I'm trying to duplicate a complicated floor pattern I see in a photo. It's
texture has texture_map's couple of layers deep.

I have one scene in an animation that is rendering unusually slow compared
to some of the others.  In considering the suspects I'm wondering if it's
the floor tile!

Q: do multi-layered patterned textures slow up render speed?
 
Any tips on how to speed it up: 
        is it better stick to patterned pigments and do without "normal" in the
texture?
        are there any problems with the way in which you define a pattern--is there
a trick to defining it all in one gulp?

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Greg M. Johnson nous apporta ses lumieres en ce 21-01-2007 08:03:
> I'm trying to duplicate a complicated floor pattern I see in a photo. It's
> texture has texture_map's couple of layers deep.

> I have one scene in an animation that is rendering unusually slow compared
> to some of the others.  In considering the suspects I'm wondering if it's
> the floor tile!

> Q: do multi-layered patterned textures slow up render speed?

> Any tips on how to speed it up: 
>         is it better stick to patterned pigments and do without "normal" in the
> texture?
>         are there any problems with the way in which you define a pattern--is there
> a trick to defining it all in one gulp?

Layered textures are slower than simple oned as each layer have to be evaluated 
(but only if behind a transparent part of the preceding one(s)). So, yess, 
layered textures do slow you down, BUT there are many other things in most 
scenes that can have much more effect.
Do you have refflections? What is been reflected?
Do you have transparent or partly transparent object? With an ior? Using 
dispersion? Those will slow you down.
In almost all scenes, normal have only a negligible effect on speed, exeption: 
in a radiosity scene with "normals on" set in the radiosity block = big slowdown.
Look at the geometrys in your scene, do you use many difference and 
intersections? With LOTS of small parts removed? This is a common source of 
slowdowns.
A trick is to turn on the histogram feature and look at the result. Bright parts 
= slow parts. Use the "+htn" switch on the command line to turn on and set the 
output to PNG. Using that switch, there is a 1 to 1 relation between the final 
image and the histogram output.
On the windows version, there is a "command line" box next to the resolution 
selector.

Some tips:
Take a look at the scene statistics, do you have any entries with low percents?
Try removing objects that you don't see. If some object is only seen in 
reflections and the reflection is small or distorted, replace it with a mockup 
that have about the same apearance.
Do you have differences where you remove LOTS of small parts? When evaluating 
such an object, you need to check for ALL the removed parts for each pixel: all 
the bounding box overlap! It may be faster to put those small removed parts in a 
merge. That way, all components are treated as a single object having only one 
common bounding box.
Do you use any sphere_sweep? Are they long and thin? With broad curves? If so, 
try splitting them into a collection of shorter sweeps.

-- 
Alain
-------------------------------------------------
WARNING: the crumsumpten of alcohol may Mack you tink you kan tpye reel gode

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Alain <ele### [at] netscapenet> wrote:
> Layered textures are slower than simple oned as each layer have to be evaluated 
> (but only if behind a transparent part of the preceding one(s)). So, yess, 
> layered textures do slow you down

  If I'm not completely mistaken, each individual texture in a layered
texture is evaluated fully (in the same way as in an average texture map).
This means that, for example, if you have 10 textures layered, each one
reflective, 10 reflection rays will be shot for each evaluation of the
layered texture.

  If you have this situation, try turning off reflections for the textures
which really don't need them.

-- 
                                                          - Warp

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Warp nous apporta ses lumieres en ce 21-01-2007 10:13:
> Alain <ele### [at] netscapenet> wrote:
>> Layered textures are slower than simple oned as each layer have to be evaluated 
>> (but only if behind a transparent part of the preceding one(s)). So, yess, 
>> layered textures do slow you down

>   If I'm not completely mistaken, each individual texture in a layered
> texture is evaluated fully (in the same way as in an average texture map).
> This means that, for example, if you have 10 textures layered, each one
> reflective, 10 reflection rays will be shot for each evaluation of the
> layered texture.

>   If you have this situation, try turning off reflections for the textures
> which really don't need them.

OK. It's beter to have only one with reflection (most importent), phong and 
specular.

-- 
Alain
-------------------------------------------------
Don't cry because it is over, smile because it happened.

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Alain <ele### [at] netscapenet> wrote:
> OK. It's beter to have only one with reflection (most importent), phong and 
> specular.

  But then, that may change radically the looks of the texture, so it
might not always be an acceptable solution.

-- 
                                                          - Warp

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About five times now, I've presumed I had discovered the cause of the
slowup:  supers, multi-layered textures with reflection,  very low-angle
view of a 5000-unit box with layered pigments, etc. Each time I eliminate
the bad feature but still there is no change in the effect. I have a 4320
frame animation, and the scene at frames 200 to 600 takes longer than
overnight to render, whereas the remaining 3600 flash on by in a "work
day". (This is just the 160x120 preview.)  It also seems that the math
ain't right-- these slow hundreds go by much more slowly than the forumla
of (secs/frame I observe before I go to bed) x (number of frames).   I
suppose the last thing to delete is the human character (a very complex
blob)-- I've got a different include file for this one blob than that
present in all the other scenes, but no idea why this one should slow
things down.

I would be tempted to think it were a sleep setting on my KDE/ Knoppix 5.01
box, but I remember seeing the same slow-up with the older version on my
kubuntu box with the same chip speed.




Warp <war### [at] tagpovrayorg> wrote:
> Alain <ele### [at] netscapenet> wrote:
> > OK. It's beter to have only one with reflection (most importent), phong and
> > specular.
>
>   But then, that may change radically the looks of the texture, so it
> might not always be an acceptable solution.
>
> --
>                                                           - Warp

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