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View Full Version : Natural lens distortion doesn't work with plastic!



andersand
12-07-2011, 11:21 AM
I'm trying to create a an actual lens effect, but no matter what IOR I set my plastic to I just can't get it to distor or enlage a text seen through my lens shaped object....

I've tried with IORs from 1 to 3 and no success.....
Is there a special trick or is it just not possible with plastic?
I thought the renderer was physics based and acrylic and PC are great lenses in real life......


If I on the other hand drop a diamond material on the the model. It works!....even if I adjust the IOR to 1.55 or 1.72 and adjust he thickness down to 0......

JohnG
12-07-2011, 03:43 PM
I think you're going to have to use the glass material with the solid option checked, then you'll get the refraction you want.
The IOR on the plastic material seems to control the level of reflection not refraction although that's not what the manual says should happen so perhaps its a bug.

If you do use solid glass just be aware it will refract the environment NOT the backplate.

Drakenator
12-07-2011, 07:35 PM
Correct. IOR can stand for Index Of Refraction or Incidence Of Reflection (fresnel).

andy
12-07-2011, 08:06 PM
Yup, you'll have to use something with a solid setting checked.

david.randle
12-08-2011, 05:43 AM
I believe the plastic material has the option internally to be solid. (Why its not exposed i'm not sure) I'll try and get an answer from the team...

andy
12-08-2011, 01:00 PM
I'm guessing "solid" doesn't have all the kinks worked out maybe? Why would changing something to solid with No transparency, change the outer reflective value? Maybe that's one of the reasons they haven't moved it to plastic yet? Or maybe that's correct. I can't think of a reason it would be though. As far as I know, solid should only turn on/off internal refraction.
My opinion on that though, I'd rather have internal IOR and external IOR separate instead of just being on/off. For things like a bent window, you might want a hair of refraction to simulate thickness, even if it doesn't have any. So you just move IOR to something like 1.05 for internal and keep external something like 1.6 for accurate reflections. I try and keep anything transparent solid, but you don't always get to do that when you're in a hurry.
I've just been using the general shader for most everything I create myself, only I keep forgetting that if you type in certain fields it up and crashes on you. I'll have to get out of the habit of typing values until you guys release another update. I assume that will be fixed. That one is nice though because it has Most of the available options. It would be nice to have an anisotropic checkbox as well.