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Fibre Optic test

Posted: Mon Feb 19, 2007 6:52 pm
by pwrdesign
Hey all!

I dont know why, but I wanted to see if I could achieve a realistic Fibre Optics render?

I've made the fibre optics like this:

Image

The coating has a diameter of 1mm. The cladding is about 0.2mm thick

"A fibre optic cable consists of a glass silica core through which light is guided. This is covered with a material with a refractive index of slightly less than the core. This is called the cladding. The refractive index of the cladding need only be around 1% less than the core to achieve the total internal reflection necessary to confine the light to the core"

I've created the core material and the cladding material.
I've simply started with a Dielectric material with nd 1.5 for the core and 1.3 for the cladding for testing... So far it looks pretty bad :)

http://itk.ramboll.se/visualisering/render/fibre.jpg
(this is the path im rendering too, so the result will develop during the night..)

This is a printscreen from studio:

http://itk.ramboll.se/visualisering/render/fibre2.jpg

For the lights im using 3 circular emitters, one red, one blue and one green.

Image

And this is a top view of the scene:

Image

Any ideas about how to succeed with this? :)
Especially I need some help with the materials I think...:)

Posted: Mon Feb 19, 2007 7:07 pm
by Thomas An.
The cladding should not have a bore in it when you model it.
It should be solid and the core should float coaxially in it (so that you do not have any coincident faces along the length of the tube)

Posted: Tue Feb 20, 2007 12:02 am
by hdesbois
I understand that's not a top priority, but all the same I wish this coincident polygon issue will be dealt with some day.
HD.

Posted: Tue Feb 20, 2007 12:48 am
by rusteberg
well, you've definately found a sucessful solution to rendering the milky way!!! dont give up on it now.

Posted: Tue Feb 20, 2007 8:38 am
by pwrdesign
Thomas An. wrote:The cladding should not have a bore in it when you model it.
It should be solid and the core should float coaxially in it (so that you do not have any coincident faces along the length of the tube)
aaah, ill give that a try!

Posted: Tue Feb 20, 2007 9:43 am
by pwrdesign
New try!
New model!

Image

Image

same materials as before...

Milkyway is fun but.. :)

Image

Posted: Wed Feb 21, 2007 5:45 pm
by lebbeus
maybe try having a bit of ambient lighting, low so we can still see the effect of the fiber optics--wasn't there a fiber optic render in the gallery of the main site back in the alpha days? I seem to remember that image being a major reason why I bought MW in the first place

Posted: Mon Feb 26, 2007 1:57 am
by Rickyx
There is some problems with the MR gallery... and there is not any more the image you are referring.

You may have a look on this anyway... and there is the same explanation but done with air.
http://www.winosi.onlinehome.de/Gallery_t13.htm

I tryed with MR and it was ok.

Posted: Mon Feb 26, 2007 2:26 am
by deadalvs
the radius of the pipe determines the amount/number of internal reflections, maybe just start with a much simpler version of the test...

this is nearly impossible with maxwell with this geometry... sadly.

* * *

cool test though !

Posted: Mon Feb 26, 2007 6:12 pm
by Mr Whippy
Well I think this looks pretty good.

As above (pretty much) just with a matte light tube to get close to parallel light (well close, also some leakage because my core extends beyond the cladding) using a red bright lamp (non-real data)

60W 5cmx5cm plane above.

20cm of fibre optic.
1.5mm diameter cladding with just under 0.95mm bore, core 1mm... so 0.05mm overlap so no co-incidents but still a change in mediums which pure overlapping doesn't allow (Nd's as above)


Main thing is co-incident won't work, neither will overlapping through core/cladding, BUT having an overlap AND with a cavity appears to work well :D

Image

Dave

Posted: Fri Mar 16, 2007 8:24 am
by pwrdesign
Thats interesting!

Thanks for your imput!

Posted: Fri Mar 16, 2007 9:16 am
by sandykoufax
Wow, looks very nice, Mr. Whippy. :shock: