Glass, opening a clear window onto the material.
Apologies for the worst post title pun in history, but if you didn’t gather this post is about making glass materials in Unreal Engine 4.
So initial the base material needs to be set to Translucent and the lighting mode to Surface Translucency Volume, these allow translucency to work on the material.
A tint can be added to the material using the base color as usual. 4 basic parameter are then added Metallic, Specular, Roughness and Opacity.
Metallic set at 1 creates a mirror like surface that would be shiny if not translucent.
Specular creates a reflective sheen at when set at 10.
Roughness takes set at 0 keeps the material smooth.
Opacity needs to be set at least around 0.5 to keep it half see through.
a normal map can be added to give a texture to the glass.
And finally a Refraction system can be added to make reflection change with the movement of the viewer. this is setup using a fresnel node and adjusting the falloff to 10 and using that to Lerp between full refraction and less than half refraction around 0.4.
If you wanted to have a pattern over the glass you can apply an opacity map as below.
The image above shows a leaf opacity map applied with a normal map to add texture.
Using these techniques and parameter some really interesting glass materials can be made. One interesting technique is putting a skin inside to simulate thickness, as seen in the beer glass.
Hopeful that helps someone.