Rendering resulting weird noise and dirty in Emission Shader

I have bad thing when i rendering in perfectly but the noises in Emission Shaders are really annoying,when I used a Principle Volume with 0.005 density and 0.975 Anisotropy
Anyone how to fix it?


By the Way I am using Cycles to render

Why don’t you mix a normal emission material to have the light while for the camera the volume emission is visible using the light pass node as a factor for the mix shader node? You would be free from the noise problem.

Okay But How?

I will create a scene here to show you. Just a minute.

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Here is the result:

And here is the node setup I created:

By the way, Why are you using density and anisotropy? Isn’t the emission you want?

I’m assuming you are using a volume shader in the world settings? Then you might want to try the different “sampling” options:

If you have used an object with a volume material instead, you will find the same setting in the material tab.

So it needs to chanrg or what?

Depending on the scene, it’s not always the same one that works best, some will give more noise and some less. There are only 3 options, you should try them to see if one of them has less noise.

I changed it and unfortunately nothing work at all

I believe you are using too less samples. How many samples are you using to render the scene?

I used to render about 256 samples

I think it’s too less for that kind of thing. You should use at least 1000 to get a really smooth result. never less than 500 or 600.

Of course it may depend on what exactly you are trying to do, but if having the cool neon glow is the only goal I would seriously consider doing it in post production, rather than messing around with volumes.

You will have much more control, much less noise, and will render much faster.

For simple test you can make do with the fog glow filter (under filter>glare in compositor IIRC), later you would probably need to mask the sources, so either cryptomattes or ID masks, whichever you prefer.

But yeah, employing volumes seems excessive to me based on the shared screenshot

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That’s why I suggested using the mesh light to produce the glow instead of the volume. It’s really inefficient and a heavy render process.

I also thought about the compositor, but explaining the process of mixing shaders and using the light path node outputs as a factor was easier for me.

op is using a volume in the world, not the lights.

He is using the noisiest most render intensive way to get a glare effect.

@Maeve_Sterling, look into @Adam3141’s suggestion above. you do not want to be using a volume to create a glare effect unless you want to throw thousands of samples at it. this effect should be done in post processing.


Conversely, forget the volume and use a bokeh blur to get the same effect. Way faster render times, and clean result.

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Understood. I imagined the scene in a completely different way.