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Working with Kray

Posted: Wed Mar 02, 2016 4:59 pm
by thibault
Hi,
Yes, i'm really trying to work with Kray.... and i'm happy with result but not for the time.
Kray in Low preset i choose in drop down menu - no cache irradiance - 30 cm GI resolution - Sky plugins.
If you have idea to decrease the time render, i take !
Thanks in advance

I forgot : Render in 4000 X 2000 (Remember talk for BARCO)

Re: Working with Kray

Posted: Wed Mar 02, 2016 5:12 pm
by thomas
I'm leaving this one to Janusz, the master! :-)

Nice work by the way!

Re: Working with Kray

Posted: Wed Mar 02, 2016 5:36 pm
by thibault
Thanks Thomas !

Re: Working with Kray

Posted: Wed Mar 02, 2016 8:05 pm
by Janusz Biela
Here you have minimum good stuff for QMC:
ScreenShot203.png
ScreenShot200.png
ScreenShot201.png
ScreenShot202.png
where is zero value: option does`t work (because QMC) - you do not pay attention for this.
Always shoot a lot photons because then more you fire then better information average you get. At least 5.000.000 for final render.
For exterior you do not need so dense photon (30 cm) information and is enough 0.5 m (in bigger space even you can increase up to 1.0 m, for example whole street)

For fast preview use this:
ScreenShot204.png
For Path Tracing same setup but you can put zero photons because in this system you do not define amount of photons - only noise level (by FG rays).

Re: Working with Kray

Posted: Thu Mar 03, 2016 9:19 am
by thibault
Many thanks Janusz but, unfortunately, LW native is always more fast - 25 mn LW / 36 mn Kray - for my test part of 4000 X 1343.
And the result, for the client, is similar.
I put 500 000 photons for decrease render time.
I keep testing and thanks again

Re: Working with Kray

Posted: Thu Mar 03, 2016 10:11 am
by ideart
Hi, are you using Lw's carpaint or conductor?
Kray is really slow rendering them.

Re: Working with Kray

Posted: Thu Mar 03, 2016 10:18 am
by Janusz Biela
It can be, lately LW is really fast but personally I doubt because if you compare two renders you will notice in LW always bad AA (especially problems with LimitDR) and reflection noise blur.
To achieve same effect like in Kray you need increase quality in LW and this situation make LW slower around 30-80% then Kray.

Because I do not know LW native I can not compare. Generally LW lately is really fast and comparing both renders now (K2-LW) is senseless - differences are too small :wink:

In Photon Mapping (include QMC - sampling are based on PM, of course) is doesn`t matter amount of photons if we talk about speed render. Do not use small amount like you said 500.000, is just too dangerous because you will not fill all corners with information.
Difference between 500.000 and 5.000.000 is only a couple seconds and has no influence for whole time render...even better: having more complete photon map information you get better and faster render.

Re: Working with Kray

Posted: Thu Mar 03, 2016 10:22 am
by Janusz Biela
ideart wrote:Hi, are you using Lw's carpaint or conductor?
Kray is really slow rendering them.
problem with them is they have limited documentation and G, can not guess when writing in code support for them. Also I got information some Nodes has bugs and G. must avoid this by special codes in Kray. This all make slower render. Dielectric gives hot photons - do not use it.

Re: Working with Kray

Posted: Thu Mar 03, 2016 10:33 am
by thomas
Hi Thibault,

It's very possible that LW is faster for this scene. Kray is a lot faster than LW at blurry reflection shading, but it looks like a lot of this scene is either zero reflection (like all the stone and street) or 100% sharp reflection (like the glass), so Kray speed gains might not apply. In the same vein, Kray is great at mucho photons bouncing around, but again, in an exterior scene 2 bounces are enough.

Disclaimer: I'm still using LW 11.6.3 so I don't know much about the latest improvements.