Somewhere in my code, I wrote this:

Vector3 position = new Vector3(0.0f, 0.0f , -3000.0f);
Vector3 forward = Vector3.Forward;
Vector3 up = Vector3.Up;
Matrix.CreateWorld(ref position, ref forward, ref up, out worldMatrix);

The resulting worldMatrix shows that

worldMatrix.Forward.ToString() => {0, 0, 1}
worldMatrix.Up.ToString() => {0, 1, 0}
worldMatrix.Right.ToString() => {-1, 0, 0}
worldMatrix.Translation.ToString() => {0, 0, 0}

Is the implementation right? I'm now very confused with the result because I expected the following result :

worldMatrix.Forward.ToString() => {0, 0, -1}
worldMatrix.Up.ToString() => {0, 1, 0}
worldMatrix.Right.ToString() => {1, 0, 0}
worldMatrix.Translation.ToString() => {0, 0, -3000}

Is this due to my lack of Matrix understanding?

Why don't you use Quaternions, instead of Matrix.CreateWorld?
I think it is much better. And you can use the interpolate functions so you don't need to keep a float to know the rotation angle at the moment.

So you do your world Matrix (which is necessary) like it:
Matrix world=Matrix.CreateScale(myScale)*transforms[mesh.ParentBone.Index]*Matrix.CreateFromQuaternion(myQuaternion)*Matrix.CreateTranslation(myPosition);

(I'm not sure about the Matrix.CreateFromQuaternion function, but there is a Matrix function that does it).

public static void CreateWorld(ref Vector3 position, ref Vector3 forward, ref Vector3 up, out Matrix result)
{
    Vector3 vector = Vector3.Normalize(position - forward);
    Vector3 vector2 = Vector3.Normalize(Vector3.Cross(up, vector));
    Vector3 vector3 = Vector3.Cross(vector, vector2);
    result.M11 = vector2.X;
    result.M12 = vector2.Y;
    result.M13 = vector2.Z;
    result.M21 = vector3.X;
    result.M22 = vector3.Y;
    result.M23 = vector3.Z;
    result.M31 = vector.X;
    result.M32 = vector.Y;
    result.M33 = vector.Z;
    result.M41 = 0f;
    result.M42 = 0f;
    result.M43 = 0f;
    result.M44 = 1f;
    result.M14 = -Vector3.Dot(vector2, position);
    result.M24 = -Vector3.Dot(vector3, position);
    result.M34 = -Vector3.Dot(vector, position);
}

Shawn Hargreaves:

You're right, it looks like the CreateWorld implementation is wrong. Oops, our bad!

Sounds like it's time for a trip to Connect. ;)

No need, Shawn filed a bug.  :)

Unfortunately we won't be able to fix it before we release.

Did you fix the bug in Matrix.CreateWorld implementation?

I dowloaded the new version of XNA Framework 2.0, but it seems that there is still the same problem in the above method.

So, I 've written the implementation myself as it is supposed to be.
Please let me know if my implementation is worng or right.  

public static void CreateWorld(ref Vector3 position, ref Vector3 forward, ref Vecctor3 up, out Matrix result)
        {
            Vector3 right;
            
            // Normalize forward vector
            Vector3.Normalize(ref forward, out forward);
            
            // Calculate right vector 
            Vector3.Cross(ref forward, ref up, out right);
            Vector3.Normalize(ref right, out right);
            
            // Recalculate up vector
            Vector3.Cross(ref right, ref forward, out up);
            Vector3.Normalize(ref up, out up);

            result.M11 = right.X;
            result.M12 = right.Y;
            result.M13 = right.Z;
            
            result.M21 = up.X;
            result.M22 = up.Y;
            result.M23 = up.Z;
            
            result.M31 = -forward.X;
            result.M32 = -forward.Y;
            result.M33 = -forward.Z;

            result.M41 = position.X;
            result.M42 = position.Y;
            result.M43 = position.Z; 
            
            result.M14 = 0.0f;
            result.M24 = 0.0f;
            result.M34 = 0.0f;
            result.M44 = 1.0f;
        }

Thanks in advance.

palbul:

Did you fix the bug in Matrix.CreateWorld implementation?

Mitch Walker:

Unfortunately we won't be able to fix it before we release.

Did'nt you release the final XNA Frmamework 2.0?

I thought that the version, which was downloaded this morning, was the final of the 2.0.

Sorry for that.

Matrix world;
Vector3 position = new Vector3(0.0f, 0.0f, -3000.0f);
Vector3 forward = Vector3.Forward;
Vector3 up = Vector3.Up;
Matrix.CreateWorld(ref position, ref forward, ref up, out world);

Console.WriteLine("Forward: {0}", world.Forward);
Console.WriteLine("Up: {0}", world.Up);
Console.WriteLine("Right: {0}", world.Right);
Console.WriteLine("Translation: {0}", world.Translation);

and the results it yielded:

Forward: {X:0 Y:0 Z:1}
Up: {X:0 Y:1 Z:0}
Right: {X:-1 Y:0 Z:0}
Translation: {X:0 Y:0 Z:0}

So it would seem that the CreateWorld method still does not store the translation data inside of it like it should be.