Tuesday, 20 June 2006

Dome OpenSceneGraph

I've abandoned vertex shaders for a while, and have hacked one of the OpenSceneGraph examples to do dome correction. This uses a 6 camera frustum looking at the scene. The output of which is then stitched and mapped onto a sphere as a texture. In our case we need the view from the inside of the sphere rather than the external surface.

Saved Image

A vertex shader is being used to the texture mapping - and on a 1.83Ghz Macbook Pro it can manage 60fps with a texture size of 512.

This is quite a moment: I have been trying to achieve this in my spare time since September 05. This means we have a standard dome-corrected platform for 3D models, Geospatial data, streamed video, Meteorological data. I've used large APIs before (namely QuickTime) - OpenSceneGraph is actually a pleasure to use. It has high level features that mean you can get things working quickly - but doesn't punish you later when you need to drill down for some reason.