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Glass LED light

Posted: Sat Mar 09, 2013 11:20 am
by clausgs
HI

I am doing some furniture's with glass shelf's, on the back edge of the glass shelf there is a LED light clip. In real life the LED light clip will lighten up the glass material and will show clearly on the edges of the glass shelf, but in Octane I can not get it right.
The light i use is 5 circles placed inside the LED clip (4mm diameter circles with just a diffuse color and black body light)
I have tried with different glass materials from the database, and also with a glossy material with transparency and high secular. but can not get the correct effect.
Is there any one that can help me on this issue???, i guess it is a combination of the right light setting and the right glass material.

Thanks in advance.
Claus

Real life
Image

My render
Image

Re: Glass LED light

Posted: Sat Mar 09, 2013 6:29 pm
by gabrielefx
you should simulate a fake (sort) of translucency on borders

Create the glass box, add a specular mat
add a scattering medium, leave all default
in emission add a blackbody texture with low values

simulate the leds with mesh circles, merge all of the in one single mesh. Add a diffuse mat + blackbody texture with low values

Re: Glass LED light

Posted: Sun Mar 10, 2013 12:55 am
by clausgs
HI

Thanks for your reply.

Not sure i understand 100%
1
Create a glass panel and add a specular material to it, just use the default settings for that material. understand.
2
add a scattering medium. This i dont know what is and how to do, and where to add it?
3
in emission add black body texture. is this a part of the scattering medium?

Question
So what you suggest leads to that Octane do not simulate this very well compared to real life,,, and therefore I will have to make the effect happen with some kind of fake solution?

Claus

Re: Glass LED light

Posted: Sun Mar 10, 2013 2:10 pm
by Andreas.visjon
leads to that Octane do not simulate this very well compared to real life
I dont think so, but to simulate it, you need to make sure your scene is like in real life.
The glas shelf is not only one objekt with glas material.
On the border is a different material with a very diffuse reflection/refraction, around 1-2mm. In this
material the light get reflected, so it can go around, and finaly on the outer border there is
some rough surface where the light (can) come out.

I guess the calculation time is very high for this kind of light, indeed it is better to fake this.

I did a quick test. Just rendered some few samples.

Image

Ciao
Andreas

Re: Glass LED light

Posted: Sun Mar 10, 2013 11:23 pm
by clausgs
HI Andreas.visjon

Thanks for showing me real examples, For me it is more about getting the right visual effect than doing a simulation of light, In real life that type of shelf and LED light will help to eluminate the inside of the cabinet, what gives a nice looking cabinet. so fake or no fake not sure yet.

Question
on the no-fake you made, is the glass shelf edge at the same plane as the side panel surface??, and that is why no light coming out on the side edges of the glass shelf?
Normally there is a 2 to 3 mm gap there..

How long did the render take, No-fake?
What type of render did you use AO?
What settings did you use for the 1 to 2mm material on the edges of the glass shelf for the no-fake test?

Thanks
Claus

Re: Glass LED light

Posted: Mon Mar 11, 2013 1:44 pm
by Andreas.visjon
Hi,
on the no-fake you made, is the glass shelf edge at the same plane as the side panel surface??,
No, there is some space, but with no-fake it takes more time until the light will be distributed there.
I used PMC for both, just some few minutes.
The properties of the material i can tell you later, when i am back home.

Re: Glass LED light

Posted: Mon Mar 11, 2013 2:28 pm
by clausgs
HI

thanks for the info...
Yes pleas try to share your material settings,,, thanks in advance,,,,as i understand it you have created 2 glass materials, one for the main glass shelf surfaces and another material for the outer surfaces of the glass shelf,,, correct??

Do you think it it will work with AO??

Thanks
Claus

Re: Glass LED light

Posted: Tue Mar 12, 2013 2:46 am
by clausgs
HI

made some tests and got the effect more or less like i want with the fake version.
I tried to make both specular and glossy material for the shelf and glass door it seams there is not too much difference.
Lots of noise in both renders???
Also the glass door in front of the cabinet have lost it's edges???

AO
sample 2000
render time about 2:45 min
Brg.
Claus

Re: Glass LED light

Posted: Tue Mar 12, 2013 9:26 pm
by Andreas.visjon
Hi Claus,

i think u will need PMC, at least PathTracing.
,as i understand it you have created 2 glass materials, one for the main glass shelf surfaces and another material for the outer surfaces of the glass shelf,,, correct??
See the screenshot of the max viewport i have uploaded, in the top view u see the blue glas shelf (with just a clear glass material) and the yellow one, with the "special" material.

Because Octane is a physically based renderer, the nofake version works like in real, some disturbing elements inside the glas will scatter the light. For the quick test i used a specular material, clear glas with index 1,4 and turbulence texture as bump for the outer frame.

In the fake version i used the same, but without bump, instead a scattering medium map with blackbody emmission.

Looking forward to see your progress.

Ciao
Andreas