"Andreas Zehender" <zeh### [at] kdeorg> schrieb im Newsbeitrag
news:3be7002e@news.povray.org...
> Jan Walzer wrote:
>
> > Are lookuptables still needed today for these usages ?
> > AFAIK first-person-shooters and thelike are using the FPU of the current
> > processors, so there shouldn't be the need to "accelerate" the program
> > this way....
> > (of course, these games are using mostly a perspective camera)
>
> I think so. You have much more vertexes than first person shooters in a
> modeler. Rendering the wireframe of the chess2.pov example takes half a
> second on my TNT 2 and a 433 celeron with a perspective camera.
> And the perspective camera uses only simple transformations.
>
> I think calling trigonometrical functions for each vertex would be far too
> slow (didn't tested it yet)


I think there are other optimizations to go before using tables ...
I can't really believe that the FPUs are still SOOOOO much slower ...
Consider, that for a modeller, you'll need a very high accuracy, and so you
need very big tables ...
Also I'm sure, you won't use Integer(or Fixpoint)-Maths ...
So you'll have to transfer your numbers from FPU to memory, and back often
enough ...
This won't speed up your program very much ...

I for myself, would leave this option open, as one of the last ways to speed
up, if it's still to slow ... (or make it optional)

You surely have already thought about backface culling and thelike, haven't
you ?


--
Jan Walzer <jan### [at] lzernet>

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