Erosion mapping

[Dune]

If you take 2 heightfield shaders, both fed by a heightfield generator (from a fractal or whatever), and one of them with a additional erosion, you can feed the outputs through a set of displacement shader to scalars and subtract these from eachother. Play a little with the settings. Then you have a map of the erosion flowfields, in which you can put snow or rocks.

[archonforest]

That looks very cool...unfortunately no clue what u are saying 
It would be a big deal for u to upload a screenshot if the nodes? Coz like that I can try to learn this nice tech.

[mhaze]

This is something I really must explore.  I like number two.

[fleetwood]

Nice idea and results. I have to try it. I like Terragen's erosion, but still just scratching the surface (I like bad puns too)

[mhaze]

Works!!!!

[Dune]

See, it's simple (nothing personal, Mick  ).

Here you go, the basics. The merge shaders act as masks.

[archonforest]

Thx for the screenshot. Now I will try to understand the method u wrote before. 

[mhaze]

My method though using the same idea is totally different.  But I think it can be simplified.

[bigben]

Stop distracting me

This is a version of the input-A merge shader.

A few notes.
* For masks, there's no need to convert scalars to colours
* Every mask needs a colour adjust node (also comes with a clamp 0-1 built in)

In this example to colour adjust node lets you scale the differences in values down to a 1-0 range, eg. to provide a gradation for a 10m difference in displacement, black=0, white=10... tweak the gamma to shift the bias towards black or white, and clamp to 0-1

[Dune]

I also had a color adjust shader for finer adjustment, but prefer a merge shader instead of a subtract, as you can play with the amount of difference/subtract for interesting effects.

[bobbystahr]

Brilliant...need more time for testing but music is demanding lately...thanx Dune et al for all the ideas

[dandelO]

An Intersect Underlying, (which could also be positively offset some), with a large enough Patch Size(in a secondary node chain coming off the original terrain), helps with filling erosion channels, works great on the Alpine Fractal. That can then be merged(Raise/Add) with your regular Compute Terrain network, without much added render time at all. Played a lot with that recently for snow build-up and realised it looked very much like eroding the terrain...

*That's with just one terrain node, rather than two. ^^

[Dune]

Interesting. I realize this is probably all unneccessary work, regarding the upcoming (?) erosion plugin  But nice playing anyway.

[choronr]

Thanks for these great ideas. Must do some experimenting.

[bobbystahr]

Interesting. I realize this is probably all unneccessary work, regarding the upcoming (?) erosion plugin  But nice playing anyway.

always good to have new tools/techniques in the tool box...that is what this forum excels in supplying.