[Radiance-general] Instances + octrees

[Lars O. Grobe]

Hi list!

First, I am still using v3.5 - I have a Mac and no X-sources, so it's 
hard to compile Head.

To improve the performance during rendering a very large model, I 
atomized it into LOTS of small parts. These are assembled by replmarks, 
using octrees generated with oconv -f. I thought this was the most 
efficient solution, and I want to save memory. This leads to a model 
which is assembled from hundreds of octrees (instances).

Now, after importing one more (and big) part into the model, I am not 
able to oconv the file which is to assemble all these instances any 
more. Oconv is running without end, I stop it when it takes about 300 
MB memory. When I use xform to insert my elements (the same model, just 
replaced the -i by -x and *.oct by *.rad in the replmarks command 
line), not instances, everything works fine (except of a very large 
octree).

I heard about some "overlapping octree" problems, however, I never 
understood how they appear. May this be one such problem? Actually, the 
geometry is not overlapping, but the small octrees bounding boxes 
certainly are (as they are all cubes, right?). What did you experience 
with such instanced models?

Is the oconv tool in the 3.5 buggy? Any known bugs like that?

Is it my error (should I check my scripts ten more times ;-) ?

I really would like to keep using octree-instances, as the model is 
growing quite fast at the moment, and I won't be able to finally render 
it on my machine without instances. So I am very interested in why this 
problem appears and how to resolve it.

TIA+CU, Lars.
--
Lars O. Grobe
grobe at gmx.net