CreateStare function to Matrix4.cs

[ghost]

I added a function to Matrix4.cs that will let you rotate a vector to look at another vector, like a look at matrix, but not for cameras. I found this useful in my projects, so I was thinking it could be added to the library.

[TheAIBot]

I thought CreateStare and LookAt looked similair so i took at stab at recreating CreateStare from LookAt. Assuming you are rotating a Vector3, then Matrix4.LookAt(eye, target, up).Transpose() is the same as Matrix4.CreateStare(target, eye, up).

I wrote a little example.

static void Main(string[] args)
{
    var eye = new Vector3(7, 2, -3);
    var target = new Vector3(3, -4, -1);
    var up = new Vector3(9, 8, 7);

    var a = Matrix4.LookAt(eye, target, up).Transpose();
    var b = Matrix4.CreateStare(target, eye, up);

    var test = new Vector3(27, 3, -33);
    Console.WriteLine(a * test); //<-27,89182. -19,767666. 25,657078>
    Console.WriteLine(b * test); //<-27,89182. -19,767666. 25,657078>
}

With that in mind, I don't see the new methods as too useful.

[ghost]

I thought CreateStare and LookAt looked similair so i took at stab at recreating CreateStare from LookAt. Assuming you are rotating a Vector3, then Matrix4.LookAt(eye, target, up).Transpose() is the same as Matrix4.CreateStare(target, eye, up).

I wrote a little example.

static void Main(string[] args)
{
  var eye = new Vector3(7, 2, -3);
  var target = new Vector3(3, -4, -1);
  var up = new Vector3(9, 8, 7);

  var a = Matrix4.LookAt(eye, target, up).Transpose();
  var b = Matrix4.CreateStare(target, eye, up);

  var test = new Vector3(27, 3, -33);
  Console.WriteLine(a * test); //<-27,89182. -19,767666. 25,657078>
  Console.WriteLine(b * test); //<-27,89182. -19,767666. 25,657078>
}

With that in mind, I don't see the new methods as too useful.

I just found the function online, and converted it to C#. I didn't know you could just transpose LookAt to do the same thing.

[giawa]

Hey there, thanks for the contribution to the project! It's awesome to see other people using this code. As TheAIBot mentioned, it looks like similar functionality exists by taking the transpose of the LookAt matrix. Is CreateStare a commonly used function (do engines like Unreal, Godot, Unity, etc have similar functionality)? If so, I think it's worth including, but perhaps include it by simply calling LootAt(eye, target, up).Transpose() instead of producing duplicate code. Let me know what you think.

[ghost]

Hey there, thanks for the contribution to the project! It's awesome to see other people using this code. As TheAIBot mentioned, it looks like similar functionality exists by taking the transpose of the LookAt matrix. Is CreateStare a commonly used function (do engines like Unreal, Godot, Unity, etc have similar functionality)? If so, I think it's worth including, but perhaps include it by simply calling LootAt(eye, target, up).Transpose() instead of producing duplicate code. Let me know what you think.

Unity as a LookAt function for objects, and I think Unreal has one also. Yeah, I didn't know it was the same result as LootAt(eye, target, up).Transpose().

[giawa]

Does that mean this PR can be closed for now? I was unable to find examples of a Stare matrix in Unity/Unreal, but that doesn't mean we can't add one.

[ghost]

Does that mean this PR can be closed for now? I was unable to find examples of a Stare matrix in Unity/Unreal, but that doesn't mean we can't add one.

CreateStare would do the same as LookAt for objects in Unity.

[giawa]

Sounds good, closing this as duplicate functionality.