Alter vehicle angle to match that of ground

Question

I am trying to align a non physics vehicle to the same angle as the floor, using blueprints in UE4.27

At first, I used normals, but this has undesired effects when going over things like speed bumps.

I have tried LookAtRotation but that only gives pitch and yaw. I only want to get pitch and roll, yaw is controlled by the vehicle.

I have a location I get from a line trace at each corner. I want to compare this to a part on the vehicle (that is perhaps at floor level) to determine what pitch and roll I need to apply to the vehicle to align it to the floor or obstacle I am driving over.

Answer 1

Let's call the four points where your linecasts hit the ground frontLeft, frontRight, backLeft, and backRight.

This lets us find a vector with the amount of forward tilt (pitch) we want as:

forward = frontLeft + frontRight - backLeft - backRight

And the angle it makes with the horizontal plane is:

pitchRadians = asin(forward.z / length(forward))

Similarly for the side-to-side (roll) angle:

right = frontRight + backRight - frontLeft - backLeft
rollRadians = asin(right.z / length(right))

You may need to negate one or both and/or convert from radians to degrees, depending on the details of your coordinate system.