Refractive Caustics and Affect Shadows

[FlynnAD]

This topic just popped up in the Sketchup forum today, but as a 3dsmax user it seems I cannot reply there:

https://forums.chaosgroup.com/forum/...-pool-caustics

My question caecarvalho is this:

For refractive caustics, if you have to turn OFF the Affect Shadows checkbox within the material, then how do you use the same single material for both things like a plate glass guardrail and a glass marble? To use two different materials depending upon the shape of the object seems senseless.

If Affect Shadows needs to be OFF in order for refractive caustics to show through, that same Affect Shadows OFF means that plate glass will have totally opaque shadows, which is wong (unless all the light truly going through is caustic, which I doubt).

Images and test file attached.

Matt

[Miro]

Seems correct to me. The reason for the shadow on the right box to look opaque is the lighting setup in the scene.
The light with the broader cone has its caustics generation turned off, the other one just doesn't hit that part of the scene to generate enough photons there.

[MANUEL_MOUSIOL]

what do you mean with two different materials now used? did you blend affect shadows on and off in two materials in a blend mtl?

[FlynnAD]

what do you mean with two different materials now used? did you blend affect shadows on and off in two materials in a blend mtl?

The plate glass box to the left and the glass marble have a material with Affect Shadows OFF. The plate glass box to the right has a nearly identical material, but with Affect Shadows ON - this is what I thought was the correct way to make glass.

[MANUEL_MOUSIOL]

Ok. So with the option off you get the bright caustic spot and with it on you don't buy the shadows look right.
But, Miroslav, this can't be right - if we are just looking at the sphere.
i didn't check the scene though, sorry.