An experiment with Wilbur and Bryce
This is a little experiment I did with building up a terrain. Basically, I started in Wilbur with the default image size(192x192, I think). I used the tesselation tool with a bit of fractal noise to create the initial slope and sketch in the ridgeline. My attempt to create a piedmont and escarpment structure was not altogether successful, but I know what my error was.
I then used fill-basin to correct the drainage, added a bit of noise to roughen up the flat areas that resulted, then refilled. Next, I looked at the river finding texture to make sure that my streams are decently meandery rather than diving straight down. I repeated the noise-fill-river routine till my river structure looked good to me, then I did an incise flow with a high exponent(2/3 to start with) and a fairly high blur. Here I pretty much followed Waldronate's noise-fill-erode tutorial, decreasing the blur and exponent with each step. Before each incise flow step, I made sure to look at the river flows. At this low res river flow is decently quick and it's miserable to fix a big ugly straight segment after burning it in with incise flow. If I see any ugly spots in the river network, I add noise, fill-basins and look again. Rinse and repeat as necessary. I think somewhere in here I played with precipiton erosion, but hey... My memory is not perfect.
At this point I used Simple Resample to increase the size of my image to about 1200x1200. Now things slow down a bit, but if I have a good foundation I shouldn't need more than a few iterations to add a bit of detail. Basically, I just repeated what I did on the smaller image, but less so.
Another resample to 2048. Adding detail here was a bit slow, but it's still a good idea to keep looking at river flow so that things keep looking good.
I created a straight blend of altitude and slope textures using an atlas-type gradient I found in the Fractal terrains folder. I built a terrain in Bryce using the 16-bit png I exported from Wilbur and textured it with the surface texture just mentioned. The result was the cheerfully-colored image on the right. There was a slight conflict between the lighting direction in the texture and in Bryce. This isn't a bad way to bring out some detail if not too extreme and used in moderation.
I decided the detail was a bit weak so I resampled to 4k(4096x4096). Adding detail and erosion at this point was glacial, but still worthwhile(I wanna MacPro!!!), so I only did one iteration.
I used photoshop to create a new texture for Bryce as well as alpha channels to add specularity and reflection to the rivers, some bump height to forest areas, and a higher diffusion value to the icy mountain tops as they tended to go seriously gray. I spent as much time on the texturing as I did on the built-up terrain for a less satisfactory effect. I did like the forest texture, though.
The texture and HF resolution was 4k for the image on the left.
I think I'll be using this technique in the future. Starting with a low res image allowed me to get an attractively-eroded terrain quickly, with only a little bit of erosion added at higher resolutions where the tools get boggy. This was a good compromise between quality and time.
p.s. The best way I've found to iteratively add noise is to add about 5% percentage noise and an absolute magnitude noise of 3-5. The iteration after my first basin fill was more extreme(15%, 12-25). Also, in the left image there is no river coloring, the rivers in the image are altogether the result of reflection effects in the renderer. I'm not altogether convinced that's a good thing. I might multiply in some ps Add Noise on top of the river map I used as an alpha channel for reflection. Hmmm:?:
Grimtooth Mountains from the Ehrlech Fens
In the foreground of the perspective image(SW corner of the map), we see the Ehrlech Fens, home of the dreaded Muck Ogres. In the background we see the Grimtooth Mountains, ruled by the dragon Grimtooth from his lair on top of the great Mount Eisenzahn. The Trollhome Piedmont, at the foot of the mighty Grimtooths, takes its name from the Bloodfoot clan of Hill Trolls, tributary to Grimtooth himself.
This is my continuing experiment with texturing and light erosion thanks to Redrobes. At present, this terrain is only in 1024sq., but is already pretty nice, I think. Now to separate out some more channels, and see how this looks with variable specularity and such!