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Testing the sss parameters. Block is 3 x 3 x 0,5 m, so it is a fairly large piece of transparent material
Nd = 1,6
Lightbeam is created with a small emitter inside a reflecting parabola, thereby achieving an almost collimated beam.

abs 0,1 scatter 0,1

abs 0,1 scatter 0,5

abs 0,1 scatter 1

abs 0,5 scatter 0,1

abs 0,5 scatter 0,5

abs 0,5 scatter 1

abs 1 scatter 0,1

abs 1 scatter 0,5

abs 1 scatter 1


Dane

nice tests usefull

Very nice !

Thank you for these tests

Very nice tests, thank you very much!!!

Very useful tests. Thankyou.

Tim.

what is bsdf properties and emmiter property? (strength)


thanks for this nice post showing results of sss settings!

i'd like too to know which settings you used

great tests

Bookmarked for sss creation. Thank you!

Thank you all.

what is bsdf properties and emmiter property? (strength)

The sss abs and scatter coeeficients are written above each image. The material is a single layer bsdf with subsurface added holding Nd =1,6 and all reflectance and transmittance values as high as possible

The emitter is 25 Lumen (Orange)
The parabola is a smooth 20 Nd single layer .

Cheers Dane

Very cool tests! Thanks for info.

Hi Dane.

I have one question.

In your test, ab =1 is largest scale.

but in the maxwell material editor, we can raise up to 1000.

then, what is that mean?

sandykoufax wrote:Hi Dane.

I have one question.
In your test, ab =1 is largest scale.
but in the maxwell material editor, we can raise up to 1000.
then, what is that mean?

The block can become even darker (until it is black).
Absorbance completely replaces attenuation when SSS is turned on.

Hi Thomas, thanks for answer.

But I'm still not clear.

What is the unit of the Absorption param?

I thought that scattering param is based on percentage(0~1.00).

However, absorption could be up to 1000.

You said that ab replaces attenuation.

Then, dose this param use attenuation unit?

When I set my attenuation to 15mm, and added SSS layer on it.

If I set the absorption value to 15, is this work as 15mm ?

sandykoufax wrote: When I set my attenuation to 15mm, and added SSS layer on it.

If I set the absorption value to 15, is this work as 15mm ?

They are related in physics. The absorbance can be seen from the "Beer-Lambert" law, but I am not sure off-hand how to convert absorbance into optical loss dB/km (I need to look it up some time)
http://www.maxwellrender.com/forum/view ... hp?t=17142

... so I do not know what would be the equivalent of 15mm attenuation ... Once you add the SSS layer then your attenuation setting is gone and you need to determine by trial and error what the equivalent absorption value would need to be.

hmm, thanks for quick reply, Thomas.

The only solution is just try and error.

but I don't understand why NL make this param's max value to 1000 instead of 1 (beta's).