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hotpixel reduction

PostPosted: Thu Nov 22, 2012 4:40 pm
by cnolte
Hi Paul,

I love the plugin and I am somewhat a newbie with the Octane rendering engine so please forgive my naive question. I have noticed in the plugin that the hotpixel slider default is set to 1.0. In some of my renders I have been getting a lot of fireflies. Should I be lowering the slider towards 0 (as per Radiance's mini-tut on reducing hotpixels for Octane 2.3 build) or be adjusting the roughness of my glossy materials (read somewhere in another post); or both? It seems that I get more hotpixels in renders that have objects with thin geometry and glossy materials assigned (i.e. individual hair elements such as eyelashes).

Thanks,
Christof

Re: hotpixel reduction

PostPosted: Thu Nov 22, 2012 8:27 pm
by face_off
Hi Christof

I haven't had enough firefly issues to need to use the hotpixel slider yet.

What lighting are you using? Sunlight, an environment map or emitters?

Sometimes hotpixels are just a glossy with too much specular - so reduce the specular or bump in that case.

I've also found that there fireflys can take longer to be rendered out of HDR enviro maps as opposed to LDR maps. And they can take longer to render out when using color emitters rather than blackbody.

Paul

Re: hotpixel reduction

PostPosted: Thu Nov 22, 2012 9:15 pm
by cnolte
Hi Paul,

I using Sunlight as my lighting.

I will check my speculars.

I haven't let any of my renders go very long (maybe 35%), before moving onto something else -- I have been testing as many props and figures as I can throw at it, and I am very pleased with the overall results. I have some renders with no hotpixels and some with maybe a dozen but they are composed of different characters/props, so I have been trying to determine what are the sources of the fireflies.

I will look at my speculars and let a render go longer.
Thanks,
Christof

Re: hotpixel reduction

PostPosted: Thu Nov 22, 2012 9:43 pm
by face_off
Sounds good. If you post an example for a render with hotpixels that might help track it down.

Paul