POV-Ray : Documentation : 1.4.1.1 How do I make a visible light source?
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1.4.1 Language Tips and tricks to achieve useful things   1.4.1.2 How do I make bright objects?

1.4.1.1 How do I make a visible light source?

"How do I make a visible light source?" or: "Although I put the camera just in front of my light source, I cannot see anything. What am I doing wrong?"

A light source in POV-Ray is only a concept. When you add a light source to the scene, you are actually saying to POV-Ray "hey, there is light coming from this point". As the name says, it is a light source, not a physical light (like a light bulb or a bright spot like a star). POV-Ray does not add anything to that place where the light is coming, ie. there is nothing there, only empty space. It is just a kind of mathematical point POV-Ray uses to make shading calculations.

To make the light source visible, you have to put something there. There is a looks_like keyword in the light_source block which allows to easily attach an object to the light source. This object implicitly does not cast any shadows. You can make something like this:

light_source
{ <0,0,0> color 1
  looks_like
  { sphere
    { <0,0,0>,0.1
      color { rgb 1 }
      finish { ambient 1 }
    }
  }
  translate <10,20,30>
}

It is a good idea to define both things, the light source and the looks_like object, at the origin, and then translate them to their right place.

Note also the 'finish { ambient 1 }' which makes the sphere to apparently glow (see also the next question).

You can also get visible light sources using other techniques: Media, lens flare (available as 3rd party include file), glow patch, etc.

1.4.1 Language Tips and tricks to achieve useful things   1.4.1.2 How do I make bright objects?


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