计算过程如下:

1,通过由主角中心raycast一条竖直射线获得主角所在处地面法线,用作主角的newUp。

注:一定要从主角中心raycast,而不要从player.transform.position,因为如果player的模型原点在脚上,则player.transform.position可能就在地面以下了,向下raycast得不到与地面的交点了就。

2,根据主角forward和newUp计算newForward。

3,使用Quaternion.LookRotation (newForward, newUp)获得主角新的rotation。

结果如图:

unity, 让主角头顶朝向等于地面法线(character align to surface normal)-LMLPHP   unity, 让主角头顶朝向等于地面法线(character align to surface normal)-LMLPHP

代码:

     //note, the code here suppose our character use a capsuleCollider and the floors' layerMask is "floor"..

     //..if yours' is not, you should make some change.

RaycastHit hitInfo;
        Vector3 capsuleColliderCenterInWorldSpace=GetComponent<CapsuleCollider> ().transform.TransformPoint (GetComponent<CapsuleCollider>().center);
        bool isHit=Physics.Raycast (capsuleColliderCenterInWorldSpace,new Vector3(0f,-1f,0f),out hitInfo,100f,LayerMask.GetMask("floor"));

Vector3 forward=GetComponent<Rigidbody>().transform.forward;
       
        Vector3 newUp;
        if (isHit) {
            newUp = hitInfo.normal;
        } else {
            newUp = Vector3.up;
        }

     //limit lean angle (if do not need to limit lean angle, remove the code block below)

     {

       const float maxDegreeFromWorldUp = 45.0f;//lean angle limited to 45 degree
            //clamp newUp to let is not exceed 45 degree from WorldUp(Vector3.up)
            newUp=Vector3.RotateTowards (Vector3.up, newUp, maxDegreeFromWorldUp / 180.0f * Mathf.PI, 0.0f);

     }
        Vector3 left = Vector3.Cross (forward,newUp);//note: unity use left-hand system, and Vector3.Cross obey left-hand rule.
        Vector3 newForward = Vector3.Cross (newUp,left);
        Quaternion oldRotation=GetComponent<Rigidbody>().transform.rotation;
        Quaternion newRotation = Quaternion.LookRotation (newForward, newUp);

     float kSoftness=0.1f;//if do not want softness, change the value to 1.0f
        GetComponent<Rigidbody> ().MoveRotation (Quaternion.Lerp(oldRotation,newRotation,kSoftness));

04-27 00:27