Glass

Glass is a material added to Roblox on December 6, 2017. Before glass was added, regular transparent bricks were used, which did not have the effects of glass such as distortion. Glass, along with Neon and ForceField, and unlike other materials, have special effects built in when the Graphics settings are high enough.

Description
Glass is a transparent Roblox material. It can be set with the properties of any other material, such as transparency or color. Glass is mainly used for windows.

When a part's material is set to glass and its transparency is greater than 0, it distorts and slightly blurs the image behind it and becomes less transparent when viewed from an angle.

Trivia

 * Comparisionworkspace.png is the second material to have special effects with the first being Neon.
 * Originally, to save processing power,  did not render behind transparent Glass, which was quickly changed. However, transparent parts still do not render.
 * Water does not render behind glass, and it appears as a different terrain material.
 * Avatar accessories might have issues rendering behind glass if they use alpha channel transparencies.