Liquids, physics and colors

, , ,

Sitting on the computer trying to do something productive for the day and craving for a beach, sun and nice beverage is a weird situation to be in. Almost as weird as the results form the exercise. While the objective was not really achieved, the end product is certainly interesting.

Before we confuse you, or you get thirsty the objective was to create a simulation of a few things.

  • Realistic glass material in a new way – a single pass render of Caustics, Refraction, Reflection and Dispersion.
  • Subsurface scattering of liquids with different densities and transparency levels;
  • Make it look good;
  • Learn something;

The idea was to pretty much cheat the physical properties of liquids and accelerate the rendering process of creating images and animations. As usual the tradeoff in such situations is Speed VS Quality. But that does not mean one can not achieve some kind of balance. Lets face it. not all situations and animations need 110% photorealism. Sometimes it just needs to look good and somewhat believable.

This result came out of a relatively simple shader that implements a mix of Glossy & Subsurface material with a twist of calculating the volume so we can apply layers of “thickness” to the material. Notice the top of the Liquid. It almost looks more transparent compared to the lower part. This can also be used to simulate the liquids clarity. Anyone for a glass of pulpy orange juice?

Differences in thickness & transparency and also clarity

So far it kind of looks good. Lets move to the other bullet points.

Glass material needs more work, though this might not be completely possible in a real-time rendering. Some sacrifices may need to be made.
Glass does not usually disperse light too much but it still has some level. May be faking it with a Chromatic aberration shader on the glass layer can help the rendering. Caustics however are still a no go. Even in traditional Ray-Tracing render engines they are heavy to render so they will be on hold for real time… At least for now anyway.

The liquid is actually pretty well if you manage to nudge the viewer that this is some kind of a juice that simply looks that way. It has layers of transparency, clarity and color differences. I`d say it is a success so far.

What we learned:
Cheating physics principles and simulating material properties and regality is really, really hard. Who would have known right.
As always main

Obviously we did not achieve all the goals, but sometimes interesting results come up while playing around with new concepts and methods.

Have some colors to enjoy with full resolution renders bellow :)

May be at some point when we have enough free render time we will post small animation, or it may be a completely separate thing as Liquid simulations is a whole new different process with its own quirks and specifics.

Paint splashes sounds interesting with this material. Soon.