Glass can be a giant pain when making realistic interior scenes. Those hours tinkering with sliders are gone, because we have found a simple shader design that trumps all other glass shaders. Boot up Blender and get ready.
For this tutorial I will be using Blender 2.9, but this works for almost all Blender versions.
Let’s start off by adding in a sphere for us to make our shader on. Then we will need some lighting. Load in an HDRI of your choice (get them for free at https://hdrihaven.com/). Now we can start making our shader. Open up a node editor tab and click on ‘use nodes’ to engage the cycles materials nodes. Then you can start by adding in a glass shader. Next add in a mix shader and attach the glass shader to one of the inputs and its output into the material output’s surface input. (Fg. 1)
After that add in a transparent node and connect it to the mix shader’s second input. Now our shader is starting to look remotely like glass. Next add in a ‘light path’ node as well as two math nodes, which are set to add. We can then attach the ‘is shadow ray’ output to the add node and the ‘is diffuse ray’ to the second add node’s input. (Fg. 2)
Now you can attach the one add node’s output to the other add node’s input. Then attach the ‘is glossy ray’ output on the light path node to the input on the second add node. After that connect the output of the second add node to the factor input of the mix shader. Finally, to finish off the effect, add a transparent node to the second shader input on the mix shader. (Fg.3)
And there you have it! A great interior glass shader at your fingertips. This shader is great for windows, but if you want clouded glass or a slightly more visible glass, you can adjust the roughness slider on the glass shader.
I hope this post has been helpful and that you have a lot of fun using this glass shader in your interior renders!
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