C#: Add Basis.LookingAt

This commit is contained in:
Gonçalo Vasconcelos 2023-04-04 23:32:03 +01:00 committed by Gonçalo Vasconcelos
parent 6a65597569
commit b74d4f45bb
2 changed files with 46 additions and 26 deletions

View file

@ -612,6 +612,43 @@ namespace Godot
return b;
}
/// <summary>
/// Creates a <see cref="Basis"/> with a rotation such that the forward
/// axis (-Z) points towards the <paramref name="target"/> position.
/// The up axis (+Y) points as close to the <paramref name="up"/> vector
/// as possible while staying perpendicular to the forward axis.
/// The resulting Basis is orthonormalized.
/// The <paramref name="target"/> and <paramref name="up"/> vectors
/// cannot be zero, and cannot be parallel to each other.
/// </summary>
/// <param name="target">The position to look at.</param>
/// <param name="up">The relative up direction.</param>
/// <returns>The resulting basis matrix.</returns>
public static Basis LookingAt(Vector3 target, Vector3 up)
{
#if DEBUG
if (target.IsZeroApprox())
{
throw new ArgumentException("The vector can't be zero.", nameof(target));
}
if (up.IsZeroApprox())
{
throw new ArgumentException("The vector can't be zero.", nameof(up));
}
#endif
Vector3 column2 = -target.Normalized();
Vector3 column0 = up.Cross(column2);
#if DEBUG
if (column0.IsZeroApprox())
{
throw new ArgumentException("The target vector and up vector can't be parallel to each other.");
}
#endif
column0.Normalize();
Vector3 column1 = column2.Cross(column0);
return new Basis(column0, column1, column2);
}
/// <summary>
/// Returns the orthonormalized version of the basis matrix (useful to
/// call occasionally to avoid rounding errors for orthogonal matrices).

View file

@ -164,14 +164,14 @@ namespace Godot
}
/// <summary>
/// Returns a copy of the transform rotated such that its
/// -Z axis (forward) points towards the <paramref name="target"/> position.
///
/// The transform will first be rotated around the given <paramref name="up"/> vector,
/// and then fully aligned to the <paramref name="target"/> by a further rotation around
/// an axis perpendicular to both the <paramref name="target"/> and <paramref name="up"/> vectors.
///
/// Operations take place in global space.
/// Returns a copy of the transform rotated such that the forward axis (-Z)
/// points towards the <paramref name="target"/> position.
/// The up axis (+Y) points as close to the <paramref name="up"/> vector
/// as possible while staying perpendicular to the forward axis.
/// The resulting transform is orthonormalized.
/// The existing rotation, scale, and skew information from the original transform is discarded.
/// The <paramref name="target"/> and <paramref name="up"/> vectors cannot be zero,
/// cannot be parallel to each other, and are defined in global/parent space.
/// </summary>
/// <param name="target">The object to look at.</param>
/// <param name="up">The relative up direction.</param>
@ -249,24 +249,7 @@ namespace Godot
private void SetLookAt(Vector3 eye, Vector3 target, Vector3 up)
{
// Make rotation matrix
// Z vector
Vector3 column2 = eye - target;
column2.Normalize();
Vector3 column1 = up;
Vector3 column0 = column1.Cross(column2);
// Recompute Y = Z cross X
column1 = column2.Cross(column0);
column0.Normalize();
column1.Normalize();
Basis = new Basis(column0, column1, column2);
Basis = Basis.LookingAt(target - eye, up);
Origin = eye;
}