Merge Sops with different material

I want to merge Sops, that have different colors/materials as well as they are based in different COMPs. But as soon as I merge several of them together in die parent TOP it tells me I cannot us different materials. How can I get around this?
Since I am just starting the geometry I still coundnt find a solution and would be happy for help. Please also see my testfilemerge_Sops.tox (2.3 KB)

The easiest way is to not merge the Sops but to have a geometry for each material. After that you point the render to different geometry to group it.

I actually tried that also, but they dont show up in the render.
geo_Sops.tox (2.3 KB)

You have to move your camera a bit. The geometries are located outside the camera’s current view. To see the 3 circles I had to set the Camera’s tz parameter to 89


ah! ok, thanks.
And I am struggling to make the spheres transparent. I set th the constantMaterial alpha of it, but it only gets darker. I want the objects to be half transparent. I also cannot find any setting in the geo for that. How would this work in TD?

To late for the first answer…
For the second, if you activate blending in the material, the material have transparency