problem glass material with thickness strange reflections

[Anonymous]

hello, i've found a strange problem.

Here is my render :

you can see that there is 3 reflections of the hdri (it does the same with simple area light), that's logical because there is 3 surfaces with specular (the two surfaces of the bottle and the liquid), but what i don't understand is why there is this big offset with the three reflections, normally they're very close because the thickness is little.

so i've tested with simple sphere in 3dsmax (2019 and 2020) and maya 2019.2, i think is a bug of the rendering for 2 transparents surfaces . So there is two sphere, on the left simple sphere without thickness, on the right there is one but with a very litlle thickness. And you can see that the reflections have a big offset, it's not realistic, and even when i set the thickness at 0, there is a big offset like the thickness were very big.Thanks if someone know the solution.

[thiago.ize]

Unfortunately this is a known limitation in Arnold due to our caustics avoidance code.