Prism - Fast & advanced glass shader for Cycles

by ericedelo in Materials, Shaders, Textures

As most of you know, it is no secret that Cycle's default glass shader severely lacking behind in terms of realistic and advanced rendering features. It produces black shadows and dark spots on various places on the glass, it doesn't support dispersion (color separation on refraction), and anyone who has tried using the built in caustics, knows that it's a time consuming, noise-filled and painful process.

Prism, a Fast and Realistic Glass Power-Up for Cycles

That is the reason why I created Prism, to remove these limitations and even discard their existence, to provide easy-to-use controls and full control of these features. As an artist myself, I want focus on the creative process rather than try to battle noise, artifacts and poor results. That's what Prism is for, to remove all the bothersome and tricky parts of the glass shader and only expose the fun parts, while providing a shader that just works, no fuss! Prism is the beefiest update to Cycles glass shader you can find!

Prism adds a whole set of new realistic features to the glass shader, in addition to noise reducing optimizations and speed-ups,  it adds dispersion, the breakup of colors when refracted. It adds light absorption, which takes the models thickness into account, letting more light through thinner parts. And one of the key features Is that it also adds caustics. Very fast caustics, which also takes dispersion and absorption into account. All of these features are easily tweak-able and  disabled if so is wished.

Features included with Prism:

  • Dispersion (colors are broken up on refraction)
  • Light absorption & glass thickness
  • Super-fast caustics with colors, dispersion & absorption
  • Quick render times
  • Plug-n-play, just add it and render, no fuzz
  • Easy to use, pragmatic and artist oriented controls for:
    • Base color & Absorption color
    •  Index of Refraction (IOR)
    •  Roughness
    • Dispersion Amount
    • Caustic Intensity
    • Absorption Thickness & Density
  • On top of this you will also get all the updates and improvements I make to the shader as I use it throughout my own projects, completely free of charge. Also, feel free to request more features or content that I can add to the kit.

The shader is extremely easy to use and Prism provides simple controls, which lets you build virtually any glass-like material, be it diamonds and gems, water bottles, fluids, lenses, ice and so on

. If you have used the regular glass shader before, you already know Prism. Otherwise the documentation will get you up and running in just minutes. . I suggest that you play around with the settings while trying out different light setups and types. I bet you will love the caustics and the creative effects they allow for.

Last updated on 2016-03-21

Release notes v1.1:

  • Simplified Absorption controls
  • Added a shadows slider to emulate shadows on the caustic projection
  • Corrected small errors
  • Added a documentation .pdf
  • Branched the shader into alternate versions.

Appending the shader-groups

Appending the shader-groups Before you can start using the Prism glass shader, you'll need to extract the blend file and append the node to your project.

To append the desired shader to your project, click on File in Blenders top bar and navigate to Append or click Shift+F1. This will open the file browser for you, where you will need to navigate to the source files.


Select the nodes or presets you wish to import, hold down Shift to select multiple of them or press A to select them all. Then click on Append from Library.

Selecting and appending the node-groups.

Now, while in the Node editor you will be able to select the node modules from the Add (Shift+A) menu, under the Group drop-down.


You can also access them by clicking T in the node editor, which will bring up the Tool Shelf, where they will be located under the Group tab. Make sure you have Cycles selected as the render engine; otherwise they will not show up. You should also be able to find the material presets under the material tab.





Better Normal Glass, Prism Glass, Prism Glass + Absorption

Prism comes with different shaders-groups:

Better Normal Glass:
This is the default Cycles shader, but with a transparent shadow, instead of the default dark one.  This does not include caustics, dispersion or absorption. Use it if your project does not need caustics, dispersion or absorption, but want transparent shadows.

Prism Glass:
This is the core shader, it includes dispersion and dispersion aware caustics including controls for these effects. It renders slightly faster than the absorption variant. Choose this one if your project do not need absorption.

Prism Glass + Absorption:
This shader is the same as Prism Glass with the addition of absorption and absorption controls. It is slightly slower than the Prism Glass shader, if you project do not need absorption, choose the Prism Glass shader instead.



Color controls the overall color of the glass. It accepts a color or an image texture.


Comparison of two different color inputs

Absorption Color

Absorption Color controls the color of the absorption accumulation in the glass. Requires a absorption density value for results to be visible.


Left: A transparent glass color with green absorption color. (Notice the transparent ears)
Right: A green glass color with a red absorption color.


Roughness controls the micro surface roughness of the glass. High roughness values will give more diffuse glass and less sharpness.


Left: No roughness, Right: Roughness increased


IOR (Index of Refraction) controls the amount of refraction to occur in the glass material


Left: IOR: 1.3, Right: 1.65

Dispersion Amount

Dispersion Amount controls the amount of color shifting that will occur upon refraction. This will produce color distortions on refracted surfaces. This will also affect caustic color.


Left: Dispersion set to 0, Right: Dispersion increased

Caustic Intensity

Caustic Intensity controls the brightness and intensity of the projected caustics.


Left: Low Caustic Intensity, Right: High Caustic Intensity

Shadow Strength

Shadow Strength controls the amount of darkness to multiply onto the caustic projection.


Left: Low Shadow Strength, Right: High Shadow Strength

Absorption Density

Absorption Density controls the density of the absorption color. Higher values results in greater absorption color accumulation in the glass


Left: Low Absorption Density, Right: High Absorption Density


Normal allows you to provide a normal for bump or normal mapping.


Left: default normal, Right: bump-mapped normal provided


Support & Contact

I’d love to get your feedback, see the renders of the things you make with Prism, questions, suggestions, feature request and anything in between.

You can ask any questions regarding Prism on the Blender Markets dedicated support page. It’s the support tab on the Prism product page. Or you can always reach out to me on Twitter @ericedelo.

No FAQ's found for this product.

Item Rating

This item has an average rating of 5 from 15 ratings by the community.

  • jeremy 21 days ago

    i can't use it..... i append them but no appears

  • Ľuboš Černák about 2 months ago

    It work how I except - the best for caustics I've ever seen

  • virgil89 3 months ago

    what glass should look like !!

  • Fredrik 3 months ago

    Love this shader! I got an issue thoug, I do not know if it is a bug or not.

    When I change the IOR slider on "Better Normal Glas", nothing happens, nothing changes in the glass at all.

  • Theodor Hilgers 5 months ago

    Very nice add-on for Cycles. Thank you so much.

  • originalnewbee 6 months ago

    Definitely better result than built-in glass shader and anything I've done.
    But, as soon as I try to include mutliple variants on normals, procedural roughness and colored class using this it seems to break... the fix is to do all the colored stuff with vanilla glass and similar...

  • vjaceslavt 7 months ago

    very simple to use and a great add-on for Cycles! Thank you for your Work!

  • ezydenias 8 months ago

    This is so great, looks way more realistic than before. I say, until they redesign the caustics in special as well as the regular glass shader for cycles, this is a must have.

  • Marek Moravec 8 months ago

    This is so much better than the default glass shader! Love it!

  • Milica 10 months ago

    Really pretty! Thank you so much! ^__^

  • giblet about 1 year ago

    Just what I was looking for!

  • Arsen Mikitov about 1 year ago

    Очень круто! Наконец-то нашел! Super!

  • Matthew Stoeckel about 1 year ago

    Excellent and beautiful

  • Claudio Malagrino over 1 year ago

    Very nice add-on for Cycles. Thank you so much.

  • mendenbarr over 1 year ago

    Excellent - highly recommended. Looks many times better than the default Blender glass shader.

Purchase this item to leave a review!