August 22, 2012, 10:32:47 am
Hi Roland, the cylinder should not cast shadows on the inside provided that the polygons face 'inwards' and are single-sided.
I don't know which 3D modelling application you're using, but in most of them there are options to make polygons single-sided. Let us know if we can help.
However, it is not possible to create panorama textures that become increasingly transparent in a smooth/linear fashion. The reason is that Lumion only supports 1-bit alpha channels in textures, so a pixel is either visible (white pixel in the alpha channel) or invisible (black pixel in the alpha channel).
Instead, I would recommend that you replace the entire sky/horizon with an inverted hemisphere object as described in the post that arch_bd wrote about. The custom backgrounds sample scene/models also demonstrate which material settings work best for panorama cylinders/hemispheres.
TIP: If you only need to render still images, you could also consider using the Sky alpha map output option to render a mask, so that you can replace the sky manually in Photoshop. However, this doesn't sound like a viable option in your case, since your sky texture also includes horizon objects such as trees etc.
