This evening I opened a file I had created yesterday and found half of my earth missing and the other half completely changed. I know I saved the file because the clover population in the foreground is the last thing I added and that is still present in the file (although it has no ground to grow on).
The foreground was a heightfield with a clip vertical applied. The clip vertical gave a flat place to stand and the receding ground gave a place for the lake. The background terrain is just a power fractal with a distance shader.
At first I thought well maybe I need to hit "Generate Now" again on the heightfield. But that didn't do it. Even if it did my power fractal landscape changed as well. If I didn't set something up right from the beginning and can't save this file, so be it. But please let me know what to avoid in the future.
Thanks, in advance.
A backup file (.tgd_bak) may have been created when you last saved. If you can find that file it might be worth seeing if that has the right terrain.
It could be that you changed some of the parameters in the Heightfield Generate node without regenerating (before you saved), which would mean there's now no record of what the parameters were when it was last generated. I've just loaded your file and tried a few things. The mountain on the far side of the lake looks correct after regenerating the heightfield, but only because the heightfield is clipped at 400 and this was also happening with your other heightfield settings. I wasn't able to reconstruct the foreground.
Bummer, thanks for taking a look. At least I've learned to be very careful about unknowingly tweaking heightfields.
I had this once too:
I couldn't render an image at huge size in reasonable time so FrankB helped me out offering to render it. I packed it all up and he returned the render with a different shore as well.
It seemed I accidentially moved the heightfieldshader in the 3D preview, just by 10m, which you can't see by looking at the boundary box.
Therefore I requested in another topic to be able to disable the boundary box of the heightfield, in order to prevent this stuff.
It happens easily because you have to use mouse-buttons to navigate in the 3D preview.