Planetside Software Forums

Some very interesting looking possibilities here. Looking forward to your additional work here.

These are interesting exercises. I have not had this kind if effect using this. Nice work.

All these are on the flat default terrain. It would be more fun perhaps to try this on various slope structures. Still, the effects on the plane are quite cool looking. Are you using a node group to influence the way the erosion occurs?

Quote from: njeneb on January 27, 2010, 06:13:27 PM
All these are on the flat default terrain. It would be more fun perhaps to try this on various slope structures. Still, the effects on the plane are quite cool looking. Are you using a node group to influence the way the erosion occurs?

The Difference (Erosion Field) is what flattens the terrain. I am not using a node group for the influence of the erosion. Eroded Heightfield will be next after Difference (Erosion Field).

I do not have enough time to finish the rest so if anyone wants to continue to explore the Heightfield Erosion Operators, then by all means please do. Here are the files.

Lastly i leave off an example of three different types of combined GeoControl 2 erosion applied to a Rigid Perlin fractal from Terragen 2 with no fractal details added.

Hmmmm... i somehow get the impression that this is not important at all.

it is important and we don't see a lot of erosion comparaison jobs in here ^^

Oh yes it is :)

I think everyone is always busy researching their own projects. I know I am; but seeing stuff like this is very useful. In time to come I'll remember some thing from a past post like this and find its exactly what I was looking for for my current project.

The last image looks particularly usefull. Looks like rivers to me :) Your using hight fields as your basis, something I almost never do, but I can see the value of working this way.

Keep it up

:)

Richard

Alright, so i gather that you all are aware of the importance behind the realism as i now figured so i will honestly say i am encouraged to try my best to finish the tests. I'd do fully completed projects myself, however i have a very old PC and that in effect makes things hard to complete no matter what i am doing but i can do these tests.

The last image with the GeoControl erosion is a thin flows sediment i think. It cuts fluvial channels in a very realistic manner.

I think i will try and see if there is a way to use the Terragen Erosion Operations and see if it may be possible to get the deep cut channels as well without having to export the height field itself. The Alpine Fractal may be of some use as well.

yes please, continue your research, and sorry if you felt a bit alone with us reading and not responding ^^
cheers !

No worries.    ;)

The default settings produce quite old, heavily eroded terrain where valleys slump to produce larger erosion patterns. To create thin channels you can reduce the diffusion parameter. Increasing flow distance while reducing duration might also give results more like the GC thin flows if your terrain is quite large. However I concentrated more on long term erosion effects that simulate a mixture of short bouts of heavy erosion with long term subtle erosion (and anything in between), and that mixture can't be controlled directly.

"Difference (Erosion Field)" mode is intended for use as a subtle displacement which you might apply to a procedural landscape, so that you can keep the procedural details while calculating the erosion on a heightfield generated from that same procedural. To do that you would want to disable "flatten first" on the heightfield shader so that its displacement is additive.

Alright, Matt. I took your suggestions and i must add i am impressed with the results. Added to a Perlin Rigid fractal. There is a lot of variations of erosion going on both on a large-scale basis and small-scale. There are large cuts and tiny winding cuts, nice sedimentary deposits, even inverted flows and other shifts. This is a very nice erosion algorithm overall.

CCC, that last image is very nice. For some reason this is a part of TG2 we don't hear a lot about. Glad to see someone taking the time to look into it.

Oh now that's what I'm more interested in :)

Looks great - looks very WM2.  What size hightfield was it, and how long did it take to calc (roughly)?

Quote from: reck on February 02, 2010, 04:02:25 AM
CCC, that last image is very nice. For some reason this is a part of TG2 we don't hear a lot about. Glad to see someone taking the time to look into it.

Indeed.

Quote from: EoinArmstrong on February 02, 2010, 04:12:38 AM
Oh now that's what I'm more interested in :)

Looks great - looks very WM2.  What size hightfield was it, and how long did it take to calc (roughly)?

I just used the default 1000 by 1000 pixels/10,000 by 10,000 meters size for this one. Erosion on my Pentium 4 took less then ten minutes to calculate.

Very interesting experiments!

Very interesting! Thanks for putting effort into exploring this territory.
I really like the last test you made. Like Eoin said it looks very similar to WM2, which is good.
The calculation time isn't bad either!

Cheers,
Martin

I will now be creating a preset collection of Erosions at NWDA. It will be some time as to the complex depth i will be going into investigating these features, however once the collections are done, there will be an opportunity for users to add eroded types of terrains to there local scenes.

Stand by!

Quote from: CCC on February 02, 2010, 07:57:34 PM
I will now be creating a preset collection of Erosions at NWDA. It will be some time as to the complex depth i will be going into investigating these features, however once the collections are done, there will be an opportunity for users to add eroded types of terrains to there local scenes.

Stand by!

Thank you; and, we'll be looking forward.

 :o That last one looks awesome! Add some textures, some trees, and some clouds and you have the makings of quite a realistic scene. THank you for the hard work you've put into this, the results are awesome!

Quote from: darthvader1 on February 03, 2010, 01:53:50 AM
:o That last one looks awesome! Add some textures, some trees, and some clouds and you have the makings of quite a realistic scene. THank you for the hard work you've put into this, the results are awesome!

Speaking about masking:

In theory you should be able to generate color from the erosion. I'm just thinking out loud here, so I might be mistaken on how to do it exactly, but I believe you can. If you load the terrain twice in seperate heightfields you could use the eroded one for your scene.
I'm not sure if the heightfield-shader can generate color. If so, then you could subtract the eroded heightfield from the original and use the subtracted color as a mask for the eroded parts of the terrain.
Very nice idea btw of making a pack of different erosion-patterns. If you could get my idea described above get to work it would be really awesome :)

Cheers,
Martin

These new tests look very promising. I really think the last render looks great. Generally I used simple power fractals to simulate erosion with the y axis stretched. Various scales provide the variation of older an newer erosion. But I don't go too far, my Pentium 4 bogs down when heavy calculations are needed.

With my limited testing of the erosion operator, it seems to be only single-threaded. It would be awesome if it could be multi-threaded.

Also, the advice Matt gave is very useful. Does advice like this also apply to the Alpine fractal, which seems to be simulating erosion? If so, it might be nice to have a few typical examples of specific sets of settings.

@CCC - just to be clear, in the last example, are you applying the "Difference (Erosion Field)" to a Heightfield Generate with Perlin Ridges?