Sample Worlds Torn Apart - The 1.1 Default World - Terrain
Check out the terrain next. The texture employs a neat trick to get some real "continents" out of MW. In my admittedly limited experience, the fractals tend to generate some wildly variable terrain with high mountains right next to deep valleys that get filled with ocean water. This produces a rather scattered world with features of the landscape spread more or less evenly about. It would be nice to have some larger land masses and big oceans. The texture named "Continental splat" is a way to do this.
You might consider the splat texture to be a form of mask. Where the fractal value is large, terrain features show up. Where the value is small, things disappear into the sea bottom. If the maximum feature value for this mask is set fairly high, you will see larger continent sized chunks of terrain appear.
If you want to see how this works, it's an interesting exercise to turn the splat values into hills and see where the land masses should show up. To do this,
- turn off the Land height texture by clicking on the little circle to the left of the "t"
- the blend, multiply, is now irrelevant since there's nothing left to multiply with, so you can just leave it alone.
- for the continental texture, extend the kickstand and click on the output control. In the curve editor, change the max output value from 1 to 5000
If you pull the camera out until you can see a good portion of the planet (3 to 4 Million meters up) and do a fast render, you should see large green (flat) continents.
Compare this with a render from the same position with the continental output control restored to normal and land height turned back on.
Land height is not anything new, but the Mountain fractal has a -0.2 for the Zero Offset value. This seems to have shifted the baseline of the fractal up a bit: min/max numbers in the preview show -2000 to 8000 at a 100 km height. A zero setting gives -4000 to 6000. Change the offset to +0.2 and the range changes to -7000 to 4000. Some of these dramatic changes, of course, are caused by the output control, which maps the fractal 0 - 1 output to the range 0 - 3000, but it's interesting to note that a change in offset apparently shifts the "centerline" of the calculations.
The material for the terrain illustrates a nice technique for getting a lot of color variation in altitude. There are 4 color materials: rock, snow, green, and sand.
