noise reduction

[slepy8]

hey guys.

Just encountered a problem:

https://www.dropbox.com/s/o2dlsny58d818 ... ienny1.png

Directlighting - 40.000 samples About 1 hour rendering.

I did it on 20.000 and the result was quite similar. The noise was quite the same.

What do I do wrong?

[aoktar]

please try cameraimager -> hotpixel
betwen 0.1-1

[slepy8]

ok it works in some way. It doesn't decrease hotpixels to 0, but it's better. Is there anything else I can do?
Something to remember during scene setup to avoid these hotpixels? Or maybe some render settings?

[bepeg4d]

hi, which kernel are you using?
currently there is an issue with a lot of ies lights in pt and pmc, if you switch to dl4 you should see a clean image in shorter time, but you loose all the coustics
ciao beppe

[slepy8]

well in fact this is DL kernel.
I thought that more maxsamples will give me cleaner images, but it's a bit opposite. The longer it renders, the more hotpixels pop up..

I can see it happens mostly in places where there is very strong light and in the areas close to some glossy materials...

[pokeit]

I was having similar issues with one scen because the scale was wrong (my scene was tiny) if not already try to set real world scales...

Cheers!

[slepy8]

heh.. in fact in this case it's exactly opposite

What's 20cm tall in reality, in this scene is 200cm tall...

I think I just need to render bigger images and scale them down.
It worked last night.

[iFloris]

heh.. in fact in this case it's exactly opposite

What's 20cm tall in reality, in this scene is 200cm tall...

I think I just need to render bigger images and scale them down.
It worked last night.

We had a similar problem some time back.
It really is imperative that you set the scale right, so 20 cm = 20 cm.
The reason for this is that all the lighting calculations and ies files and such work on the assumption that 1 cm = 1 cm.
The fireflies might well be the result of the ies lights normally used in rooms 80m3 now having to light a room 800m3.
You adjust the power or the efficiency to compensate and before long you are pushing 100% efficiency and 1000 gigawatt spotlights!
Scale the scene back to a real world equivalent and you might see much better results.

[slepy8]

thanks for the tip. It makes sense.

I'll test it today.

[slepy8]

I changed sizes.
But unfortunatelly no effect.

Hot pixels pop up in the same places..