Lights through glass?

I think this as been asked before, but could not found anything in the forum.

I’ve made a glass sphere (alpha = 0 , Ray transp >0) .

How do i make a light passing through glass and appear as light (only shadow now) in the plane below the ball?

thank you very much!

Yeah, I want caustics too in Blender. Maybe version 2.5?

Thank you!!

Didn’t know what i as looking for. :expressionless:

select the plane under the glass, go to Shading (F5) buttons and turn on the TraShado button. Now, the shadow of your glass is lighter, proportionnally to the Alpha of the material.

For caustics, there’s none available for now with the internal renderer. If you really need caustics, try to fake them (make a search about faking caustics) or use a caustic-capable renderer like yafray.

More information on RayTransp here:
more up-to-date information here:

Thank you very much!!

I was trying with Raytracing ON with the internal renderer.

I just have to change to Yafray renderer?

sorry if it’s a dummy question.

only if you need caustics… “transparent” shadows are supported by internal blender

The TraShad button means the object under/below/andstuff will receive the transparent shadows cast by the transparent object. So that’s the key. It’s not caustics but it looks more realistic.