Blenders default glass shader doesn't meet the required freedom that many 3D-artists crave.
Although there are many solutions, most of them heavily increase render times.
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So I created this lightweight shader, which will give you increased customization to glass materials in comparison to Blenders default glass shader!

Key features

– Dispersion effect, which splits the red, green and blue rays of the light to create a rainbowy gradient from white light
– Bringing back individual controls for the transmission and the reflectance roughness
– Super-fast fake caustics!
– Control the color of the glass accurately! You set the color and the absorption, the shader does the rest!
– Built-in normal-map support

This is a pay-what-you-want product. You can claim the product for free, but I would be more than glad if you decide to leave me one or two Euros. Since I am currently in quite a difficult situation :')

Feature showcase

Dispersion

Dispersion at max setting

Now, what exactly is dispersion? To keep it short, dispersion is what creates that beautiful rainbow effect on glass. It works by combining multiple glass shaders: one for red, one for green, and one for blue. By overlaying them with a slight offset, they blend together to produce the striking rainbow effect, as you can see in the example render.

Color through volume absorption

Have you ever tried to change the color of your glass material and felt that something just looked off? The way it handles the color of the reflection might not seem quite right. To achieve a more realistic and visually appealing result, you can use the volume absorption node. This technique makes the color relative to the density of the model, enhancing the impression of depth. In my shader, you can easily change the color and adjust the “Volume Absorption” value until you achieve the desired result.

Color when using my advanced glass shader

Changing color using Blenders default glass shader

Fake caustics

Have you ever admired the beautiful light patterns thrown on your table through a glass? That’s what refractive caustics are!

Caustics are a challenging topic for rendering engines. Path-tracers like Cycles especially struggle to generate caustics. While there are some workarounds, most are either time-consuming, both in terms of research and rendering, or frustrating to set up correctly. So, why not just fake it? That’s exactly what I did.

While my solution doesn’t provide the most visually stunning fake caustics, I made sure it’s lightweight and easily controllable. Check out the difference in the images below, particularly the shadows cast by the glass objects. As you’ll notice, it works really well on the cylinder but less so on the Suzanne head. This is one of the limitations of fake caustics: it’s nearly impossible to achieve consistent results across all models. My advice is to enable it and then decide if it works for your specific model.

Without Fake-caustics

With fake-caustics

Shader UI

Recommended render settings

To get the most out of your glass-materials, make sure to bump up the value of the “Max Bounces”, for the “Transmission”-Rays, aswell as for the “Glossy”-Rays.

In the renders I have shared in this article, I have used 12 transmission-bounces and 8 Glossy bounces. This way you get rid of those weird completely black spots in your glass materials.

You can find the setting under the render-settings under “Light Paths”.

License

Download the free .blend-file which contains my advanced glass shader and feel free to use it inside any of your projects! Its also free-to-use for commercial-use. If you appreciate my work, it would be awesome if you could tip me!

Get my brand-new Blender pack for 20% OFF using the code "EARLYBIRD", valid until February 16th