I made a CGI model of a dredger-submarine using an .OBJ mesh editor that I wrote. Hereinunder is an image of the sub rendered in Poser, and an image of it rendered in Terragen.
Its bow labels are a sheet of polygons (material "label") placed about 0.1 inches out from the sub's hull. This material has a diffuse color texture map and a transparency texture map.
In Poser the bow label renders correctly, and where it is transparent, it lets the sub's hull's color show through. (But I must set the label's ambience and reflectivity to zero.)
But in Terragen for this material "label" I have tried many combinations of diffuse and translucency and opaqueness values and texture maps, and all that I can get is:-
(1) Label completely invisible and missing.
(2) As seen here, with the intended transparent parts only partly transparent.
(3) As (2) but without the text.
.OBJ file format was designed for an early CGI graphics program called Wavefront, which did not have transparency, so transparency cannot be passed on in an .OBJ file, but I must restore the transparency after the .OBJ object has been loaded into Terragen.