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Let's say I have a 3D model of a truck with frontal glass (semitrans plastic), with an object - driver - behind it.

Now everything glass-wise looks OK as it should except one very important thing: the glass deforming objects behind it is totally unrealistic compared to a real thing (real brick build LEGO model).

enter image description here

I was able to get that deformation right by manipulating several material attributes incl. IOR value which is the main key to that deformation. But as you can see I lost the feel of a glass/semitrans plastic: those glass edges looks now like a cheap thin plastic sheet instead of a glass.

enter image description here

So my question is: is there some way how to correct that IOR deformation afterwards with some other node(s)?

As for some sort of code/blend file example: you can use/create any known simple glass Cycles node material out there as this is not question about exactly reproducing my stuff, but rather to answer if we can somehow correct the IOR deformation of the glass after the correct IOR was applied with the IOR itself being intact so that we do not lost the glass feel, we just want to somehow correct the deformation it produces - hope you do understand what I mean here.

As some of you asked for actual real LEGO bricks comparison, I am posting here also now extremely simple example, just a curved canopy and minifig torso - see for yourself how unrealistic that distortion on "normal looking glass" is (1st image; IOR = 1.49) compared to the real stuff (2nd & 3rd - with flash - real image) and then my attempt (4th image; IOR = 1.09 + other material attributes changes as well accordingly to look at least a bit like a glass as changing only the IOR value was not sufficient enough to achieve what I did...yet I would still go even lower but then it was basically nothing like glass anymore, really) that has corrected that deformation but unfortunately it looks now much less like a glass + most important discovery: with real LEGO brick there is almost no visual deformation whatsoever!!!:

1st angle enter image description here enter image description here enter image description here enter image description here

2nd angle enter image description here enter image description here enter image description here enter image description here

3rd angle enter image description here enter image description here enter image description here enter image description here

BTW I need a Cycles solution, if possible Cycles v1.9 as that is the version I am using (and I cannot update to newer as the program rendering this is not my own, it is a product of 3rd party, and it's simply using that version).

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  • $\begingroup$ You should set correct IOR value for the material. Plastic is actually similar to glass - around 1.5. There are different kinds of plastics and glass and both may have variations in IOR. You can lower it, a bit if that looks more realistic. Then you should deal with the edges separately with volumetric shaders. $\endgroup$
    – Martynas Žiemys
    Commented Oct 27, 2023 at 11:03
  • $\begingroup$ Also are you sure the result is incorrect? It might not look right only because you concentrate on it too much and don't usually notice it in real life. What does your reference look like? $\endgroup$
    – Martynas Žiemys
    Commented Oct 27, 2023 at 11:07
  • $\begingroup$ I am AFOL (older LEGO enthusiast) having huge inventory of real LEGO bricks at hand, so I can recreate anything I do as CGI and compare, and the real life LEGO bricks do not distorting object behind the glass this terrible hard as on the 1st image, they do it the way you see on the 2nd image. If there would be really need for a real life LEGO bricks example I think I can make a picture, although I do not see why that should be significant regarding if I can provide it or not: you simply have to believe me that the 2nd image as for the deformation is correct one, 1st one is totally off. $\endgroup$
    – fafa
    Commented Oct 27, 2023 at 11:27
  • $\begingroup$ Try reading a few hundred questions here and we'll see if you still believe everything people say... :D It might be good to have a picture to compare it to while working for yourself and to post it here so people can help better in any case.Most of us don't have the reference and don't know how it looks. IOR controls refraction, so if you adjust it until refraction looks realistic, you should leave it and work on other issues that still seem unrealistic to you. Edges get darker because of volume absorption, lighter because of volume scattering. $\endgroup$
    – Martynas Žiemys
    Commented Oct 27, 2023 at 11:38
  • $\begingroup$ Regarding image example I'll update/change those for the real thing (it'll be another simple model: just a glass and a minifig); as for the other things: as I already said: t's absolutely unimportant what glass material you use for your test as the question is elsewhere, that is if we can make somehow correction to IOR deformation afterwards, thus you really do not need to see anything as it is irrelevant...well, unless one did not understand the question. :-D Regardless what image I use it'll not change anything slightest in the question which is not made around any specific image. $\endgroup$
    – fafa
    Commented Oct 27, 2023 at 11:44

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