Warp <war### [at] tagpovrayorg> wrote:
> Tom York <alp### [at] zubenelgenubi34spcom> wrote:
> > I got about 1fps
> > at 160x128 on a complex scene involving complex meshes, refraction,
> > transparency, image maps and so on
>
>   It'd be interesting to know how much it speeds up if you use the
> quality parameter (+q) to turn off the slowest features.
>
> --
>                                                           - Warp

I did some more precise testing today. The scene involves a 180 degree pan
that starts with the camera point at several complicated (self-shadowing)
mesh objects. The pan then crosses two largely empty regions (just a
procedural background texture) with a few meshes appearing here and there,
and then finally ends up pointing at a large object made of meshes, and
torii/cylinders/other finite solid primitives. There is a lot of refraction
going on at the end, although the refracting surface is just a simple cone.
As expected, the frame rate is quite variable.

I used 100 cameras and let the animation run over 600 frames at 160x128. I
also turned on hyperthreading in the PC's BIOS settings, since I was a bit
curious to see if anything would happen (I disabled it a long time ago
since some software didn't like it). It may have done absolutely nothing
(can't be sure as I wasn't careful with the timing yesterday).

The scene data is about 16 million tokens worth, plus some large (2048x2048,
24 bit) image maps, and takes about 30-40 seconds to parse. Initially,
max_trace_level was set to 20 (what was used in the original scene) and the
+Q quality setting was left at default (full quality). That's the "base"
figure:

1) Base: 1.7-1.8 fps
2) With +Q2: 2.8 fps
3) With max_trace_level 5: 1.7-1.8 fps
4) With max_trace_level 2: 1.8 fps
5) With max_trace_level 1: 1.8-1.9 fps

The fps values quoted above came from the average reported in the status bar
after 600 frames. The average was reasonably stable after 600 frames,
although it sometimes varied enough that I've stated a range of values
where necessary.

The aspects of +Q2 that had the most effect on speed were presumably the
elimination of shadows and refractive surfaces. max_trace_level 1
eliminates the refraction, I guess, so perhaps that leaves shadows as the
most time-consuming feature. On the other hand, the refraction is only
present at the end, but there are shadowed objects through most of the
animation. Visually, at 160x128 there is not much difference between +Q2
and full quality; the absence of refraction is the most noticable effect.

Tom

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