http://www.decarpentier.nl/scape-procedural-extensions
Great article. I found his insight very interesting.
I wonder if Planetside could make any of this code useful for Terragen.
Actually, I thought that the method translates into Terragen 2 very well. I use ridged power fractals with the Y axis stretched to mimic erosion. I never thought about using a blend/distribution shader setup until I read this. Once again something 'clicked'.
Quote from: njeneb on April 03, 2012, 08:05:46 AM
Actually, I thought that the method translates into Terragen 2 very well. I use ridged power fractals with the Y axis stretched to mimic erosion. I never thought about using a blend/distribution shader setup until I read this. Once again something 'clicked'.
I tried that a few times. It does not work for me. I honestly see no difference. Perhaps i am missing something.
Well, short of having an algorithm to create erosion; something like World Machine; this seems to be a way to get an erosion effect.
I have been trying out my interpretation of what the article talks about. I'll post the tgd and a link from here to the file in the file sharing section.
Quote from: njeneb on April 04, 2012, 08:25:11 AM
Well, short of having an algorithm to create erosion; something like World Machine; this seems to be a way to get an erosion effect.
We do have a heightfield erosion operator in TG called Heightfield Erode v3.
Matt
Yes and it is quite versatile but slow compared to world machine and geo control. The faked procedural erosion on the link provides some neat possibilities i think.
True.
Matt
It works well Matt, but the fun part now is to create something that can be used with the Fractal Terrain generator. I think it can be done without the long calculation time required in heightfields. I think by limiting the altitude and slope this can be done.
The difficulty is getting the erosion runnels to blend down slope into the major erosion channels.
This is what I have so far.
http://www.flickr.com/photos/njeneb/6901639986/sizes/o/in/photostream/
It blends two power fractals (ridged and mix 2) using a merge shader. The slope is controlled by a surface layer. If I were just trying to make an interesting rock face, this is good. It is not what I am striving for.
I kind of see a wide faked-erosion left of center. Now the real issue is getting narrow channels and tapering out at the base. :P
I think the only way to do this is by image maps. I was watching Walli's video on importing heightfields into 3Ds and Lightwave. http://www.planetside.co.uk/content/view/58/27/ Slope images can be generated this way.
Tried something else here. The displacements after the fractal terrain node were masked by a low slope angle.
http://www.flickr.com/photos/njeneb/7050672749/sizes/o/in/photostream/
Different view.
http://www.flickr.com/photos/njeneb/6904660606/sizes/o/in/photostream/
The second one looks very nice Henry.
The last images are close to what I had in mind. I think masking by slope will do the trick. I'm going to try using an Alpine fractal in a heightfield.