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Glass and Denim

Posted: Wed Jul 11, 2018 10:49 pm
by FarbigeWelt
This is just playing around with Glass and Volume settings. There is an especially fancy material there: Denim. For my taste default settings are a bit out of line. However it is fun to use. In my opinion more useful is a nice wood material and a brick material with offset for 3d look and free shapeable tiles. Who coded Denim material could also be able to add some further goodies.
Glass Material with Volume and a Denim Cube
Glass Material with Volume and a Denim Cube

Trying Velvet

Posted: Thu Jul 12, 2018 10:49 pm
by FarbigeWelt
Velvet with its advanced three parameters is a bit beyond my current understandig of what is happening.
EDIT: Picture replaced after 6 h rendering, CPU BiDir (i7 4770K, 3.5 GHz), comment added.
Velvet with Volume, 6h
Velvet with Volume, 6h
Well it is not a pure velvet material, it is a mix with a null, the material has its own internal volume.

https://wiki.luxcorerender.org/LuxCoreR ... als_Velvet
"p1, p2, p3
These are three polynomials that define the appearance of the fuzz. They are rather abstract, so its best to just play around until you get a good result. "

Seems to be exactly like in the description. Playing with velvet, opacity and volume delivers nice and sometimes surprising results. The test shape in my picture is all made from the same material.

Trying Velvet 2

Posted: Fri Jul 13, 2018 7:27 pm
by FarbigeWelt
Same material setup but with different colors.
Velvet 13 h, 1184 samples
Velvet 13 h, 1184 samples
Material
Material
Material Volume
Material Volume
Air
Air
Obviously I made a mistake setting up air. I'm wondering what happens with correct settings.

Re: Test scences GPU Path vs CPU BiDir

Posted: Fri Jul 13, 2018 8:08 pm
by B.Y.O.B.
Mesmerizing :)
FarbigeWelt wrote: Thu Jul 12, 2018 10:49 pm Well it is not a pure velvet material, it is a mix with a null
Instead of mixing with null, use the opacity slider of the material. This renders a lot faster.

Mesmerizing

Posted: Fri Jul 13, 2018 8:20 pm
by FarbigeWelt
Thanks, B.Y.O.B
Instead of mixing with null, use the opacity slider of the material. This renders a lot faster.
Well, you have to try it. It makes really a huge difference to use null material and mix instead of using opacity only. At least in version 2.0 with CPU Bidir. I will show the difference soon.

Null Material and Opacity Study

Posted: Fri Jul 13, 2018 8:45 pm
by FarbigeWelt
Null Material with Volume
Null Material with Volume
Null Material with Volume.png (120.84 KiB) Viewed 5932 times
Null Material with Volume Transmisson Colored
Null Material with Volume Transmisson Colored
Null Material with Volume Transmisson Colored.png (137.42 KiB) Viewed 5932 times
Velvet
Velvet
Velvet.png (132 KiB) Viewed 5932 times
Velvet with Opacity and Green Volume
Velvet with Opacity and Green Volume
Velvet with Opacity and Green Volume.png (142.22 KiB) Viewed 5932 times
Velvet with Opacity and Green Volume mixed wiht null.png
Velvet with Opacity and Green Volume mixed wiht null.png
Velvet with Opacity and Green Volume mixed wiht null.png (145.63 KiB) Viewed 5932 times
Velvet with Opacity and Green Volume mixed wiht null and no opacity
Velvet with Opacity and Green Volume mixed wiht null and no opacity
Velvet with Opacity and Green Volume mixed wiht null an no opacity.png (144.15 KiB) Viewed 5932 times
Velvet with Opacity and Green Volume mixed wiht null and 0.75 opacity in mix
Velvet with Opacity and Green Volume mixed wiht null and 0.75 opacity in mix
Velvet with Opacity and Green Volume mixed wiht null and 0.75 opacity in mix.png (146.92 KiB) Viewed 5932 times

Glossy and null

Posted: Fri Jul 13, 2018 11:24 pm
by FarbigeWelt
EDIT: Picture replaced with long time render.

Yet another miracle: reasonable use of glossy coating. At the moment I did not get what I intended. Hoping soon to hit my target.
Glossy Coating mixed with null CPU BiDir 6:45 h 1017 Samples
Glossy Coating mixed with null CPU BiDir 6:45 h 1017 Samples
8-)

Matte Study

Posted: Sat Jul 14, 2018 6:32 am
by FarbigeWelt
Matte is easy to understand and use in combination with volume. After changing setup for a few samples look gets predictable.
Matte pure and blue volume
Matte pure and blue volume
Matte opacity 0.5 and blue volume
Matte opacity 0.5 and blue volume
Matte mixed with null colored white and blue volume
Matte mixed with null colored white and blue volume
Matte mixed with null colored grey and blue volume
Matte mixed with null colored grey and blue volume
Matte mixed with null colored black and blue volume
Matte mixed with null colored black and blue volume
Matte opacity 0.5 mixed with null colored grey and blue volume
Matte opacity 0.5 mixed with null colored grey and blue volume

Re: Test scences GPU Path vs CPU BiDir

Posted: Sat Jul 14, 2018 9:33 am
by B.Y.O.B.
I can reproduce a difference between mix with null and equivalent opacity.
It could be a bug, or maybe it is an expected behaviour, I'm not sure.
I think it would be good to log this in the LuxCore bug tracker, with an example scene.

Glossy Coating is difficult

Posted: Sat Jul 14, 2018 11:06 am
by FarbigeWelt
Glossy Coating in blender addon has a missing parameter or does not behave as it should.
Where possible base material's absorption is 0.75.
Glossy Coating Glass vs Glossy
Glossy Coating Glass vs Glossy
Glossy Coating Mirror vs Glossy
Glossy Coating Mirror vs Glossy
Glossy Coating Null grey vs Glossy
Glossy Coating Null grey vs Glossy
Glossy Coating Matte grey vs Glossy
Glossy Coating Matte grey vs Glossy
Glossy Coating abs 2 Matte grey vs Glossy
Glossy Coating abs 2 Matte grey vs Glossy
I would expect from glossy coating a pure glossy shell with a parameter like shell's thickness. Thikness might be in percent of the object's dimensions or in scale units similar to absorption (aka absorbance). Null material behaves quite strange it seems to have much higher priority than glossy coating.