/portage/
# cd /usr/local/portage/
# unzip osgocean_overlay.zip

Be sure that PORTDIR_OVERLAY=”/usr/local/portage” is included in your /etc/make.conf, then you can emerge it:

#emerge osgocean

For this you need to have the OpenSceneGraph library installed. Detailed Instructions on how to build OpenSceneGraph on gentoo can be found on PlopByte.

Since openscenegraph is now in the main portage tree I updated the ebuild dependencies today (31/08/2009) to either media-gfx/openscenegraph or dev-games/openscenegraph.

Updated ebuild is now available here: osgocean-1.0.1.ebuild (200) Just copy it to /usr/local/portage/media-gfx/osgocean/ after extracting osgocean_overlay.zip like described before and run:

ebuild /usr/local/portage/media-gfx/osgocean/osgocean-1.0.1.ebuild digest

Best regards

Jürgen

Posted in 3d, gentoo, graphics, linux, programming, science | No Comments »