3D World

ARTIST Q&A

your CG problems solved

ASSign cOrrEct iOr tO yOur MAtEriAlS

This is an example of what different IOR values can do, even though all the spheres share the same material, colour and

transparency distance (left to right): 1.001, 1.334, 2, 3, 5. If you are unsure what values to apply to your model, simply look

up the IOR charts online.

ExpErt tip

01

MOdEl thE glASS

Here we have a basic two-part model of a glass and a liquid

inside. We have to break it down into three shells in order to assign

correct materials. My shaky-hand outlines point out the areas we

need to create: a glass, water touching the glass, and water-air

surface. It is important that even though we will end up with three

separate tools, there must be no gap between them.

02

SEpArAtE pArtS

For this process, I used Live Boolean to make sure my water

part fits perfectly in the glass. Notice that the inside of the glass

does not have any faces where the water will be. Double surface

is not cost-effective and would not render well. I used polygroups

created with boolean to delete unwanted surfaces. The same

process can be used to separate the water-air surface.

03

indEx Of rEfrActiOn

Import the model in KeyShot, and drop the Solid Glass

material onto the glass model. Assign the Liquid Water material to

the water/glass part, and up transparency to 5. Open the Advanced

section and set the Refractive Index Outside to 1.5. Apply the same

material to the water-air surface, but leave the RI Outside at 1.

04

lighting SEttingS

This quick render has an HDRI environment set for reflections

only. In the Lighting tab, set the Shadow Quality to 3 and turn Self

Shadows on. Up the Ray Bounces to somewhere between 10-20,

turn on Ground Illumination and activate Caustics (optional). Play

with the settings to see what works in your scene.

StEp by StEp reNDer reAliSTiC liqUiD