Solution and Question: Lighting issues- Volume Absorption

[Zangk]

Issue:

Whilst working on my overly-bloated animated project, I soon discovered that my lights were doing some strange things. Sometimes my entire scene would go black, at other times it would go dark red, and once in a while return to normal:

That was a little frustrating considering that it is hard to add and change materials well if you cannot see them. There were no answers on the internet.

I clicked about turning off and on different parts of the scene until everything returned to normal. It was my lamp glass.

Solution:

The nodes that I used were causing the issues. I thought it was the lack of BSDF but the problems returned.

It turns out that it was the Volume Absorption. I took it out.

Fixed:

Yes, I added a Mix Shader, probably needlessly , but such as it is.

So if you have any unexplained lighting issues, and none of the other fixes work, perhaps you have something wrong with your nodes?

Question:

By the way, what is Volume Absorption supposed to do, and why would it have interfered with the entire scene’s lighting?

[FedPete]

Material output ‘Volume’ is used for volumetric objects like smoke, fog, dust.
You can use a Volumetric BSDf node for it.
Or create a node setup using the ‘Volume Absorption’.

It’s more advanced stuff, needs a high sample Cycles rate.
Eevee works a bit differently.

It’s fun to experiment, but try to stay focused.
Do the big parts first (objects, layout, composition, animation).
Lighting, smoke, materials can de done in a second pass of the project.

But, I think you get the notion now, that for animation you need to plan ahead.
Think about the story, make some storyboard (sketches of main events).
Make a rough design, and animated a bit to test stuff.
Then more and more go into details.
… yes, a lot of work

But we’re having fun !