What's the scale in the terrain and the first person controller?

Hi, I recently working on the terrain height. But, when I set terrain height with 1, it seems lower than the first person controller with scale 1. So, what's the scale in the terrain and the first person controller? It seems 1/2 in fist person controller is near 1 in the terrain. I didn't find any answer about the unit 1 in terrain is how much in the first person controller. I don't know how to make a right scale terrain without knowing how big is it. Please help me, thanksa lot!

Sorry I ask the wrong point I wnat to konw before. More particularly, when I set first person controller A with scale 1, position 0 and another B with the same scale 1 and position 2, the result B is not on the top A, why? Is the position unit 1 seems close to with first person controller with scale 1/2, is this true?

And what means the scale is 1:1:1? For terrain, first person controller, and???

The "Height" value you set in the CharacterController component of the FirstPersonController is given in world coordinates. So if you model your scenes in meters, the default of "2" should be fine. Make sure you don't have any scaling in that GameObject, or any parent object in the hierarchy, they should all read 1/1/1.

How did you "set terrain height with 1"? And do you paint your heightmap, or do you import it from a greyscale/raw image?

You can adjust the world dimensions of your terrain by selecting the terrain and selecting the Menu Terrain->SetResolution... In the window that appears you can change the first three values without losing your heightmap information. These are the dimensions of your terrain in world coordinated. For example, if you set it to 5/5/5, your terrain will cover 5x5 world coordinate units (=meters), and your height map can have any height between 0 and 5, depending on what you painted in it.

Note that if you change the X or Z dimensions of your terrain (changing Y will be fine), any painted textures already on the terrain will not scale with it. So if you change the X and Z from say 10 to 2, all painted textures (both base and detail) will look 5 times as large. So either don't change them after you already painted your terrain colors, or rescale all textures by editing each texture in the "Paint texture" tab of the terrain and adjusting the "TileSize" by the same factor.