/// <summary>
/// Returns the rotation of an <see cref="Edge"/> in world space.
/// </summary>
/// <param name="mesh">The mesh that edge belongs to.</param>
/// <param name="edge">The edge you want to calculate the rotation for.</param>
/// <returns>The rotation of the edge in world space coordinates.</returns>
public static Quaternion GetEdgeRotation(ProBuilderMesh mesh, Edge edge)
{
if (mesh == null)
{
return(Quaternion.identity);
}
return(GetFaceRotation(mesh, EdgeUtility.GetFace(mesh, edge)));
}
/// <summary>
/// Get a rotation suitable for orienting a handle or gizmo relative to the element selection.
/// </summary>
/// <param name="mesh">The target mesh.</param>
/// <param name="orientation">The type of <see cref="HandleOrientation"/> to calculate.</param>
/// <param name="edges">Edges to consider in the rotation calculations. Only used when
/// <see cref="HandleOrientation"/> is <see cref="HandleOrientation.ActiveElement"/>.</param>
/// <returns>A rotation appropriate to the orientation and element selection.</returns>
public static Quaternion GetEdgeRotation(ProBuilderMesh mesh, HandleOrientation orientation, IEnumerable <Edge> edges)
{
if (mesh == null)
{
return(Quaternion.identity);
}
switch (orientation)
{
case HandleOrientation.ActiveElement:
if (mesh.selectedEdgeCount < 1)
{
goto case HandleOrientation.ActiveObject;
}
// Getting an average of the edge normals isn't very helpful in real world uses, so we just use the
// first selected edge for orientation.
// This function accepts an enumerable because in the future we may want to do something more
// sophisticated, and it's convenient because selections are stored as collections.
var face = EdgeUtility.GetFace(mesh, edges.First());
if (face == null)
{
goto case HandleOrientation.ActiveObject;
}
Normal nrm = Math.NormalTangentBitangent(mesh, face);
if (nrm.normal == Vector3.zero || nrm.bitangent == Vector3.zero)
{
goto case HandleOrientation.ActiveObject;
}
return(mesh.transform.rotation * Quaternion.LookRotation(nrm.normal, nrm.bitangent));
case HandleOrientation.ActiveObject:
return(mesh.transform.rotation);
default:
return(Quaternion.identity);
}
}