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@eelstork
Last active October 12, 2022 02:00
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A C# implementation of aeronautic coordinates for Unity 3D
using UnityEngine;
using System.Collections;
public class Orientation : MonoBehaviour {
Vector3 pitchYawRoll{
get{
return new Vector3(pitch,yaw,roll);
}
set{
transform.rotation = Quaternion.identity;
Vector3 o = transform.position;
transform.RotateAround (o,Vector3.forward,value.z);
transform.RotateAround (o,Vector3.right,value.x);
transform.RotateAround (o,Vector3.up,value.y);
}
}
/**
* Pitch indicates whether a vehicle is pointing up or down.
* It is the angle between the forward vector and the horizontal
* plane.
*/
public float pitch{
get{
float sine = UnaryTrim(transform.forward.y);
return -Mathf.Asin(sine)*Mathf.Rad2Deg;
}
set{ pitchYawRoll = new Vector3(value, yaw, roll); }
}
/**
* Yaw is the angle between the forward vector's ground image
* and the forward/north direction.
* Yaw is the general 'direction' or 'course'.
* if a vehicle is pointing all the way up or down,
* we extract yaw from the right vector.
*/
public float yaw{
get{
Vector3 vector=Ground (transform.forward);
if(vector.magnitude<0.5f){
return EvalAltYaw();
}
float alpha = Vector3.Angle(vector,Vector3.forward);
return vector.x>0?alpha:-alpha;
}
set{ pitchYawRoll = new Vector3(pitch, value, roll); }
}
/**
* Roll is the angle between the right vector and its ground image.
*/
public float roll{
get{
float sine = UnaryTrim (transform.right.y);
return Mathf.Asin(sine)*Mathf.Rad2Deg;
}
set{ pitchYawRoll = new Vector3(pitch, yaw, value); }
}
public float attitude{
get{return pitch;}
set{pitch=value;}
}
public float heading{
get{return yaw;}
set{yaw=value;}
}
public float bank{
get{return roll;}
set{roll=value;}
}
// PRIVATE ---------------------------------------------------------
/**
* Alternatively Yaw can be calculated as the angle
* between the ground projection of the right vector
* and the east/right direction.
* Even if a vehicle is pointing straight up or dawn,
* you can still tell it's course/direction looking at
* position of the wings/tyres.
*/
private float EvalAltYaw(){
Vector3 vector=Ground(transform.right);
float alpha = Vector3.Angle(vector,Vector3.right);
return vector.z<0?alpha:-alpha;
}
private Vector3 Ground(Vector3 u){
u.y=0.0f;
return u;
}
private float UnaryTrim(float w){
if( w > 1.0 ) return 1.0f;
if( w < -1.0 ) return -1.0f;
return w;
}
}
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