how do you make an object glow?

Jack · January 15, 2010, 11:39:09 PM

im wondering how do you make a certain material glow and glow as in cast light off onto the surrounding scene?

old_blaggard · January 15, 2010, 11:40:10 PM

Use a default shader with luminosity settings.

Jack · January 15, 2010, 11:41:34 PM

yes i have tried that but the object glows but it doesn't interact or cast light onto surrounding structures

Oshyan · January 16, 2010, 03:31:30 AM

Crank up the Luminosity value... a lot.

- Oshyan

FrankB · January 16, 2010, 04:23:27 AM

BUT, Jack, you should understand that you don't get any real glow this way. Cranking up luminosity a lot may illuminate the immediate surroundings somewhat, if you use high GI sample quality, 4 and above. The object is not really emmitting light, though. What you'll see on the surroundings is a GI effect.
The effect that you are looking for (probably) is a glow that surrounds the object as well. But for this, there must be something to illuminate, such as dust particles or smoke. As long as there's nothing to be lightened in the air around your object, you won't get this kind of glow effect.

Henry Blewer · January 16, 2010, 08:49:50 AM

I would turn off the ray traced shadows for the objects. Then add a light source inside the object. It would be nice if shadows could be turned off for specific objects (can it? I am rendering and can't run another Terragen 2).

Frank may have a good idea. A very low density cloud might do the trick to simulate a glow effect.

Oshyan · January 16, 2010, 10:16:47 PM

Sure the object is *emitting light* when you're using luminosity and GI... Frank, I don't really understand what you mean.

And with the glow effect turned on in the renderer, a luminous object will also glow...

- Oshyan

Cyber-Angel · January 16, 2010, 10:56:27 PM

I think that what is been asked for is a glow that affects the surrounding environment, in the way a candle or fire would do. In other words a glow that is brighter towards its source then falls off proportionally with distance.

That would be my interpretation of what is been asked for.

Regards to you.

Cyber-Angel

TheBlackHole · January 16, 2010, 11:30:57 PM

What kind of object do you mean? If it's something other than solid, it can probably be done entirely within TG2.

Jack · January 17, 2010, 02:13:37 AM

hey guys thanks for the replies I am meaning something like this its a small test render done in vue with GR
see how the light bounces of the surrounding objects and ground can terragens luminosity tab do this?

TheBlackHole · January 17, 2010, 02:18:12 AM

I know in your render it's a glowing panel, but if you need light coming out of the inside of, say, a box, stick a light source in there with a large radius and soft shadows. I haven't tried it, but I think it might work.

jo · January 17, 2010, 02:31:41 AM

Hi,

Yes, it does work, pretty much the same as Vue I guess. Here is a quick example done using some spheres, one of which has the Luminosity value set to 1 in its Default shader. This is using the default GI settings. You can see it's illuminating the ground and the other spheres. It only took a minute to set this up.

Regards,

Jo

jo · January 17, 2010, 03:02:21 AM

Slightly more interesting...

Jack · January 17, 2010, 03:27:23 AM

very cool!!!
I must admit I have not tried this since the old 1.6 terragen............. lol
! and i didnt seem to work back then so great news here^^

Henry Blewer · January 17, 2010, 08:30:49 AM

I dug out one of my Blender books to read at work. They have a post compositing method which may work. It will take quite a Blender node set up to get it to work right. Essentially it uses the objects as a mask and a luminance source. Blur is applied and a circular mask is applied to restrict the glow area. I doubt I can get it work right. I do not have any experience using EXR image z depth.