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Blender internal dispersion and caustics effects


Nion has come out with a great tutorial this week on how to create dispersion and caustic effects in Blender. Although the results are not entirely and physically correct, it makes for a great workaround.

Nion writes:

I guess most of the people think dispersion and caustics are not possible to achieve using the internal render engine of Blender 2.5. In my opinion nothing is really impossible - a lot of things are only more complex to set up and/or less physically accurate than with other render engines. Dispersion and caustics are a good example for that.


  1. Didn't watch the tutorial yet, but what I am sure about is - I LOVE IT. Every time someone manages to achieve such results in blender's internal render engine - I'm happy! Let's spread this all over the world: EVERYTHING IS POSSIBLE. It only requires some effort.
    I hate all those unbiased engines where you wait ages and get result you are not happy with, that looks terrible, but everybody's happy, because it is.... "physically correct". C'mon! Who cares?

  2. @joey: I watched the Cinema 4d video and it looks like they "borrowed" a bunch of stuff from blender. Their new features list reads like Blender's feature list: indirect lighting, lens distort (with chroma ab), sss with identical presets, dof which looks remarkable similar to blenders, cycles like realtime preview, mitchell aa filter, tangent shader etc. I think we should send them a copy of the GPL :)

  3. I wouldn't say it's a great workaround but rather a proof of concept. It's not real caustics and you'd never do this for a real project. It's just kind of neat.

  4. Impressive work. I never expected to see caustics so beautiful in the standar blender.
    how you made this quality of caustics and dispersion.
    A tutorial about this are so useful

  5. The new youtube format will not display full screen so it's very blurry. Any way to post this on Vimeo?
    Just thought I'd ask.

  6. @Terry Sorry, but I'm going to stick to one video distribution site. Do you experience those problems only on embedded videos or doesn't it work on youtube directly, either?

  7. I didn't know the internal dispersion could be done with material nodes. A few months back I tried using composite nodes to combine r/g/b of three identical scenes with slightly different refraction to simulate the same effect (a trick borrowed from Jeremy Birn, Digital Lighting and Rendering 2nd ed, page 273.), but it didn't turn out nearly as nice as this. (Not to mention the hassle of managing duplicate scenes.)

    Can't say the caustics method will be much use to me, but it is very creative. Yikes!

  8. @Andrew etc... I think they scammed JoeAlter out of Shave & haircut, from the comments by Alter on, so i wont put it pas them.

    Personally I think it's actually really bad, why should people (if they did) be allowed to lift the hard work done by many to make Blender one of the best tools out there. And just cos its free don't mean you can lift its code.

    I think someone should let Ton know about this. Because you'd be sure if someone done this to autodesk they be jumping all over them.

    Think about the future too... if they did lift it and get away with it, then they'll only keep on doing it. That's not right.

  9. Hi Joey Andrew & others,

    Blender's open source principles also mean to spread and share ideas and innovations. It's a compliment when others pick up what we did. The 3D CG industry always has been quite open and sharing anyway, reason why it has grown so steadily in the past decades.

    Any unconfirmed accusation or suspicion of GPL abuse (or copying our code illegally) we should stay away from too. Most developers in any decent company wouldn't accept that either. I'm sure our colleagues at Maxon will have the same high moral values as we expect from ourselves in this regard!


  10. Awesome! It seems like each week there is something new discovered that Blender can do! This looks realistic, even on the caustics. Nobody is really going to figure out that the two stops are supposed to be closer together anyway...

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