Curtain problem

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vgabex
Posts: 132
Joined: Sat Dec 09, 2006 2:47 pm
Location: Hungary

Curtain problem

Post by vgabex » Tue May 08, 2018 11:33 am

Hi,

What's going on here? I'm trying to render this scene. Horrible rendering times with curtains. Can somebody help me? Thanks!
curtain_problem.jpg
curtain_problem.jpg (229.23 KiB) Viewed 986 times
curtain materials and K3 settings here:
Attachments
K3_settings.zip
(251 Bytes) Downloaded 60 times
curtain_transparent.srf
(48.15 KiB) Downloaded 58 times
curtain_dark.srf
(52.26 KiB) Downloaded 61 times

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Janusz Biela
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Location: Finland
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Re: Curtain problem

Post by Janusz Biela » Tue May 08, 2018 12:03 pm

I do not need your scene to recognize problem :D
Here is my surface for transparent curtains.
curtains_white_transparency.srf
(45.48 KiB) Downloaded 75 times
Please notice I used KrayShader plugin with very low QMC and very low refraction setting.
This will speed up render, noise is not so much horrible (can be removed by ID mask under Photoshop)

Test it and tell me it helps.

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vgabex
Posts: 132
Joined: Sat Dec 09, 2006 2:47 pm
Location: Hungary

Re: Curtain problem

Post by vgabex » Tue May 08, 2018 12:22 pm

Thanks Janusz!

Meanwhile I tested out a fast solution:
compare_03.jpg
compare_03.jpg (238.69 KiB) Viewed 978 times
srf:
Attachments
curtain_transparent_simple_fast.srf
(48.37 KiB) Downloaded 80 times

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Janusz Biela
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Location: Finland
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Re: Curtain problem

Post by Janusz Biela » Tue May 08, 2018 3:05 pm

Thanks.
Just remember that white curtains need transparency and refraction blur...and this make calculation long (refraction blur). Otherwise surface will look artificial. To avoid this complex calculations (transparency+refraction blur) we use KrayShader which OVERRIDE general settings for this surface.
General setting for QMC can be 1000 rays which is good for interior to remove noise on the walls but is not necessary use these 1000rays for curtain!
Is enough force (by shader) surface to use 100 rays for QMC and very, very low amount of rays for refraction (50 rays instead 500).
Curtains are bright - noise will be less visible.

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