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Hot Pixels, Hot Pixels Hot Pixels

PostPosted: Fri Apr 26, 2013 8:59 am
by RGUS
OK... call me a dummy for not posting in the right forum... but this will do, since it Poser and Octane Plugin... but how the hell do you stop the hot pixel thingy... I mean... I render for 32 hours.. and still they are there... what do I need to change... being a dummy and all.

Re: Hot Pixels, Hot Pixels Hot Pixels

PostPosted: Fri Apr 26, 2013 9:05 am
by face_off
Set hotpixel_removal to 0.
Increase caustic_blur to 1. (OK, 1 might be too much, but it's a start)
Use the 1 poly, singlesided emitters that the Create Emitters From Light scripts generates
If hotpixels are behind a specular material, there are a bunch of way to get rid of it which I can describe if needed
There are also "white balance" hotpixels, that are usually a few pixels big - adjust white balance to fix

If you need to render for more than 10 mins, something is setup wrong :-)

Paul

Re: Hot Pixels, Hot Pixels Hot Pixels

PostPosted: Fri Apr 26, 2013 9:11 am
by RGUS
face_off wrote:Set hotpixel_removal to 0.
Increase caustic_blur to 1. (OK, 1 might be too much, but it's a start)
Use the 1 poly, singlesided emitters that the Create Emitters From Light scripts generates
If hotpixels are behind a specular material, there are a bunch of way to get rid of it which I can describe if needed
There are also "white balance" hotpixels, that are usually a few pixels big - adjust white balance to fix

If you need to render for more than 10 mins, something is setup wrong :-)

Paul


Sounds good Paul
These are candle lights.. where do I find "hotpixel to 0"
And bunch of ways would be good... I have to convince more people to use Octane... slow... but happening.
Cheers mate

Re: Hot Pixels, Hot Pixels Hot Pixels

PostPosted: Fri Apr 26, 2013 10:54 am
by face_off
"hotpixel_removal" is under "imaging". "imaging" can be one of your most useful nodes.

Candles are special cases - and Wim has done a lot of experimenting with them. In summary:
1) Don't have a glass surround around the candle
2) Use the least possible polygons for the flame.
3) Even with 2), the flame emitter geometry is unlikely to be big enough to give you a quality render, so put a bigger low-poly sphere or cube around the flame geometry, set it to opaque 0, and set it up as an emitter - it will do a better job than the flame than the flame can do.
4) Use a fill light (or low power "texture environment") - don't rely on the candle to light the scene

Check with Wim - he knows this area better.

Paul

Re: Hot Pixels, Hot Pixels Hot Pixels

PostPosted: Fri Oct 04, 2013 9:39 am
by samhal
Cool Thanks Paul...I too was struggling with this candle thing.

Using the technique above I came up with this. 4210 [email protected]:36 minutes. Hot pixel at zero. I did however use one of the clear glass materials in LiveDB.

Image