unity-game-engine - 旋转贝塞尔曲线 handle 不起作用

Question

我创建了一条用 handle 绘制的贝塞尔曲线。当我旋转容器游戏对象时，曲线会旋转，但 anchor 和控制点 handle 不会旋转。我怀疑问题出在我的 PathEditor 类中的以下代码行。如何解决此轮换问题？

如有需要，请查看here对于链接到 PathEditor 的其他类，我决定不将它们放在这里以保持问题整洁。

PathEditor Draw() 方法中的可疑行:

for (int i = 0; i < path.NumPoints; i++)
    {
        Vector2 newPos = Handles.FreeMoveHandle(path[i], Quaternion.identity, .1f, Vector2.zero, Handles.CylinderHandleCap);
        if (path[i] != newPos)
        {
            Undo.RecordObject(creator, "Move point");
            path.MovePoint(i, newPos);
        }
    }

路径编辑器:

[CustomEditor(typeof(PathCreator))]
public class PathEditor : Editor {

PathCreator creator;
Path path;

public override void OnInspectorGUI()
{
    base.OnInspectorGUI();
    EditorGUI.BeginChangeCheck();

    bool continuousControlPoints = GUILayout.Toggle(path.isContinuous, "Set Continuous Control Points");
    if (continuousControlPoints != path.isContinuous)
    {
        Undo.RecordObject(creator, "Toggle set continuous controls");
        path.isContinuous = continuousControlPoints;
    }

    if (EditorGUI.EndChangeCheck())
    {
        SceneView.RepaintAll();
    }
}

void OnSceneGUI()
{
    Input();
    Draw();
}

void Input()
 {
    Event guiEvent = Event.current;
    Vector2 mousePos = HandleUtility.GUIPointToWorldRay(guiEvent.mousePosition).origin;

    if (guiEvent.type == EventType.MouseDown && guiEvent.button == 0 && guiEvent.shift)
    {
        Undo.RecordObject(creator, "Add segment");
        path.AddSegment(mousePos);
    }
}

void Draw()
{

     Transform handleTransform = creator.transform;
    Quaternion handleRotation = Tools.pivotRotation == PivotRotation.Local ?
        handleTransform.rotation : Quaternion.identity;

    for (int i = 0; i < path.NumSegments; i++)
    {
        Vector2[] points = path.GetPointsInSegment(i);
        Handles.color = Color.black;

        Vector2 p0 = handleTransform.TransformPoint(points[0]);
        Vector2 p1 = handleTransform.TransformPoint(points[1]);
        Vector2 p2 = handleTransform.TransformPoint(points[2]);
        Vector2 p3 = handleTransform.TransformPoint(points[3]);

        Handles.DrawLine(p1, p0);
        Handles.DrawLine(p2, p3);
        Handles.DrawBezier(p0, p3, p1, p2, Color.green, null, 2);

    }


    Handles.color = Color.red;
    for (int i = 0; i < path.NumPoints; i++)
    {
        Vector2 newPos = Handles.FreeMoveHandle(path[i], Quaternion.identity, .1f, Vector2.zero, Handles.CylinderHandleCap);
        if (path[i] != newPos)
        {
            Undo.RecordObject(creator, "Move point");
            path.MovePoint(i, newPos);
        }
    }
}

void OnEnable()
{
    creator = (PathCreator)target;
    if (creator.path == null)
    {
        creator.CreatePath();
    }
    path = creator.path;
}
}

Answer 1

看起来您正在将点值存储在世界坐标中。当您变换对象时，这些点不会意识到这一点并继续在相同的位置上绘制。

相反，将点存储在局部坐标中并在每次绘制时应用矩阵变换。

编辑执行以下步骤以使其正常工作:

1. 将 Path 中的所有点视为本地坐标(即相对于游戏对象本身)

2. 在 PathEditor 中，只要您想要设置从路径到场景的值，您就应该使用目标的 transform 组件来应用变换。例如，在 Input 方法中，您应该像这样更正鼠标位置:

   mousePos = Creator.transform.InverseTransformPoint(mousePos);

在您的 Draw 方法中，您实际上正在计算正确的 handleTrasform 矩阵和四元数 handleRotation，但您没有应用它们:

Vector2 newPos = Handles.FreeMoveHandle(path[i], Quaternion.identity, .1f, Vector2.zero, Handles.CylinderHandleCap);

应该是:

var pos = handleTransform.InverseTransformPoint(path[i]);
Vector2 newPos = Handles.FreeMoveHandle(pos, handleRotation, .1f, Vector2.zero, Handles.CylinderHandleCap);

您也可以在方法开始时设置 Handles.matrix，比例将自动处理。

Handles.matrix = creator.transform.localToWorldMatrix;