Road

cyphyr · April 09, 2019, 07:14:04 AM

I'm looking for some help on how to get a road to follow a hilly terrain.
The road is flat (or even gently cambered) in its cross section but should rise and fall along the terrain.

I can make a procedural or image based "map" of the road (or many roads) and add them a displacement along the terrain but they will always take on the shape of the terrain so if the road is going round the side of a hill one side of the road is higher than the other.

I know something along these lines is possible in World Machine and even in Vue with splines but I can't think how to do it in Terragen.

Any ideas greatly appreciated

Dune · April 09, 2019, 01:33:08 PM

I have worked on a solution for this for a long time, and the only thing I came up with is on NWDA. But that's based on a single road (warped SSS) and not on a terrain with roads at your choice, I'm afraid.

cyphyr · April 09, 2019, 04:41:30 PM

Yes I thought of your solution but I don't think it would work with a drawn road on an imported terrain. World machine has a spline option but I don't think even that will work. Back to the drawing board ...

Oshyan · April 09, 2019, 04:50:30 PM

Terragen doesn't have a built-in road or other spline option at present, of course. So I think this is something you'd ideally accomplish in a 3rd party terrain editor and export to Terragen. Would that work? In that case I'd look at any app that has road/spline functions. World Machine does, though I see you have some concerns about whether it will work (what, specifically?). World Creator also has a path tool which may work. But I think my money might be oh Houdini

- Oshyan

cyphyr · April 09, 2019, 07:21:06 PM

Houdini is the best bet I think but that is outside my ken for now. Even then I think there may be some logical problems but I'll leave that for greater minds than mine

Dune · April 10, 2019, 01:53:30 AM

I have an idea, but I have to test if it works

René · April 10, 2019, 05:28:43 AM

How about displacing the road with the same terrain but with a negative value for the terrain.

cyphyr · April 10, 2019, 07:14:15 AM

Quote from: René on April 10, 2019, 05:28:43 AM
How about displacing the road with the same terrain but with a negative value for the terrain.

This actually has some promise, thank you

... It is actually working on an un-modified terrain but if the terrain has masks (controlling valley floor and hight modifications) this seems to not be properly passed through to a final "Displacement shader to scalar" which can then be colour inverted.