I downloaded a few maps that had parts where the soldiers could pass in front of, such as in a tunnel where there is a different color as background. Namely, there is a map called Ants Mk 2 that has this effect, but I can't replicate it. I tried using the "Doesn't collide" option for my polygons, but that just makes it so the soldier passes behind it. PLease, if anyone knows about this, help.

its probably done by using scenery, you can take screenshots of polygons and cut them out, then save them as a .bmp in the scenery-gfx map.

Yes. Doggfather is right. Its done with scenery.

just copy the texture file to your scenery file. i've made some 1338 awakado caves tha way...

Thanks a lot for the fast responses. Now I have the missing element for my new map!