WPF - Helix 工具包自动旋转

Question

上周我一直在研究这个问题 - 2 周，但我一直无法找到解决方案。我正在从 STL 文件加载 3D 模型并尝试围绕 1 个轴自动旋转 3D 模型。这个想法类似于缓慢移动的动画，围绕模型的 Y 轴显示 360 度视图。

XAML：

<Grid>
    <StackPanel x:Name="myViewPort">
        <helix:HelixViewport3D x:Name="viewPort3d" ZoomExtentsWhenLoaded="true" RotateAroundMouseDownPoint="true" CameraRotationMode="Turntable" Height="1000" ShowViewCube="false">
            <helix:DefaultLights/>
            <ModelVisual3D x:Name="visualModel"/>
        </helix:HelixViewport3D>
    </StackPanel>
</Grid>

C#：

public void load3dModel()
    {
        StLReader stlReader = new StLReader();
        Model3DGroup MyModel = stlReader.Read(MODEL_PATH);

        /* Auto Rotate Here */

        System.Windows.Media.Media3D.Material mat = MaterialHelper.CreateMaterial(new SolidColorBrush(Color.FromRgb(255, 255, 255)));

        foreach (System.Windows.Media.Media3D.GeometryModel3D geometryModel in MyModel.Children)
        {
            geometryModel.Material = mat;
            geometryModel.BackMaterial = mat;
        }

        visualModel.Content = MyModel;
    }

这方面的棘手部分是我需要能够仅使用代码来旋转模型。生成的模型可以是数百个中的一个，这取决于模型的应用程序......所以代码需要能够处理围绕同一轴旋转，我可以保证何时导出 3D 模型对于 STL 文件，它将沿 X 轴平坦。

--- 更新 --- 通过情节提要尝试旋转：

public void load3dModel()
    {
        StLReader stlReader = new StLReader();
        Model3DGroup MyModel = stlReader.Read(MODEL_PATH);

        System.Windows.Media.Media3D.Material mat = MaterialHelper.CreateMaterial(new SolidColorBrush(Color.FromRgb(255, 255, 255)));

        foreach (System.Windows.Media.Media3D.GeometryModel3D geometryModel in MyModel.Children)
        {
            geometryModel.Material = mat;
            geometryModel.BackMaterial = mat;
        }

        visualModel.Content = MyModel;

        /* Auto Rotate Here */
        GeometryModel3D geoModel = new GeometryModel3D()
        {
            Transform = new RotateTransform3D()
            {
                Rotation = new AxisAngleRotation3D()
                {
                    Axis = new Vector3D(0, 1, 0),
                    Angle = 0
                }
            }
        };

        MyModel.Children.Add(geoModel);

        var Rotation3DAnimation = new Rotation3DAnimation();

        var FromAxis = new AxisAngleRotation3D()
        {
            Axis = new Vector3D(0, 1, 0),
            Angle = 0
        };

        var ToAxis = new AxisAngleRotation3D()
        {
            Axis = new Vector3D(0, 1, 0),
            Angle = 359
        };

        Rotation3DAnimation.From = FromAxis;
        Rotation3DAnimation.To = ToAxis;
        Rotation3DAnimation.Duration = Duration.Forever; //ADDED DURATION, Still did not work!

        var rotateStoryboard = new Storyboard
        {
            Duration = new Timespan(0, 0, 12),
            RepeatBehavior = RepeatBehavior.Forever,
        };

        Storyboard.SetTarget(Rotation3DAnimation, geoModel.Transform);
        Storyboard.SetTargetProperty(Rotation3DAnimation, new PropertyPath("Rotation"));

        rotateStoryboard.Children.Add(Rotation3DAnimation);
        rotateStoryboard.Begin();
    }

这不起作用...没有任何改变？

谢谢！

Answer 1

我不确定我是否正确理解了您要完成的工作，所以如果我误解了，请告诉我： 在您展示的代码中，您正在加载几个 GeometryModel3D，那么您是想让它们全部旋转还是只旋转一个？

让它旋转的一种方法是通过 GeometryModel3D 的 Transform 属性。

您必须设置 DispatcherTimer 并更新每个 Tick 的旋转角度：

我根据您提供的内容制作了一个示例，我在其中旋转了一个 3D 模型：

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        this.Load3dModel();
        this.timer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(10) };
        this.timer.Tick += Timer_Tick;
        this.timer.Start();
    }

    /// <summary>
    /// Change the rotation
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void Timer_Tick(object sender, EventArgs e)
    {
        if (this.angle >= 360)
        {
            this.angle = 0;
        }
        else
        {
            //Nothing to do
        }
        this.angle = this.angle + 0.25;
        //You can adapt the code if you have many children 
        GeometryModel3D geometryModel3D = (GeometryModel3D)((Model3DGroup)visualModel.Content).Children.First();
        if (geometryModel3D.Transform is RotateTransform3D rotateTransform3 && rotateTransform3.Rotation is AxisAngleRotation3D rotation)
        {
            rotation.Angle = this.angle;
        }
        else
        {
            ///Initialize the Transform (I didn't do it in my example but you could do this initialization in <see Load3dModel/>)
            geometryModel3D.Transform = new RotateTransform3D()
            {
                Rotation = new AxisAngleRotation3D()
                {
                    Axis = new Vector3D(0, 1, 0),
                    Angle = this.angle,
                }
            };
        }
    }

    private DispatcherTimer timer;

    public void Load3dModel()
    {
        StLReader stlReader = new StLReader();
        /*
        Model3DGroup MyModel = stlReader.Read(OrLoadFromPath));
        */
        Model3DGroup myModel = new Model3DGroup();
        // Create a mesh builder and add a box to it
        var meshBuilder = new MeshBuilder(false, false);
        meshBuilder.AddBox(new Point3D(0, 0, 1), 1, 2, 0.5);
        meshBuilder.AddBox(new Rect3D(0, 0, 1.2, 0.5, 1, 0.4));

        // Create a mesh from the builder (and freeze it)
        var mesh = meshBuilder.ToMesh(true);

        // Add 3 models to the group (using the same mesh, that's why we had to freeze it)
        myModel.Children.Add(new GeometryModel3D { Geometry = mesh});
        myModel.Children.Add(new GeometryModel3D { Geometry = mesh, Transform = new TranslateTransform3D(-2, 0, 0)});
        myModel.Children.Add(new GeometryModel3D { Geometry = mesh, Transform = new TranslateTransform3D(2, 0, 0)});

        System.Windows.Media.Media3D.Material mat = MaterialHelper.CreateMaterial(new SolidColorBrush(Color.FromRgb(255, 255, 255)));

        foreach (System.Windows.Media.Media3D.GeometryModel3D geometryModel in myModel.Children)
        {
            geometryModel.Material = mat;
            geometryModel.BackMaterial = mat;
        }

        visualModel.Content = myModel;
    }

    private double angle = 0;
}

使用这些参数，我的旋转非常顺利，但您必须在您的应用程序上测试/调整它。