Thanks for your help Dark Samurai, but I still have doubts about it.

First of all, I've tested this shadow flag (shadow_stencil) but it did not work. I think that this kind of shadow flag doesn't really work to imported object, I mean, it supposes to work just to 3D models created into 3DGS Model Editor. Wht do you think?

In another hand I was wondering if have you an url to download that (softshadowmapping)?

Thanks so much for such help.

RichardGP