Emit light from imported object

Started by lookdev, December 05, 2018, 10:59:06 AM

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lookdev

How do I emit light from an imported obj? so light is emitted from the whole shape of the obj

cyphyr

Check out the internal network of the object and look for the the "default shader".
There you can raise the luminosity value.
Remember that the slider stops at 1 but you can type in values as high as you like.
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lookdev

#2
I did, but the object (in this case a sphere) doesn't reflect light on anything else (surrounding objects or landscape), it just becomes brighter and brighter (like more white). See attached, the first is a sphere, the second is a light source from lighting tab.
How do I get the sphere to care more about the others around it?

Hannes

No idea, why this doesn't work for you.
I imported a sphere, positioned it close to the ground, used a bright white diffuse color and set the luminosity to 1.

For some reason this doesn't really work with the internal sphere object, but you wanted an imported object to reflect light, right?

lookdev

I've actually used the internal sphere assuming it would work for imported. I will check for an imported.

KlausK

hi, these are all imported objects. It works, but not always as expected.
Some things I found making it kind of unpredictable:

- Size of the object. Make it too small and no value of luminance will make it reach its surroundings.
- The Position. Sometimes a 0.1 change in x, y, or z value away or towards other assets in the scene makes the difference.
- Refresh the Camera position while working every now and then. Just move the 3D Preview around. This one is weird but made a difference in long sessions.
- You can use "Bloom" and "Starburst" to help the effect. Not too soft or it diminishes more than it helps the spreding of the luminance.
- A Luminance value of 1 is by far not enough when you are using a small object or are farther away from the surroundings. Go HIIIIIIGH!
Hope that helps a little.
CHeers, Klaus
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KlausK

#6
These examples are done with TG`s own Sphere object.
The 1st one is done using only Luminance. Very high values, not very easy and comfortable to control.
The 2nd and 3rd are done using both Luminance in the sSheres Surface Shader and a Light Source.
That is a far superior way to achieve this effect. You have separated control over the surface of the object
and the area you want to be lit.
Since there is no grouping feature in TG (yet) you have to move the object and the light source to the same coordinates one by one.

CHeers, Klaus

ps: Increasing "GI Cache Detail", "GI Samlpe Quality", and "GI Blur Radius" in Render node / Render GI Setting / Prepass Tab adds to render time but gives much better results.
I had the values set to 6 | 6 | 32. Render time went up from 30sec to 2m30s. When only using Luminance on the sphere object.
With the light source inside the sphere there was no need to go that high with the values.
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WAS

#7
Here is a tent i plan on releasing from Tactical_Beard (Sketchfab) that I created a night time luminous map for as another more subtle example. There is a light source inside the tent to complete the effect from the undersides of the open parts (it has no bottom).

Additionally the campfires I reuploaded in TGO format use glows as well in the File Sharing section.

The issue is how TG handles luminous objects which dev assues is the same as light sources but interact entirely differently with the atmosphere. :P Hmm. I'll never believe that one until the results are the same with point based lighting and no artifacts.

Matt

#8
You might want to try enabling "Path tracing on surfaces", and "Robust adaptive sampling".

Quote from: WASasquatch on December 06, 2018, 01:23:46 AM
The issue is how TG handles luminous objects which dev assues is the same as light sources but interact entirely differently with the atmosphere. :P Hmm. I'll never believe that one until the results are the same with point based lighting and no artifacts.

I'm pretty sure we've never said anything like that. You might be mixing this up with my explanation/demonstration that a population of bright objects is usually a better source of GI than a cloud containing bright spots (but neither are as good as light sources). The reason I showed that is because I misunderstood what you were trying to do at the time, so my demo turned out to be irrelevant.

We all agree that GI doesn't work as well as proper light sources, and it's especially difficult in atmosphere.

The path tracer should give you better results (but doesn't change how atmosphere is rendered). I might be able to add object-based area lights in future to render this kind of thing more efficiently, and that would also work in atmospheres.
Just because milk is white doesn't mean that clouds are made of milk.

jaf

Haven't messed with luminosity much lately.  I did do a project a while back with a large sports scoreboard.  The individual "scoreboard lights" were set up as individual objects in a row/column format similar to a LCD -- the "on" elements used a luminosity of 2.  Most of the rest of the lighting was spot lights/ light sources, though the lettering used luminosity.

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WAS

#10
Quote from: Matt on December 06, 2018, 02:33:54 AM
You might want to try enabling "Path tracing on surfaces", and "Robust adaptive sampling".

Quote from: WASasquatch on December 06, 2018, 01:23:46 AM
The issue is how TG handles luminous objects which dev assues is the same as light sources but interact entirely differently with the atmosphere. :P Hmm. I'll never believe that one until the results are the same with point based lighting and no artifacts.

I'm pretty sure we've never said anything like that. You might be mixing this up with my explanation/demonstration that a population of bright objects is usually a better source of GI than a cloud containing bright spots (but neither are as good as light sources). The reason I showed that is because I misunderstood what you were trying to do at the time, so my demo turned out to be irrelevant.

We all agree that GI doesn't work as well as proper light sources, and it's especially difficult in atmosphere.

The path tracer should give you better results (but doesn't change how atmosphere is rendered). I might be able to add object-based area lights in future to render this kind of thing more efficiently, and that would also work in atmospheres.

I'm pretty sure clouds were just a silly demonstration and the conversation was about manually having to place lights, that interact with nebula correctly, and not being able to populate objects that are luminous. Lol It was about workflow and a need for a light-source populator because luminous objects suck really bad in standard renderer.

Also it's ironic cause the clouds orbs created proper lighting from what i remember despite complaints about renderer picking them up, etc. Probably because the orbs are transparent and light is emitted from each point within.