(Having trouble posting this thing, I hope I didn't accidentally do a triple post, or worse...)
Hello folks. I'm new to the forums and very new to Terragen 2, only been using it for a few days. I've learned a lot and continue to get better, but there still are things I can't wrap my mind around.
For example masks. At the moment I'm trying to create the island where our RPG adventure is located and I'm having trouble. I have the outline of the island as a black and white 8-bit bmp image (included, though in another format for bandwith reasons), and would like to be able to generate a power fractal terrain and limit it using the image as a mask, so that the world is completely flat, except for the white bits. I've tried to add it as an image map shader (saw it somewhere on the forums, I have been trying to figure this out on my own =), but that gives me really weird results, not to mention taking WAY much longer to render (usually it's done in under two minutes, with this it takes around an hour, at least). I've attached one picture of what happens, taken mid-render. Note that I haven't done anything to the default colors, I have no idea where those black regions on the mountaintops in the render come from. I've been searching through the forums but either I just can't find it or I don't know the terminology well enough to search for the right keywords. Could someone point me to a step-by-step solution or at least give me some pointers, I'm really strugling with this thing?
PS. I've tried alternative ways to accomplish this and I've had limited success using the following procedure:
1. Use the image as a normal heightfield.
2. Add "Adjust vertical" operator to the heightfield and use it to raise the ground up a few hundred meters.
3. Add a power fractal terrain to get some shape.
4. Add a lake node to act as the ocean. Raise it so the coastline is somewhat ok, then fiddle with the displacement offset of the fractal terrain, trying to get rid of the almost inevitable "lakes" that form because the fractal terrain generates values under 0.
With this I run into a few problems. One is that raising the displacement offset often also raises the coastline, which makes adjusting the water level pointless. What I need is a way to force the coastline to stay at a certain predetermined level and everything inland to be above that level. That and I still have no clue how to control where the water is, one of the tutorial did mention that it can be masked so it doesn't appear where you don't want it to.
Second is scaling. Of course I can make it small and just adjust everything accordingly, but if I want to make it 1:1 scale, then we run into problems. The island is quite large, around 500 by 550 km or something like that, and resizing the heightfield to those proportions causes pretty horrific effects, since the heightfield doesn't follow the curvature of the planet. So at least some edges look horrible, usually all.
And lastly (and this is more because of me not knowing how to use the software than anything else) the shape of the terrain. Most of the island is pretty much your average rolling hills and stuff like that. No problem, I can create that easily. This being an RPG-game though there have to be mountains and whatnot in some places. And like I've said before, I have no idea how to control where these appear. I know how to make decent mountains, but how can I limit where they appear? The mountainous areas on the island are marked on the map I'm using as a source, so I can easily trace the outlines and make masks of them, equal in size to the main island mask if necessary. I just don't know how to use the mask to control where the mountains appear.
Oh yeah, I just remembered something. The various villages and towns have already been placed on the map and, unless I'm seriously lucky, most of them will end up in places where no sane human would build a town. How would I go about leveling out some areas of the map so that they'd look at least vaguely habitable?
I'm sorry if this is a bit too much and I've broken every etiquette rule on the forums, but I really have tried to look for what I need and am just unable to find answers or understand them if I do find them. If I can provide other information that will help then please do ask.