how to simulate rainbow effect?

[Ros. Riha]

Please, how could I simulate the rainbow effect, that appears as natural lihgt goes through thick sheet of glass and lits neighboring surfaces then by colorful stripes?

[Peter Milner]

Roy may have better guidance, but this is as I understand it.

Create a glass material and under Transparency, set Dispersion and Saturation to 1.0.

Also a high IOR such as 1.6 will help.

[Ros. Riha]

Thanks, tried, but no successtried on simple model - sphere and couple of extruded triangles, rotated differently. Exterior lighting. GroundPlane. ... no colored streaks coming out from glass.

[Roy Hirshkowitz]

Everything Peter said + tag the object as "Caustics".  You'll need to see if it works.  The caustics code doesn't work for all situations, and I'm not sure, in any case, if this (dispersive caustics) was ever fully implemented for the Path Tracer.

[Ros. Riha]

thanks for the tip. Tried out, unsuccesfully. dunno whether it is because actual lighting setup(tried couple of different ones out) or something else. Any further guidance, please?

[Roy Hirshkowitz]

You'll have to post an example.  Start with a picture.  It will help me determine whether we've got a solution for the particular application.

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Somewhere I've got a prism model that I used when designing the effect.