POV-Ray : Newsgroups : povray.binaries.animations : Trace and its flexibility (considering Particles) Server Time
20 Jul 2024 03:21:09 EDT (-0400)
  Trace and its flexibility (considering Particles) (Message 1 to 5 of 5)  
From: Tim Nikias
Subject: Trace and its flexibility (considering Particles)
Date: 5 Dec 2001 19:16:17
Message: <3C0EB866.8F8A2BD4@gmx.de>
Hi Ho there people!

I heard a lot about the trace-function, but, since I didn't download a
beta
of 3.5 yet, I don't know, how it actually works and what it's suitable
to
do.

I've heard that it can only check if two objects intersect, and that
certain variables can be used to check the actual intersection point.

Is there a function, with which you can take a position, shoot a ray
into a given direction, and have POV-Ray return the distance until
the ray hits an object?

Or have a gotten something completely mixed up?

It's just that I'm wondering, how difficult I/O really is with
particles,
and since I've begun thinking about creating such a system some day,
I'd like to think in correct terms, instead of believing something
utterly
useless...

Tim


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From: Mike Williams
Subject: Re: Trace and its flexibility (considering Particles)
Date: 5 Dec 2001 21:40:53
Message: <UW4yKDAmotD8EwCG@econym.demon.co.uk>
Wasn't it Tim Nikias who wrote:
>Hi Ho there people!
>
>I heard a lot about the trace-function, but, since I didn't download a
>beta
>of 3.5 yet, I don't know, how it actually works and what it's suitable
>to
>do.
>
>I've heard that it can only check if two objects intersect, and that
>certain variables can be used to check the actual intersection point.
>
>Is there a function, with which you can take a position, shoot a ray
>into a given direction, and have POV-Ray return the distance until
>the ray hits an object?
>
>Or have a gotten something completely mixed up?

You are a bit mixed up. Trace does just what you want.

Trace shoots a ray in a given direction and returns the point where the
ray intersects the surface and the direction of the normal at that
point. (If you really want the distance you would then use vlength()).

-- 
Mike Williams
Gentleman of Leisure


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From: Nekar Xenos
Subject: Re: Trace and its flexibility (considering Particles)
Date: 6 Dec 2001 01:10:38
Message: <3c0f0bde@news.povray.org>
"Mike Williams" <mik### [at] nospamplease> wrote in message
news:UW4### [at] econymdemoncouk...

> and the direction of the normal at that
> point.

This is the part I don't understand yet. How can I use this direction of the
normal to rotate an object according to this direction. The sample uses a
cylinder, which is easy. But I need to use rotate <x,y,z>  for my object (the
logo on my car).

--
- Nekar

http://nekar_xenos.tripod.com/metanoia/



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From: Christoph Hormann
Subject: Re: Trace and its flexibility (considering Particles)
Date: 6 Dec 2001 02:58:06
Message: <3C0F253E.C9A87F65@gmx.de>
Nekar Xenos wrote:
> 
> This is the part I don't understand yet. How can I use this direction of the
> normal to rotate an object according to this direction. The sample uses a
> cylinder, which is easy. But I need to use rotate <x,y,z>  for my object (the
> logo on my car).

See 'Reorient_Trans()' in transforms.inc

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/


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From: Nekar Xenos
Subject: Re: Trace and its flexibility (considering Particles)
Date: 6 Dec 2001 05:53:55
Message: <3c0f4e43@news.povray.org>
Thanks, Christoph. I'll check it out.

--
- Nekar

http://nekar_xenos.tripod.com/metanoia/

"Christoph Hormann" <chr### [at] gmxde> wrote in message
news:3C0F253E.C9A87F65@gmx.de...
>
>
> Nekar Xenos wrote:
> >
> > This is the part I don't understand yet. How can I use this direction of the
> > normal to rotate an object according to this direction. The sample uses a
> > cylinder, which is easy. But I need to use rotate <x,y,z>  for my object
(the
> > logo on my car).
>
> See 'Reorient_Trans()' in transforms.inc
>
> Christoph
>
> --
> Christoph Hormann <chr### [at] gmxde>
> IsoWood include, radiosity tutorial, TransSkin and other
> things on: http://www.schunter.etc.tu-bs.de/~chris/


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