// Iterates over selected objects, finds nearest vertex or pivot and sets Tools.handleOffset accordingly
private static void UpdateVertexSnappingOffset()
{
Event evt = Event.current;
// If pressing ctrl/cmd key while using vertex snapping,
// then the pivot should be used to snap on vertices
if (EditorGUI.actionKey && !evt.shift)
{
Tools.InvalidateHandlePosition();
Tools.handleOffset = Vector3.zero;
return;
}
Tools.vertexDragging = true;
Vector3 nearestVertex;
Transform[] selection = Selection.GetTransforms(SelectionMode.Deep | SelectionMode.ExcludePrefab | SelectionMode.Editable);
// Make sure we're not ignoring any objects, that other handles may have set to ignore and forgot to reset.
HandleUtility.ignoreRaySnapObjects = null;
Vector3 nearestPivot = FindNearestPivot(selection, evt.mousePosition);
bool foundVertex = HandleUtility.FindNearestVertex(evt.mousePosition, selection, out nearestVertex);
Vector3 near;
// Is nearest vertex closer than nearest pivot?
float distanceToNearestVertex = (HandleUtility.WorldToGUIPoint(nearestVertex) - evt.mousePosition).magnitude;
float distanceToNearestPivot = (HandleUtility.WorldToGUIPoint(nearestPivot) - evt.mousePosition).magnitude;
if (foundVertex && (distanceToNearestVertex < distanceToNearestPivot))
{
near = nearestVertex;
}
else
{
near = nearestPivot;
}
// Important to reset handleOffset before querying handlePosition,
// since handlePosition depends on handleOffset.
Tools.InvalidateHandlePosition();
Tools.handleOffset = Vector3.zero;
Tools.handleOffset = near - Tools.handlePosition;
}