Help with IOR, refraction, glass

[clown10]

Hi there,

I made a table with a glass plate, made some nice looking glass and everything looks perfect with the exception of the IOR.

The glass has an IOR of 1.6 and the reflections and refractions look perfect, but everything that is beneith the glass is still bended.

In my understanding the IOR works so that the light that goes into the glas is bended according to the IOR value, but the light that goes out of the Plate ( it is a box and not a plane) will be parralel to the incoming rays again, so that I will have no distortion on the back (just within the plate).

I tried everything i could imagine to get rid of the problem, but I still cannot find the magic button.

Is there anybody who knows how to do this.

Because when I set the IOR to 1 the reflection and refractions on the edges are gone.

Please help

[Da_elf]

i do believe glass has an ior of 1.54 or something like thathttp://www.vray.info/entry.asp?entryID=77

[clown10]

yes this is true, but it wont solve the problem. It is the distortion of the underlying objects that is causing the pain.

[flipside]

The underlying objects will shift a little bit if you look at a thin glass plate from an angle.

can you show an image of your problem?

[egz]

Sounds like a geometry problem. Try chamfering the edges of the box to prevent phong smoothing on on the polygons that should look flat.

[clown10]

Thanks for all your help.

It was a geometry problem. I used a chamfer box as the tableplate (as it should be) and with this I had the problem.

When I use a normal box the rays behave correct.

Any idea why the chamfer box causes this problem?

[flipside]

maybe the top and bottom surface were so close to each other that max thought they touched? Did you try more subdivs (more polys)?

[clown10]

I don't think that this was the case since the distance is the same (2 cm) as the normal box.

Concerning the subdivisions, i made the plate with as few as possible.