I've been generating some movies of moving human heads for my Psychology
research.

Some examples are:

http://cognitrn.psych.indiana.edu/busey/forZyg/nogridunstretched.mov

and

http://cognitrn.psych.indiana.edu/busey/forZyg/nogridstretched.mov

(If you view them, try to figure out what is different between the two
heads. Hint: one is
_not_ moving faster or covering more anglular extent).

The problem with POV comes when I add grids:

http://cognitrn.psych.indiana.edu/busey/forZyg/twistedgridunstretched.mov

and
http://cognitrn.psych.indiana.edu/busey/forZyg/twistedgridstretched.mov

I use CSG subtractions to add the grids on the faces (which are just
thin planes).

The problem with the grids is that I go from 7 minutes to render one
frame about 2 1/2 hours. This is on a sun workstation with version 3.05
(or something less than 3.1).

I suspect that the problem has something to do with I-Stack overflows.
I've appended the results below. It would be a big help to my research
program if anyone had hints about how to solve this problem. I can post
the relatively simple code if necessary.

Thanks so much

Tom Busey
Associate Professor
Department of Psychology and Program in Cognitive Science
Indiana University
Bloomington, IN

bus### [at] indianaedu


Here is the output:

050.pov Statistics (Partial Image Rendered), Resolution 2867 x 2150
----------------------------------------------------------------------------

Pixels:         1025640   Samples:         1284240   Smpls/Pxl: 1.25
Rays:           1284240   Saved:                 0   Max Level: 1/5
----------------------------------------------------------------------------

Ray->Shape Intersection          Tests       Succeeded  Percentage
----------------------------------------------------------------------------

Box                          126484272        33198291     26.25
CSG Intersection               3513452         1604679     45.67
Mesh                           1756726          354797     20.20
Sphere                         3513452         1636191     46.57
Bounding Box                  40422587        11333615     28.04
----------------------------------------------------------------------------

Calls to Noise:                  0   Calls to DNoise:             10
----------------------------------------------------------------------------

Shadow Ray Tests:           472486   Succeeded:                  584
I-Stack overflows:        11333814
----------------------------------------------------------------------------

Smallest Alloc:                 11 bytes   Largest:          6815752
Peak memory used:         18080275 bytes
----------------------------------------------------------------------------

Time For Parse:    0 hours  2 minutes  33.0 seconds (153 seconds)
Time For Trace:    2 hours  4 minutes  46.0 seconds (7486 seconds)
    Total Time:    2 hours  7 minutes  19.0 seconds (7639 seconds)

Post a reply to this message

Tom Busey wrote:
> 
> [...]
> 
> I use CSG subtractions to add the grids on the faces (which are just
> thin planes).
> 
> The problem with the grids is that I go from 7 minutes to render one
> frame about 2 1/2 hours. This is on a sun workstation with version 3.05
> (or something less than 3.1).
> 
> I suspect that the problem has something to do with I-Stack overflows.
> I've appended the results below. It would be a big help to my research
> program if anyone had hints about how to solve this problem. I can post
> the relatively simple code if necessary.
> 

Because of the I_Stack overflows i persume you are using quite a complex
CSG construction wich can slow things down a lot.  Since i don't have
quicktime installed, i wasn't able to view the movies so i can't say for
sure. Some pictures or a mpeg would help (you can post it in one of the
binaries groups).  

Since this seems no unix-specific question, it would be better to ask in
povray.newusers or povray.advanced-users, feel free to set a followup. 

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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