terrainData.GetSteepness() usage

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How is GetSteepness() used? I just noticed, it accepts an x and y, not an x and z. This is confusing me. What z is used if x and y are given.

Also, I've normalized the coordinates based on terrainData.size. For some reason, it returns 1 as the steepness every time, even on sloped hills.

Answer 1

Answer by Eric5h5 · May 20, 2013 at 12:15 AM

A terrain uses 2D data (namely, a heightmap); there is no Z used in the creation of a terrain. It's not relevant. Perhaps it would make more sense to specify X and Z, but in this case X and Y refer to the width and length.

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Answer 2

Answer by ArtOfWarfare · Dec 13, 2015 at 03:55 AM

When using GetSteepness(), you should provide your X and Z values in place of X and Y, and you should normalize them so that they're between 0 and 1. If your X and Z values have the same origin as the terrain but need to be normalized, you can use the following:

 float normalizedX = myX / terrainData.size.x;
 float normalizedY = myZ / terrainData.size.Z;

Now this part isn't documented anywhere, so this is why I really feel compelled to answer this question: GetSteepness() returns a float between 0.0 and 90.0 representing the Euler angle of the slope. This seemed like a bizarre choice to me - I had expected it to be a float between 0.0 and 1.0.

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Bunny83 · Dec 13, 2015 at 01:41 PM 0

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A value between 0 and 1 would actually be bizarre. What would it represent? Still an angle? If it's an angle you would use some kind of angle unit. So either degree (what they did) or radians. If you don't want to get back an angle but the actual slope, the returned value would represent the tangent of the angle and therefore would be in range 0.0 to +inf. A value of 1.0 would be 45°, a value of 2 would be 63.435° and "+inf" would be 90°.

You never represent an actual angle as a value between 0 and 1. That wouldn't make much sense.

ps: It's actually an ordinary angle and has no relation to Euler angles. Eulerangles describe an orientation within some kind of Euclidean space

terrainData.GetSteepness() usage

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