Sorry again for my post… but i really dont get why it seems I'm doing something really special while i'm not.. and I dont get any result or solutions.

Shadows trought Glass or just transparent objects.

brand new scene.
I've a grid GEO as a floor (with a plastic or anything else material).
a Box GEO as a glass (with VEx glass, or Vex Supermaterial)..
a Cone Light as a light (with or without shaders)..
that's it. I just have plain black shadow.

shadows are plain Black. the Box has been shaded with SuperMaterial, VEX Glass, no way to get shadows properly casted as I'd expect. When I color the transparency I should get Colored Shadows, aint it?… no way.. plain black shadows.

It takes longer to explain my problem that really figure it out.. i just cant get correct shadow from transparent objects .. i tried all glassy shaders from Houdini otl (vex glass, supermaterial) and all type of shadows shaders for the light, shop and no-shopped…
what i might be stuck with is the Mantra Ray sampling maybe.. which i'm not familiar yet (i'm a really newbie).

please, can anybody guide me trought this simple process?

thanks a lot in advance.

Mantra filtered shadows (and transparency) rely on the Of (opacity) VEX variable to determine the light that passes through a surface. So for colored shadows to work, you'll need to check the following:

- Make sure you are using a shader that sets the Of variable to the desired opacity of the surface.
- Use a shadow shader on the light with filtered shadows (filtershadow uses ray tracing, or in H8 you could alternatively use deep shadow maps).

The default glass shaders set the opacity to 1 to have consistent compositing. If the opacity was set below 1, the whole object would get blended with the background which is usually not desired. So you'll probably need to either write your own glass shader that sets the opacity to some other value, or build one in vops. You could also try the VEX constant surface shader to understand what happens when the opacity is changed.

thanks a lot, that was at least really clearifying to me.. makes totally sense now.

therefore.. this means it's time for me to start write some shaders

anyone have a “Vex coding for noobies?”.

I'll try to write then my first shaders right now that i want that pins_toy rendered out of mantra… and the challenge of writing my own shaders is stimulating me a lot. thanks for your help.

cheers.