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.
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