Blender dark pixel artifacts while rendering - How can i solve this?

Rhav

Hey

I've been recently trying to render an animation, but i have an issue with the light. Here is th eproblem.

As you can see those pixels are horrible and shouldn't be there. 
Here are some info about my project:

-There is only one light

-All render options are set to default

-I tried upscaling the samples, but that didnt seem to work

-I've tried to render other scenes with the same light before this, but this is the only scene that gives me problems

-The objects are simple cilinders, there is no non-manifold geometry or something like that.

What do you think causes those visual artifact?

Thanks in advance for your answers.

Tiles

Hard to understand what you mean. There are no single pixels sticking out, which would be fireflies most likely. And the stains could also be the texture.

Eevee or Cycles? I guess with animation you use Eevee. Try increasing the shadowmap size. Are the lights baked?

Rhav

this is cycles, and the texture is just a simple white (the default color of the the diffuse node). Sorry i forgot to say this, but everything is at a default value, that's why this bothers me. Lights are not baked. The only light comes from an emissive shader that's part of the lamp.

Tiles

Ah, emissive lights. This is your problem here. I would not use it for animation if possible. Emissive lights produces lots of fireflies and artifacts by design, and takes eons to show a clean result. It is nearly impossible to use it in an animation without flickering.

I unfortunately haven't rendered with Cycles for a long time. Lots has changed since then. Does Cycles even have square sample settings still? But try to clamp the light, and go crazy with the samples. And play around with the bounces too. Emissive lights needs lots of samples.

Another thought is that the denoiser is having fun here. Try without. Then you might also see all the fireflies.

Rhav

Ok i think i got this. I simply lowered the noise threshold from 0.1 to 0.001 (maybe an overkill).
Here is the result.


Still weird though. As i said i used this same light for other similar scenes and nothing like this has ever happened.
Here is a previous example.

Thank you again for you time

Rhav

Oh and i forgot to say that i also enabled the gpu on the denoise, but i don't know how much this had impact on the final result.

Tiles

Glad you found a solution. Allowed is what works