/*
* Returns a 3D rotation matrix, over a vector, or a vector through the origin
*/
public static Matrix Get3DRotationMatrix(float alpha, Vector rotationVector, Point translateOver = null)
{
Matrix rotationMatrix = new Matrix(4, 4);
rotationMatrix.MakeIdentityMatrix();
if (translateOver != null)
{
Matrix translation =
GetTranslationMatrix(-translateOver.GetX(), -translateOver.GetY(), -translateOver.GetZ(), true);
translation.Multiply(rotationMatrix);
rotationMatrix = translation;
}
float t1 = GonioFactory.GetArcTrigonometricByRadians(rotationVector.GetZ(), rotationVector.GetX(), Trigonometric.Tangent2);
var yRotation = MatrixFactory.Rotate3DYAxis(t1, true);
yRotation.Multiply(rotationMatrix);
rotationMatrix = yRotation;
float newX = (float)Math.Sqrt(rotationVector.GetX() * rotationVector.GetX() + rotationVector.GetZ() * rotationVector.GetZ());
float t2 = GonioFactory.GetArcTrigonometricByRadians(rotationVector.GetY(), newX, Trigonometric.Tangent2);
var zRotation = MatrixFactory.Rotate3DZAxis(t2, true);
zRotation.Multiply(rotationMatrix);
rotationMatrix = zRotation;
Matrix rotate = MatrixFactory.Rotate3DXAxis(GonioFactory.DegreesToRadians(alpha), false);
rotate.Multiply(rotationMatrix);
rotationMatrix = rotate;
var reverseZRotation = MatrixFactory.Rotate3DZAxis(t2, false);
reverseZRotation.Multiply(rotationMatrix);
rotationMatrix = reverseZRotation;
var reverseYRotation = MatrixFactory.Rotate3DYAxis(t1, false);
reverseYRotation.Multiply(rotationMatrix);
rotationMatrix = reverseYRotation;
if (translateOver != null)
{
Matrix translation = GetTranslationMatrix(translateOver.GetX(), translateOver.GetY(), translateOver.GetZ(), true);
translation.Multiply(rotationMatrix);
rotationMatrix = translation;
}
return(rotationMatrix);
}
/*
* Calculates the scale based on the fieldofview and the near variable
*/
public float GetScale()
{
var rad = GonioFactory.DegreesToRadians(_fieldOfView);
return(_near * GonioFactory.GetTrigonometricByRadians(rad * 0.5f, Trigonometric.Tangent));
}