Hi,

I've got a problem that I think might be a bug but am not sure. I'm trying
to model a laserbeam. To do this I call a cylinder of the required colour
then assign a cylindrical spotlight to this cylinder.....now this works fine
in that the beam looks like a beam and radiates light like I desire.
However, I get what appears to be an artifact, in that a new cylinder seems
to appear at the origin (o,o,o) going straight up but not acting like a
light source........I've checked the .pov file and there is no cylinder
called for at that location, it only appears in the rendered image. I have
three laserbeams in the scene that I call but only one artifact appears and
it appears no matter which laserbeam(s) I call. Can anyone give me some
advice to eliminated this problem or even tell me a better way to simulate a
laserbeam

Thanks

Owain Knight

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Perhaps you could provide a piece of the offending code.
It's difficut to diagnose such problems without knowing
how the source is implemented. Sometimes it is the simplest
things that cause a problem like yours.

Ken Tyler

Leviathon wrote:

> Hi,
>
> I've got a problem that I think might be a bug but am not sure. I'm trying
> to model a laserbeam. To do this I call a cylinder of the required colour
> then assign a cylindrical spotlight to this cylinder.....now this works fine
> in that the beam looks like a beam and radiates light like I desire.
> However, I get what appears to be an artifact, in that a new cylinder seems
> to appear at the origin (o,o,o) going straight up but not acting like a
> light source........I've checked the .pov file and there is no cylinder
> called for at that location, it only appears in the rendered image. I have
> three laserbeams in the scene that I call but only one artifact appears and
> it appears no matter which laserbeam(s) I call. Can anyone give me some
> advice to eliminated this problem or even tell me a better way to simulate a
> laserbeam
>
> Thanks
>
> Owain Knight

Post a reply to this message

Make sure your not on an axis exactly (camera location and look_at both 
aligned along x, y, or z), check for possible reflective enclosure as well. 
Could be any number of things though, especially if any CSG was used.

For a laser "beam" itself, no housing, the cylinder spotlight alone makes an 
okay laser light. Just use a high tightness and large radius, adjusting 
falloff for the glow needed. Turning up the light color above 1 doesn't hurt 
either. Sparse media (atmosphere in 3.0*) scattering with lower samples for a 
dusty look. Guess you must already have some sort of "air" already or you 
wouldn't be seeing that cylinder spotlight in the first place, unless of 
course you are using the light and cylinder object as a single entity and 
relying upon specular highlighting.
Like Ken said, best if you posted the script in question somewhere.

Message <365587e5.0@news.povray.org>, Leviathon  typed...
>
>Hi,
>
>I've got a problem that I think might be a bug but am not sure. I'm trying
>to model a laserbeam. To do this I call a cylinder of the required colour
>then assign a cylindrical spotlight to this cylinder.....now this works fine
>in that the beam looks like a beam and radiates light like I desire.
>However, I get what appears to be an artifact, in that a new cylinder seems
>to appear at the origin (o,o,o) going straight up but not acting like a
>light source........I've checked the .pov file and there is no cylinder
>called for at that location, it only appears in the rendered image. I have
>three laserbeams in the scene that I call but only one artifact appears and
>it appears no matter which laserbeam(s) I call. Can anyone give me some
>advice to eliminated this problem or even tell me a better way to simulate a
>laserbeam
>
>Thanks
>
>Owain Knight
>
>

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/POVring.html
=Bob

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