[Radiance-general] Optimizing Radiance for cluster rendering

[Lars O. Grobe]

Hi,

I never compiled using icc, but on the cluster topic I have some comments.

First, I would make sure that you use frozen octrees. Compiling the same
scene from scratch on each node does not make sense.

As you say, copying the scene to the computing nodes before running the
processes does not make much difference, though that may depend on the
cluster archicecture you are building up on. I had an Openmosix cluster,
where I could start all processes on one node, which were then
automatically "migrated away" to other available nodes (no shared
memory, each process had a full set of scene data in that case). As
rpict/rtrace processes typically load the scene data once before
spawning sub-processes (by copying the process data), there is not
really more io involved then copying the data separately before starting
the processes. If you start processes over ssh, sharing data by nfs
mounts, it may help to have some delays so that not all nodes try to
fetch the data at the same moment.

My guess is that the one critical point in sharing data is access to
ambient cache and image data. You are probably aware of this.

Cheers, Lars.