Gravel road

[sboerner]

Not very exciting perhaps but essential for the scenes that I'm working on. An all-procedural road is something I wouldn't have attempted just a few months ago – I would have used hand-painted displacements – but I've been investing more time in Terragen and things are beginning to click.

The subject is a dry hard-packed gravel road, well used but well maintained. Basic displacements. No color or underlying terrain. Comments, criticisms and (most of all) suggestions welcome.

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[WAS]

It's a pretty interesting concept. I like the ditches and surface, but i notice that the way it's setup, you can't easily redirect it to create a road path procedurally. The ditches will begin stretching oddly even before you get bends in the road, additionally the high-level displacement in the shaders section is erroneous/not-standard and interferes with also redirecting the road.

I found a good base for roads is to drive them with SSS masks. One day if there is dynamic vector input for positions that can become highly dynamic.

Update: Figure out the issue i was having, works well! Turns out I was missing a warp on a SSS

[sboerner]

Thanks, Jordan, for the response and constructive criticism. Gave me a couple of ideas to try.

I moved all of the displacements above the Compute Terrain node and removed the redundant surface layers. Everything is now pure displacement above the transform and warp nodes, so the roadbed, ditches and surface displacements all stay together as the road is transformed and warped.

I've deleted the original .tgd file and attached the new one here. Again, comments and criticisms welcome.

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[Dune]

I've got no problem with this; looks good and workable. But you can also do this (perhaps a bit simpler) by using one base SSS for road, ditches and center, just by starting out with a very soft SSS, and adding, multiplying or subtracting adjusted masks from this base for the different regions. Furthermore, I would do this after compute terrain (if you even need one), as displacements are quite minimal.
I have a road setup somewhere on the forum, btw. but can't find it atm.

[sboerner]

Thanks, Ulco. When you say "very soft SSS," do you mean by adjusting the edge width and profile, as I have done here? Or is there another way to blur or soften the edges of a simple shape?

At the moment I'm struggling to find a clean way to smooth out any underlying terrain displacements. But it's getting very late here so maybe the answer will be apparent tomorrow with a fresh start.

[WAS]

Thanks, Ulco. When you say "very soft SSS," do you mean by adjusting the edge width and profile, as I have done here? Or is there another way to blur or soften the edges of a simple shape?

At the moment I'm struggling to find a clean way to smooth out any underlying terrain displacements. But it's getting very late here so maybe the answer will be apparent tomorrow with a fresh start.

I think he just means very soft, like 100 "Percent" so that way you can step between soft edges and hard edges by manipulating the base SSS shader.

[Dune]

I'll put something in file sharing. Can't find my earlier setup, so I fixed a new one.

[sboerner]

Yes, I understand now. I'm not sure why I wasn't able to visualize this before – I was stuck on the idea that three SS shaders were needed to control the inner and outer slopes of the ditches. One works fine. Thanks for showing how that works.

I added a clamp node and another constant so the elevation of the central roadbed can be independently tweaked. Later this evening I'll incorporate all this into the main scene and will report back. Should simplify things greatly.

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I'll put something in file sharing. Can't find my earlier setup, so I fixed a new one.

Thanks, Ulco! Appreciate you taking the time to do that.

[sboerner]

New version. As before I'll delete the previous file links. This one incorporates the simplified basic network, but adding controls and a mask increased the complexity again somewhat. But at least it works and overall I'm fairly happy with the result. Still needs shading and testing in a real scene but that will have to wait. I'm going to call this done for now.

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Here is the scene and a clip file in case anyone wants to mess around with it.

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And here is a clip file of my version of WASasquatch's basic network.

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