Tried to search for this to no avail...

I'm trying to figure out how to make an object emit it's own light. For 
example, if you have a sphere of which one side is red and the other 
green and you have it in a box with no other lights, one side of the box 
will look red, the other green, because of the glowing object.

I've seen pictures of this, but I don't know the basics involved in 
getting it done. I think it has something to do with "ambient" and 
"diffuse" in "finish", but I'm not sure of the details...

Thanks!

Arlo

Post a reply to this message

"Arlo J" <ajginger_SPAMNOT_@look.ca> wrote in message 
news:413135e6$1@news.povray.org...
>
> I'm trying to figure out how to make an object emit it's own light. For 
> example, if you have a sphere of which one side is red and the other green 
> and you have it in a box with no other lights, one side of the box will 
> look red, the other green, because of the glowing object.
>
> I've seen pictures of this, but I don't know the basics involved in 
> getting it done. I think it has something to do with "ambient" and 
> "diffuse" in "finish", but I'm not sure of the details...

You were on the right path then, just asking in the wrong place here, since 
povray.general or povray.newusers would be best.

Only thing to do is have radiosity{} in the global_settings{} and use a 
highly ambient and/or diffuse finish (numbers greater than one are 
possible). There's a recommendation for 'ambient' to be zero when using 
radiosity. However, that is not required. To make the glowing object 
actually glow itself you'll need its ambient to be greater than 0 (e.g. 1) 
anyway. Check it using ambient 10 and you should see plenty of faked light 
on surroundings.

All scene elements interact so their finishes will also matter. In this 
case, the box around the glowing sphere will need a good amount of diffuse 
(not ambient) to show the "emitted" glow. A radiosity keyword 'brightness' 
could also help, default being 1 and higher numbers increase the affect. 
Speaking of which, the default 'gray_threshold' of 0 in radiosity is already 
allowing full color-bleed so don't increase it (more gray=less color, 
obviously).

Post a reply to this message

Hughes, B. wrote:

> You were on the right path then, just asking in the wrong place here, since 
> povray.general or povray.newusers would be best.

Thanks! You're right.. I clicked on the wrong group in my Usenet 
program. Bit of a cold, you see. ;)

Thanks for the tips!

Arlo

Post a reply to this message