Distinguishing 'peaks' from 'valleys' in an almost sine wave scenario?

[1Joeb (joe)]

I need to be able to tell the difference via code whether the area a player is in is a peak or a trough, based on the last surface normal, and current surface normal.

Information I have available:

• Last surface normal
• Last part position
• Current surface normal
• Current part position
• Character velocity ( just in case its useful here… )

Right now I compare the surface normal’s angle relative to directly upward. This was not in anticipation of this problem, it’s just what I already had been doing.

As you can see below, comparing the angles relative to up on both peaks and troughs will yield the same result.

[dthecoolest]

I believe you will need to measure the change of the gradient in a similar manner to differentiation.

How to measure the change of slope? maybe a combination of finding the player’s movement direction in the XZ Plane and the surface normal similar to this thread, multiple raycasts in a line in front of the player.

How to detect and slow/haste a player MOVING up/down a ramp/slope

You can use Ray casting for this. Ray casts return a surface normal vector representing the direction of the slope they hit. This works for circular or ramp objects. You can use this surface normal to find the steepness of a slope. This formula returns the angle in radians between two vectors. Make sure these vectors are both unit vectors. The surface normal is and so should your floor normal. math.acos(a:Dot(b)) Next you’ll want to determine the direction the player is traveling. You can use …

Edit: May we know what the purpose of detecting troughs and peaks is though, maybe there are easier alternatives?

[AstroCode]

For a peak, the vectors would diverge and for a trough they would converge.

To detect that, you could project the 2 vectors onto their shared plane and see if they intersect in front of the vectors or behind them. For example: