Chandra’s Page

I started playing around with OGLE (OpenGL Extractor) the other day, and it’s so far proven to be a marvelous tool. The basic idea behind OGLE is that it grabs geometry from inside Second Life (or most other OpenGL-based 3D applications, for that matter) and spits it out as a Wavefront .OBJ file, a format understood by many 3D modeling programs.

Setup was fairly simple. OGLE relies on another tool, GLIntercept, an OpenGL extraction and debugging tool, to do most of the heavy lifting, so that needs to be installed first, but the whole installation process was all of five minute’s work. OGLE comes with a default configuration file that works quite well for capture in SL, so after coping a couple of files to the Second Life directory, it was all ready to go.

As you can see from the screen captures, the objects in SL are captured quite faithfully by OGLE, and Blender does a decent job of bringing the resulting .OBJ files in without mangling them. The files did require a little cleanup once inside Blender, mostly because OGLE pulls in every object that’s currently visible in the scene when you capture a frame, and a few that are present but aren’t normally visible, such as the world skybox, clouds, and even hidden HUD attachments. A word of advice: if you want to spend less time cleaning up a model once it’s in your 3D modeling program, take your pictures well away from objects you don’t want to capture, and remove your HUD attachments. I popped up to 740 meters altitude for these captures, which worked quite well.

I did find that most, but not all, of the meshes that make up the Damselfly were brought into Blender as duplicates, so I had to do a bit of deletion to further clean up the model. I suspect this might have to do with one of GLIntercept’s options that captures a pair of rendered frames for comparison, a tool useful for debugging, but not quite as helpful when capturing a single frame is all I need. GLIntercept and OGLE have a cosmic butt-ton of options to set, so there’s probably a way to avoid the duplicate geometry.

What good does this sneaky bit of geometry capture do me? Well, aside from being able to send my avatar or objects to a 3D printer, like that used by Fabjectory, I’ve now got the option of using all the tools available to a good modeling tool, like subsurface modeling, materials, and complex lighting and rendering options, to make creations from Second Life into photorealistic art.

More interesting to me for SL, tough, is that prims come through the process as their own individual meshes. I can use the UV map generation tools in Blender to unwrap the polygons that make up an object, then lay them out flat, creating a custom texturing template for Photoshop. This should make texturing some of the more tortured prims, like the tori that make up the Damselfly jet engines, a much more precise process. Anything that takes guesswork out of the texturing process not only saves on upload fees, but also on time and frustration.

This entry was posted on Friday, October 6th, 2006 at 5:29 pm and is filed under Building. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.