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Re: Retroreflector

Posted: Fri Aug 23, 2013 12:41 am
by andyjacobs
Hey, Thanks everyone for the suggestions. Eric, that looks great and even tho it might not be physically correct I think it gives the emitter type effect when reflecting the light well.

I have had a play at making a material based on your description which I think could be good enough for what I am trying to achieve.

Image


Angled, so its not reflecting the light, with matt white for comparison:

Image



Front on, reflecting the light on part of the curved surface, with matt white for comparison:

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Front on, reflecting the light with, shiny (roughness 10) for comparison

Image

Re: Retroreflector

Posted: Fri Aug 23, 2013 1:40 pm
by eric nixon
Hi Andy, in my material I left the R0/R90 at 0 strength (black), I used two other bsdf, one for spec @8%, one for diffuse @17%, theres no harm in putting the spec in the sss bsdf if you want a gloss finish (because roughness is @7)

Good luck.

Also beware the transparency cant be at max or the attenuation wont work.

Also curious about those stripes on the back surface?

Image

Re: Retroreflector

Posted: Thu Aug 29, 2013 1:28 pm
by andyjacobs
Hey Eric,

Thanks for taking the time to reply again. Sorry I haven't had time to get back to this lately.

For the diffuse and spec layers, I assume the percentages are layer weights? What colours did you put in the r0 and r90 channels and what roughness did you use?

Sorry the lines were when I tired having an object intersecting with the SSS as I wasn't sure if it needed a backing. The SSS was around 0.8mm and the backing was about 0.1mm inside it and possibly coincident at the back. I tried with and without and it didn't seem to make any difference.

Cheers,
Andy

Re: Retroreflector

Posted: Thu Aug 29, 2013 2:23 pm
by eric nixon
Hi Andy, the percentages are BSDF weights. How much weight you give each component is up to you, also the colour / roughness doesnt matter, do what looks right.

Re: Retroreflector

Posted: Sun Sep 01, 2013 2:49 pm
by AndreD
eric nixon wrote:No, he was right!

Success! :D Heres 2 images where just the camera has moved, the front panel of the shirt has less than 1mm thickness with an sss based mxm, ND 1.00001, pos assym .8, roughness 7, scattering 6000, attenuation 40nm. NO MAPS USED
Would be nice, to see this effect in a small camera-animation ;-)