I am doing a chemistry render but I am struggling with my cupric sulfate solution in a flask in Blender : the Volume Absorption node doesn't really works as expected.

I have a too light area and a thin dark zone (instead of the thick one).

I also have a dark area in the thick glass.


Mesh of the thick glass part with sub surface disabled
Thick Glass in edit mode

Node setups
The colors are light shades of blue, darker ones gave a really dark result.
Node Setups for world and materials

Texture assignment (with normals)
Texture assignment and normals

Light Paths
Light Paths

Color Management
Filmic Log Base Contrast

I think I gave enough information to solve the problem, but feel free to ask me for more. So what am I doing wrong ?

Thanks for your help in advance.

  • $\begingroup$ I believe you are over complicating the problem, I don't think your need all those "interface" materials, a simple Glass and CuSO4 material should suffice for a physically accurate solution. Hard to see in your image, but it seems you also have duplicate surfaces, and inverted pointing normals, the usual setup is generally to suppress the glass surface where the fluid meets it, as far as I know. See blender.stackexchange.com/questions/35726/fluid-in-a-glass $\endgroup$ Commented Mar 4, 2018 at 18:42
  • $\begingroup$ It's a solution yes, but less physically accurate (in real life, the fluid doesn't go through the glass). $\endgroup$
    – Lugrim
    Commented Mar 10, 2018 at 10:21

1 Answer 1


Finally, I tried several things and I got a better result by reworking lighting and trying a new camera angle. I closed the space where my flask is, added windows, added a ceiling, and added a few area lights at the top. I also tweaked my colors and absorption values. I also separated the interface meshes (now, they aren't connected, but still in the same object).

Here is my result


And here is my CuSO4ToAir material (the only difference with the CuSO4ToGlass is the IOR)

CuSO4ToAir node view

I will mark this answer as solution, but I am still listening to a better solution if you have.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .