This guide will walk you through the process of creating a realistic looking glass in HL: Alyx that will break when you shoot at it. Pieces will fall off as you further interact with the broken glass. It will take 5 minutes to create.
How to Create Breakable Glass with func_shatterglass
How to create the glassTo create a functional breakable glass you need to follow two simple steps. First creating the surface where the glass will live on the map and then creating the entity that controls the glass settings.
To create the surface, select the Block Tool (Shift+B) and in Geometry Type select Quad. This is extremely important. The glass will only work if your surface is ONE FACE. If you create a block (6 faces) the glass will not work.
Set the surface in the position that you would like your glass to be.
Select your surface and under Object Properties click “Tie Selected Meshes to Entity”. It will set your quad as a child of an entity with the Class trigger_multiple. Click on the class name and change it to func_shatterglass. The Object Properties will change and you’ll be able to set properties such as glass thickness, if it should have a frame or if the surface is glass or concrete.