Burned out pixels

[billbeaumont]

Hi,

I am trying the Octane Demo on a Quadro FX 4600, win 7 ultimate, dell t5500 workstation.

My renders have small spots on them where pixels are incredibly over-exposed. These seem to appear at random. The higher the number of maxsamples I set, the more of these specs appear.



Can anyone tell em why this is happening?

Thanks,
Bill

[kubo]

Those "hot pixels" are also known as "fireflies" 2.3, you can check the forum, or you can read an explanation by Radiance himself here http://www.refractivesoftware.com/forum ... ies#p27076, or you can buy a license and have access to the pre-release 2.3 that kills them with ease (and that's just a pre, the final is going to blow our minds for sure!)
Also you got some smooth issues in your model, did you check the smooth bool in your materials?

[billbeaumont]

Hi Kubo,

Thanks for your reply. It's reassuring that they have a fix for this. I want to buy the full version but needed to be sure these fireflies were avoidable.

As for the smoothing, the render was just a quick excercise to see what OR could do so by no means a finished image - but thanks for pointing them out, and particularly thnaks for pointing out the smooth bool... I'm going to hunt for that feature next time I have a dabble with the software!

Many thanks,
Bill

[billbeaumont]

Hi Kubo,

One more thing (as I don't have authorisation to view the thread you pointed me to)
How does the software kill the fireflies? My main concern is if it is practical for killing them in an animated sequence rendered through the Maya plugin.

[kubo]

sorry my bad, I'll quote:
"Hey,

fireflies are normal, they are a natural side effect of pathtracing, unbiased rendering.
there are techniques to get rid of them, one being: http://www.refractivesoftware.com/forum ... f=21&t=878 (also is good for the aliasing in your image),
and defly: http://www.refractivesoftware.com/forum ... =21&t=2597
they are long paths, reflective caustics.
the next release, beta 2.3 will have a new algorithm that explores these caustics and renders them completely, thereby converging to an image without fireflies.

Radiance"

Well in the current pre-2.3 with pathtracing there hardly is any damm fly at all, besides 2.3 is really sweet (and it's not final yet) and the oncoming algorithm will kill them just like MLT but faster and better!

[radiance]

note that beta 2.3 is not released yet, but very stable and in use by a lot of customers,
and it's not available as a demo yet, so only customers with a 99 euro beta license have access to it.

The soon coming 2.3 v5 update offer some decent speedup/optimization, an optimized solution to the energy loss (black rings sometimes / rarely seen around glossy materials, and more bugfixes and importance sampling giving even less fireflies, theoretically everything should converge firefly free, except specially made render engine stresstest scenes)

Radiance

[kubo]

and of course add the material library on octane live, and all the neat oncoming things... yeap, I'm excited!!!!