I am trying to figure out a way to speed up rendering of a complicated scene
that contains two heavily-detailed and textured objects, and I think I've
come up with a solution but have a question for the experts.

My scene consists of two major objects, "A" and "B". "A" is surrounded by
"B", so the light source for the scene causes "B" to cast shadows on "A".
"B" is in the shape of a hollow cylinder, and from the vantage point of the
camera "A" obscures parts of "B", but not vice-versa.

On one computer, I turn PNG alpha output on and have declared object "B" as
"no_image" and "no_reflection" so that when rendered all the camera sees is
object "A" + the shadows cast onto it by object "B".

On a second computer I've done just the opposite: I again turn PNG alpha
output on but this time I have declared object "A" as "no_image" and
"no_reflection" so that when rendered all the camera sees is object "B" +
the shadows cast onto it by object "A".

I take the two images and layer them together in Photoshop, and voila! "A"
seems to be inside of "B", shadows and all, but the net time it took to
render the scene is cut by more than half.

Here's my question: Should I be able to speed up things even more by
deleting the texture declarations from the object that is "no_image" and
"no_reflection"? The thing is, I've tried doing that and timed the output,
but my results have been inconclusive. It *seems* to be slightly faster, but
not by much. So, does declaring an object to be "no_image" and
"no_reflection" cause texture and material calculations to be skipped, or
not?

thanks.

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In article <40295e27$1@news.povray.org>,
 "Scott Gammans" <dee### [at] yahoocom> wrote:

> Here's my question: Should I be able to speed up things even more by
> deleting the texture declarations from the object that is "no_image" and
> "no_reflection"? The thing is, I've tried doing that and timed the output,
> but my results have been inconclusive. It *seems* to be slightly faster, but
> not by much. So, does declaring an object to be "no_image" and
> "no_reflection" cause texture and material calculations to be skipped, or
> not?

The object isn't even considered if one of those flags is set. No 
intersection testing is done, let alone texture calculation (which would 
require the intersection info in the first place). You would speed 
things up very slightly by removing the textures, but only by the time 
required to parse, build, and dismantle those data structures: too 
little time to accurately measure for the vast majority of cases.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/

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