Newbie ATTEMPTING total internal reflection

[rhibee]

Hey guys!

Okay, havent used indigo for a loooong time so im back to the basics...

Basically im trying to get an effect similar to the way fiber optics work but with a much wider "wire" if you will. I hope the images below can describe it better for me!

Before render. The "pole" is going through the wall and im hoping for it to transfer the daylight form outside.

But the light doesnt seem to diffuse very strongly, and the glass is almost invisible.

Any help would be amazing!!

Thanks!

[CTZn]

Hi rhibee

Are you using some scatering material ?

Using an ideal optic fiber in vacuum one wouldn't se light wiithin because photons would entirely be reflected to the other hand and run away unstopped. You need some scattering either within the tube or the room or both. Besides, you mat need a longer tube in order for TIR to take place efficiently (greater length/radius ratio).

See those two to get the idea:

http://www.indigorenderer.com/materials/materials/121
http://www.indigorenderer.com/materials/materials/125

You'll have to change the IOR for the conductor. In both cases you can set absorbtion to zero just to get the effect.

[rhibee]

Hi, thanks for the reply!

Im really sorry about this but could you explain in MEGA simple terms please? im completely new to glass rendering that isnt a window

would turning on the fog in sketchup work as a scattering material?

and how on earth do i set the absorption to 0? all i can find is a colour chart... do you mean set the rgb settings for the absorption to black?

Sorry if i sound a lil frustrated, im currently trying to also figure out why my glass is suddenly black :/ normals all facing outwards, glass has volume, is a single entity; even used a preset glass texture and still not working

not a good day im 'fraid!!

[rhibee]

PS

The image above is using the setting "thin glass" for the glass tube. if I set it to anything such as specular with transparency its even WORSE....

[fused]

PS

The image above is using the setting "thin glass" for the glass tube. if I set it to anything such as specular with transparency its even WORSE....

the "thin glass" does not do TIR, you need to use a specular material with a medium.

[fused]

Also, in this scene you might want to use MLT.

[rhibee]

ah okay then ill try and have another fiddle around with specular materials. Thanks :]

MLT doesnt seem to be a help though... just get this

Yuk!

[fused]

I made a scene like yours and only Bidir seems to work best.

Here is my result (very quick render):

pretty cool effect!

What I can tell you from my experience with it:

- make sure the walls have a thickness, otherwise light will leak in.
- use a specular material with ior ~1.6, do not use absorption (leave default setting, which should be no absorption)
- use bidir (maybe with MLT)

And thats about it

[fused]

Also, the faces of the tube and the faces of the wall shouldnt overlap. Make sure your actual tube has a little bit smaller radius than the one used for cutting the hole into the wall

[rhibee]

Its working!!!! I dont know what it was but a combination of all of those worked Thankyou so so much guys!! ^.^