sunlight reflecting off window glass onto ground

Hey I don’t have ton of experience with materials and shaders, or advanced render settings, and I’m having trouble finding relevant info on getting control over reflective caustics, in order to recreate some cool lighting effects in architectural rendering, where bright sunlight bounces off the windows of one building and lands on a matte surface like the ground or another building. What is the best way of going about recreating this effect in Cycles, or is it somehow limited in this respect? Please see example image. Thanks!


Cycles is very poor at caustics - you’ll struggle to get that effect with reasonable sample rates.

You’d probably be better off faking it by projecting light through a mask designed to recreate the caustic patterns. You probably wont be able to tell the difference as long as the source of your supposed caustics are out of shot.

Thanks moony! I also just read about Cycles from BlenderGuru that Cons

  • Still young, not completely optimized.
  • Only 2 rendering algorithms, neither suitable for caustics.

Do you know if I can use any other render engines in Blender to get caustics? There are some tutorials about getting nice refractive caustics, combining Yafaray and Cycles. I am wondering about reflective ones.

Loads of render engines are compatible with Blender

Caustics comparrison

Just do what Gleb showed here :wink:
Lighting for Nerds #01: Light Texture or How to Breathe Life into Dull Scene
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