View Full Version : Dielectric Artifacts?
02-26-2006, 07:23 AM
I made a simple scene with a galss and green liquid to test out some caustic effect and I am getting a bad artifact in the render that I can not fix. You can see it in the green fluid. Does anyone have any suggestions as to what to try?
it looks to me like the water geometry is intersecting with the glass geom. Try offseting the water surface a bit (use the sculpt tool with a low displacement value and press Flood)
02-26-2006, 09:16 AM
No, it's not correct.
Just delete one surface and set IOR_in 1.333 and IOR_out 1.5 (or your ior for glass and water) for glass surface that contact with water.
ah, so a correct glass geometry would be like this: ?
the black line = dielectric with ior_out = 1 (air) and ior_in = 1.5 (glass)
the gray line = dielectric with ior_out = 1.5 (glass) and ior_in = 1.33 (water)
the red line = dielectric with ior_out = 1 and ior_in = 1.33
is this glass structure correct?
02-26-2006, 11:54 AM
Yes, it's correct.
02-26-2006, 06:09 PM
Yashu - you were right. The geometry was just barely intersecting. The new pic is below. I had originally made the geometry as puppet described but was unhappy with the results so I then made a glass and modeled the liquid inside instead. The picture on the right is using puppets method.
02-26-2006, 09:24 PM
Sorry, what is dielectric?
02-26-2006, 11:35 PM
A dialectric material is a physically correct Mental Ray shader used to simulate glass and liquids.
02-27-2006, 08:17 AM
:) I suppose right image is more correct :) and computed faster.
02-27-2006, 07:45 PM
Puppet - you are right, your method is more physically accurate and end the end looks better. :shrug:
Thanks for the help.
03-02-2006, 06:52 PM
As I remember this effect can be archived in a few step with l-glass.. I mysefl do not like this shader much for buggy thing but the fact It is a good dielectric shader
03-02-2006, 06:52 PM
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