The Experiments...
So, I have set-up a dome to play with, using a £6 Ikea lamp. This works ok for what it is. It helped me understand the role of fisheye/wide angle lenses in the projection phase of domes. That is, they are not absolutely necessary. At present, the projector is about 1 1/2 metres from the dome. If this were scaled to a full size dome, then a 10m pit would need to be dug to accommodate the projector. Hence the need for wide-angle lenses. The other reason is the wide depth of field. With a small dome the distance between the projector and the edge of the dome vs the distance between the projector and zenith of the dome is negligible - but with a full size dome this becomes an issue - having a wide-angle/fisheye means the projector can keep the projected image in focus across the dome.
I have been doing some experimentation with Blender and Yafray. Hidden in the documentation for Yafray is a camera type of "lightprobe" - this produces a spherical image:
...Unfortunately, it turns out to be a 360 degree view, rather than 180, but its a start. I am now looking into using Blender with POVRay - which is know to produce 180 degree spherical output.
Following up on a post by David McConville on FullDome.org - I have been looking at "Fisheye Quake". This had gone a bit stale - it was a Windows only hack. I found the source code for the hack, and coupled with the fact that Quake 3 was GPL'd a few weeks ago, I'm confident that we can get this going in the dome. The interesting part of this is that "modding" applications for Quake 3 are quite common, potentially opening up the quake engine to Artistic/Visualisation activities...
