Some progress, but not quite where I want it. Too hazy maybe, or maybe not hazy in the right places? Still some work to do on the forests and the little town, and I'm not sure about the lighting direction.
As far as Blender goes, I imported RenderCrate-Castles.usd, selected Castle_Large_A in the right-hand pane, then checked the "Limit to Selection Only" in the obj export dialog. That gave me a single building when imported in Terragen, with no texture maps (though the UV's seem to be intact, which is important). I've never had any luck getting textures to automatically map over when converting through Blender, I've usually ended up just assigning the images in Terragen.
My understanding is that in the more recent versions of Terragen (4.5 and up), PBR materials are handled almost entirely through the Default shader. The way I usually map them in the Default shader is:
- Base Color or Albedo > Colour image
- If Roughness map > Roughness image
- or if Gloss map > Roughness image (check Invert box)
- If Metalness map > Metalness image, set Metalness slider to 1
- If Displacement map > Displacement image, adjust displacement multiplier to taste
- If Opacity map > Opacity image
- If Emmisivity map > Luminosity image (not 100% sure on this one)
- AO (ambient occlusion) map > not used in Terragen (Can use as a color function on Default shader to emphasize crevices)
- Normal map > not used in Terragen
- Metallic roughness map > should be split by color channel into separate metallic and roughness maps and then used.
This is complicated by the fact that the PBR workflow in Terragen used to require more nodes, and the
outdated information is the first thing that pops up when you search.
@Kevin Kipper, this would be great for a dedicated section in the documentation, since this question comes up often, and it would be great to have a single point of reference.
Here's a quote from some correspondence I had with Matt last year, "
On the subject of PBR, a lot has changed since that thread. When I wrote in that thread, we had to use a network of shaders. In 4.5 the Default Shader has a number of changes to simplify the PBR workflow, and in many cases it should be possible to do everything within this shader, without resorting to external image map shaders, blend shaders or anything else. The default values have changed and are designed so that you can drop textures into the various slots and it should just work, but you might have to experiment with some of the checkboxes if it looks wrong. I added some remap checkboxes to do things that previously you had to use additional shaders for, and the metallic option removes the need to use the "high IOR" trick to simulate metals. At the same time, the shader maintains backward compatibility with old materials."I'm still not 100% certain I'm doing this right, so if anyone knows more feel free to chime in.
