Generating Terrain from Heightmaps

If any of the axis get flipped. it's likely a result of how Unity reads the pixels from the heightmap image. Can you just flip the original image?

I'm not quite clear on your question. But the Y axis, can be SCALED. simply adjust the scale.y value in the editor. (scale less than 1 so make it flatter, scale greater than 1 to make it steeper/taller).

This is how it would look with the image you have supplied. Look at the image : it has blocky areas of the same colour (it probably only has a maximum palette of 8 colours); you can see the borders clearly between each colour.

You need a better heightmap image :(

Edit: I have a terrain from Heightmaps : how exactly are you generating the terrain from heightmap?

origin.jpg and generation-terrain-from-row.jpg A comparison of the two images can be inverted to ensure that the y-axis . Would like to know the cause.