Chris Huff <chr### [at] maccom> wrote:
> In article <39bf701f@news.povray.org>, Geoff Wedig 
> <wed### [at] darwinepbicwruedu> wrote:

>> Trust me, I understand.  I'm not adverse to high parse times, though. 
>>  Some of my code takes ~2 hours to parse, then another 2-3 to 
>> allocate memory/bounding boxes, etc.  *then* I get to render.  It 
>> gets about three lines in 12 hours.  I run it over night/while I'm at 
>> work (which means I get to reparse each night.  Ghods I wish there 
>> was a 'pickle' function for parsed POV files!).  It might be done by 
>> Christmas.

> "Pickle" function?

Sorry, python term.  Pickling an object is taking it and turning it into a
file. Basically, I'm thinking of something like a memory map of the object
space saved to disk.  This would require no parsing, basically, because the
memory map could then be reloaded and just placed in memory.

> You could have it output the objects after calculating them, so the 
> calculations don't have to be done again. The file sizes would probably 
> be quite big, though.

*very* big.  The current image is >200,000 objects, most with their own
textures (based on an algorithm).  I don't think that's practical.

> You might also get a speedup by turning vista buffering off...doing that 
> will slow down rendering, but the 2-3 hours you save by not calculating 
> them might make it worth it. It will also cut your memory usage down a 
> bit.

Unfortunately, many of the objects are small, so removing vista buffers and
bounding boxes would be fatal (I think.  I must admit I don't know for sure)

> If not all of the objects are visible and they aren't reflective or 
> transparent, consider dropping some of them from the scene.

already done.  There were a few that cast particular shadows that I removed
after those shadows were rendered (because I'm doing this incrementally, I
can do that)

Most of the problem is related to disk thrashing, I must admit.  I have 256
MB, and after the parse it never goes to disk, but while it's parsing, the
disk goes non-stop.  It's pretty ugly.

To be honest, I could reduce a lot of the work done in the macros given the
new features added in Megapov.  I just haven't had time so far to fiddle
with the code.

> Instead of writing a separate program, you could do what I did with my 
> particle system, and turn it into a POV patch. If you want to get points 
> on an object, you have all the necessary tools right there.

I didn't have the time to learn the POV code.  Secondly, I really wasn't
certain that doing it in pov was the best thing (from an efficiency
standpoint) and finally, I could run my simulation on a different computer,
so it could run while I rendered other stuff.

I haven't looked at your particle system patch yet, but I plan to the next
time I have a reason to use it.

Geoff

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