POV-Ray : Newsgroups : povray.advanced-users : speed details Server Time
29 Jul 2024 16:26:27 EDT (-0400)
  speed details (Message 1 to 5 of 5)  
From: Wlodzimierz ABX Skiba
Subject: speed details
Date: 12 Mar 2001 10:56:23
Message: <3aacf1a7@news.povray.org>
I just wonder how keyword "open" in cylinder statement influences speed of
rendering - I have a lot of cylinders with not visible bases - is it worth to
add some extra characters to type "open" and increase file size and speed of
parsing and typing :-) to achive a little faster rendering ?

ABX


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From: Bob H 
Subject: Re: speed details
Date: 12 Mar 2001 22:36:16
Message: <3aad95b0$1@news.povray.org>
Actually could potentially increase render times.
If reflection is used for example the inner parts of the cylinder would get
checked instead of remaining outside.  Same for radiosity.  Any gaps to the
insides of the cylinders would be seen by POV even though unseen by the
camera directly.

Bob H.


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From: Peter Popov
Subject: Re: speed details
Date: 13 Mar 2001 17:49:01
Message: <iqeratc4a4n8fjrm932r57duk85301pdqi@4ax.com>
On Mon, 12 Mar 2001 16:56:06 +0100, "Wlodzimierz ABX Skiba"
<abx### [at] abxartpl> wrote:

>I just wonder how keyword "open" in cylinder statement influences speed of
>rendering - I have a lot of cylinders with not visible bases - is it worth to
>add some extra characters to type "open" and increase file size and speed of
>parsing and typing :-) to achive a little faster rendering ?

Do some testing :) It should be a little bit faster because the caps
are ray-shape-intersection-tested separately (if the cylinder is not
open).


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg


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From: Tekno Frannansa
Subject: Re: speed details
Date: 14 Mar 2001 18:01:56
Message: <3aaff864@news.povray.org>
> Do some testing :) It should be a little bit faster because the caps
> are ray-shape-intersection-tested separately (if the cylinder is not
> open).

But surely in the end of the cylinder is limited by a plane, which has to be
checked in either case (as the cylinder isn't infinitely long)? And if you
can't see the ends then it shouldn't do any more processing beyond that.

Still, it can't hurt to try :)

--
Tek
http://www.evilsuperbrain.com


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From: John VanSickle
Subject: Re: speed details
Date: 16 Mar 2001 02:34:12
Message: <3AB1C1F3.3482C2E9@hotmail.com>
Tekno Frannansa wrote:
> 
> > Do some testing :) It should be a little bit faster because the caps
> > are ray-shape-intersection-tested separately (if the cylinder is not
> > open).
> 
> But surely in the end of the cylinder is limited by a plane, which has
> to be checked in either case (as the cylinder isn't infinitely long)?
> And if you can't see the ends then it shouldn't do any more processing
> beyond that.
> 
> Still, it can't hurt to try :)

The plane clipping test is different from a ray-plane intersection test.

Due to the automatic bounding of objects, there will probably be little
gain; if the bound check shows a miss, the whole cylinder is skipped,
and therefore the ends aren't checked anyway.

Regards,
John


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