Thanks all for the kind comments.
I am also trying to learn texture painting in Blender. I am trying to add face by face texture to objects adding special effects like grunge or rust or erosion...displacement look
In my lifetime I have probably made a million or so tileable jpgs just for fun, experimenting with filters for my painting programs. I want to try different texture brushes in Blender using noise other than just voronoi....
I thank all of you for enlightening me about normal, specularity, displacement, and color maps.....and how to use in Terragen
The fact that most share files and experiments is wonderful and a valuable means of education for at least one old duck.