Hi There. Since Vermil told me how to make the engine load the textures, it worked like a charm.
I followed this instructions:
And Everything works great, except for the rain. I did exactly as the instructions says, and in the previous version of Doomsday that I was using (version 1.9.0 beta 5.1) the rain an every 3d model worked. I use the exact same pk3 in version 1.9.10-1 (the latest stable) and everything works great, except for the rain. I remade the steps of the instructions again to make sure nothing goes wrong, but with the same results. I remember the instructions were made a long time before version 1.9.10-1 was released. So, could the problem be that, the version? Or what could it be?