This can be done using a 3ds max feature called “UVW mapping”.
please, check the attached pdf tutorial.
Insert the standard 3ds max cup. (or any cup or jar).
Create a cylinder
Put the cylinder inside the cup to serve as the liquid surface.
Bring a real image for the liquid you want. Here we will use coffee.
Drag and drop the image to the cylinder."
Go to modify panel, then modifier list, and choose "unwrap UVW".
The UVW modifier will be added, and new features can be noticed in the modifying panel.
We will use the selection part.
Choose polygon, then click on the upper surface of the cylinder.
In the projection part, select "planner map"1, then "align to z-axis"2. Look at the following picture.
In the edit UVs part, click on "open UV Editor.."
The Edit UVWs window will appear as shown below.
From the upper "checker pattern list", select the coffee texture.
Then assign the cylinder circular surface to the suitable particular part of the coffee image, as shown below.
And this is all, MISSION ACCOMPLISHED :-)
Adding the materials, effects and lights. We can get a very nice real-like coffee cup.
Thank you for reading my tutorial.
I hope it is useful and clear.