Unity TerrainData not compatible with absolute elevations?

Question

Is it possible for the Unity TerrainData structure to take absolute elevations? I have a terrain generator that generates absolute elevations, but they are huge. The perlin octave with the highest amplitude is the one that decides what altitude the entire map is at, with an amplitude of 2500 and wavelength 10000. In order for my map to tile properly and transition between altitudes seamlessly, I need to be able to use this system of absolute altitude. I would scale down my generator's output to fit in the limited space (between 0 and 1), and stretch the y scale of the TerrainData, but it will lose too much precision.

What can I do? Is there a way I can use elevations that may vary by as much as 2500 meters? One thing that might be important is that there will never be that much variation in the space of a single Terrain object, but across many, many Terrain objects, it is possible for the player to traverse that kind of altitude.

The unity tag is for Microsoft Unity. Don't misuse it. – Lex Li Jul 11 '12 at 12:34 — Lex Li, Jul 11 '12 at 12:34
sorry about that. solved the problem myself... – Miles Jul 12 '12 at 05:09 — Miles, Jul 12 '12 at 05:09

score 0 · Accepted Answer · answered Jul 12 '12 at 05:14

I've tested changing different variables, and I've reached the following conclusion...

Heightmap Resolution does not mean precision of data (some people I asked believed it determined the number of possible height values). It means the number of samples per row and column. This, along with size determines how far apart samples are, and effectively how large the polygons of the terrain are. It's my impression that there is no way to improve precision, although I now know how to increase the height of the terrain object. Instead, since I will never have 2500 meters of elevation difference in the same terrain object, each piece of terrain generated by my generator I will put in a terrain object that is positioned and sized to contain all of the data in that square. The data will also have to be converted so that it will fit, but other than that, I see no drawbacks to this method.

Important note: Resolution must be 2^n + 1 where n is any number. If you provide a different value for resolution, the next permitted value down will be selected (always the one below your choice).

Unity TerrainData not compatible with absolute elevations?

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