how to Align to collision normal....BUT actually turn around the Y axis unaffected?

Unity Engine
1

Hi,

I have searched forums high and low and I managed to do this in blitz3D via the AlignToVector command but I can’t actually repeat the behaviour in Unity.

Basically, I have mesh hills and a character. It’s semi 2D game from above looking down. The camera does not rotate.

The character should be able to rotate around the Y axis (ie look left and right) however the body should tilt forwards and backwards based on ground angle without messing with what direction he is looking with. Bit like watching a tank go over hills or something.

I got the normal from the collision contact then:

var surfaceRot : Quaternion = Quaternion.FromToRotation (Vector3.up, averageN);	
var newRot : Quaternion = surfaceRot * Quaternion.AngleAxis(transform.rotation.eulerAngles.y, Vector3.up);
meshObj.transform.rotation = Quaternion.Slerp(meshObj.transform.rotation, newRot, 0.2);

However it messes everything up when I try to rotate it on the spot. Any ideas of a better approach?

2

Try this (untested, may or may not get this right off the top of my head):

// I'm assuming 'averageN' is the surface normal.
var surfaceRot : Quaternion = Quaternion.FromToRotation(
    meshObj.transform.up, averageN);
var newRot : Quaternion = surfaceRot * meshObj.transform.rotation;
meshObj.transform.rotation = Quaternion.Slerp(meshObj.transform.rotation, newRot, 0.2);
3

Thank you, that is perfect! :slight_smile: