Caustics question - z height dependent shadow

[wessexwoad]

Attempting to learn caustics in water. Getting an unexpected shadow line that seems to be dependent on the z height location of the model, meaning as the model is moved below the z-plane the shadows moves to the left covering less of the photon radius. If the model is moved above the z-plane the shadow line moves right covering more of the caustics.

Thanks in advance for any insight.

[wessexwoad]

Sorry, wrong forum. Meant to post to Rhino: Public.

[vlado]

Either way, can you post an image?

Best regards,
Vlado

[wessexwoad]

Image attached.

[vlado]

It looks like the distance from which the photons are shot is too close to the scene; not quite sure that works in Rhino, but you need to move your sun light farther from the model.

Best regards,
Vlado