WPF 中的动态运行时 3D 点

Question

我正在尝试使用 WPF 创建 3D 点的动态视图，我能够绘制第一组点，但随后它崩溃了，因为 Mesh3DGeometry 被冻结了.. 是否可以解冻 Mesh3DGeomerty 并清除网格以便可以绘制下一组？

    var rand = new Random();
while (true)
{
    points.Clear();
    for (int i = 0; i < 100; i++)
    {
        points.Add(new Point3D(rand.NextDouble(), rand.NextDouble(), rand.NextDouble()));
    }
    for (int i = 0; i < points.Count; i++)
    {
        AddCubeToMesh(pointCloudMesh, points[i], 0.01);
    }
    pointCloudMesh.Freeze();
}

还有XAML在这里

<Grid Grid.Row="1" Grid.Column="1"  Margin="0 20 0 -20" Background="LightGray" Name="MyCanvas" >
                <Viewport3D>
                    <Viewport3D.Camera>
                        <PerspectiveCamera x:Name="camMain" Position="0 0 5" LookDirection="0 0 -5"/>
                    </Viewport3D.Camera>

                    <ModelVisual3D>
                        <ModelVisual3D.Content>
                            <Model3DGroup>
                                <Model3DGroup.Children>
                                    <AmbientLight Color="#AAAAAA" />
                                </Model3DGroup.Children>
                            </Model3DGroup>
                        </ModelVisual3D.Content>
                    </ModelVisual3D>

                    <ModelVisual3D>
                        <ModelVisual3D.Content>
                            <GeometryModel3D>
                                <GeometryModel3D.Geometry>
                                    <MeshGeometry3D x:Name="pointCloudMesh" />
                                </GeometryModel3D.Geometry>
                                <GeometryModel3D.Material>
                                    <DiffuseMaterial Brush="Red"/>
                                </GeometryModel3D.Material>
                            </GeometryModel3D>
                        </ModelVisual3D.Content>
                    </ModelVisual3D>
                </Viewport3D>
            </Grid>

AddCubeToMesh 代码

private void AddCubeToMesh(MeshGeometry3D mesh, Point3D center, double size)
    {
        if (mesh != null)
        {
            int offset = mesh.Positions.Count;

            mesh.Positions.Add(new Point3D(center.X - size, center.Y + size, center.Z - size));
            mesh.Positions.Add(new Point3D(center.X + size, center.Y + size, center.Z - size));
            mesh.Positions.Add(new Point3D(center.X + size, center.Y + size, center.Z + size));
            mesh.Positions.Add(new Point3D(center.X - size, center.Y + size, center.Z + size));
            mesh.Positions.Add(new Point3D(center.X - size, center.Y - size, center.Z - size));
            mesh.Positions.Add(new Point3D(center.X + size, center.Y - size, center.Z - size));
            mesh.Positions.Add(new Point3D(center.X + size, center.Y - size, center.Z + size));
            mesh.Positions.Add(new Point3D(center.X - size, center.Y - size, center.Z + size));

            mesh.TriangleIndices.Add(offset + 3);
            mesh.TriangleIndices.Add(offset + 2);
            mesh.TriangleIndices.Add(offset + 6);

            mesh.TriangleIndices.Add(offset + 3);
            mesh.TriangleIndices.Add(offset + 6);
            mesh.TriangleIndices.Add(offset + 7);

            mesh.TriangleIndices.Add(offset + 2);
            mesh.TriangleIndices.Add(offset + 1);
            mesh.TriangleIndices.Add(offset + 5);

            mesh.TriangleIndices.Add(offset + 2);
            mesh.TriangleIndices.Add(offset + 5);
            mesh.TriangleIndices.Add(offset + 6);

            mesh.TriangleIndices.Add(offset + 1);
            mesh.TriangleIndices.Add(offset + 0);
            mesh.TriangleIndices.Add(offset + 4);

            mesh.TriangleIndices.Add(offset + 1);
            mesh.TriangleIndices.Add(offset + 4);
            mesh.TriangleIndices.Add(offset + 5);

            mesh.TriangleIndices.Add(offset + 0);
            mesh.TriangleIndices.Add(offset + 3);
            mesh.TriangleIndices.Add(offset + 7);

            mesh.TriangleIndices.Add(offset + 0);
            mesh.TriangleIndices.Add(offset + 7);
            mesh.TriangleIndices.Add(offset + 4);

            mesh.TriangleIndices.Add(offset + 7);
            mesh.TriangleIndices.Add(offset + 6);
            mesh.TriangleIndices.Add(offset + 5);

            mesh.TriangleIndices.Add(offset + 7);
            mesh.TriangleIndices.Add(offset + 5);
            mesh.TriangleIndices.Add(offset + 4);

            mesh.TriangleIndices.Add(offset + 2);
            mesh.TriangleIndices.Add(offset + 3);
            mesh.TriangleIndices.Add(offset + 0);

            mesh.TriangleIndices.Add(offset + 2);
            mesh.TriangleIndices.Add(offset + 0);
            mesh.TriangleIndices.Add(offset + 1);
        }
    }

我有点用的解决方案是将所有这些添加到一个单独的 UserControl 中，并在每次新数据到达时调用它

Answer 1

首先：在不给 UI 线程时间的情况下生成 UI 部分的无限循环将不起作用。在单独的线程上生成数据并将数据传递给 UI 线程以创建模型并显示它。

然后，无法解冻可冻结对象：

"Unfreezing" a Freezable Once frozen, a Freezable can never be modified or unfrozen; however, you can create an unfrozen clone using the Clone or CloneCurrentValue method.

Source

因此，如果您认为确实需要 Freeze/Unfreeze，您可以通过克隆来实现。我认为这里不需要。

Answer 2

我想出的解决方案是将点云视图与另一个用户控件分开，每次我想显示一组新数据时，我都会销毁旧的用户控件并重建它..这是一种激进的方法，但有效很好

XAML 用于新的用户控件

<UserControl x:Class="LPDTool.View3D"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         xmlns:local="clr-namespace:LPDTool"
         mc:Ignorable="d" 
         d:DesignHeight="500" d:DesignWidth="500"
         KeyDown="Window_KeyDown">
<GroupBox x:Name="GBox" Margin="0 20 0 -20" Foreground="#AAAAAA" FontSize="18" FontWeight="Medium" Background="#DDDBDA" BorderBrush="#7B7704" BorderThickness="2" FontFamily="Abadi MT">
    <Viewport3D>
        <Viewport3D.Camera>
            <PerspectiveCamera x:Name="camMain"/>
        </Viewport3D.Camera>
        <ModelVisual3D>
            <ModelVisual3D.Content>
                <Model3DGroup>
                    <Model3DGroup.Children>
                        <AmbientLight Color="#AAAAAA" />
                    </Model3DGroup.Children>
                </Model3DGroup>
            </ModelVisual3D.Content>
        </ModelVisual3D>
        <ModelVisual3D>
            <ModelVisual3D.Content>
                <GeometryModel3D>
                    <GeometryModel3D.Geometry>
                        <MeshGeometry3D x:Name="pointCloudMesh" />
                    </GeometryModel3D.Geometry>
                    <GeometryModel3D.Material>
                        <DiffuseMaterial Brush="Red"/>
                    </GeometryModel3D.Material>
                </GeometryModel3D>
            </ModelVisual3D.Content>
        </ModelVisual3D>
    </Viewport3D>
</GroupBox>

初始化构造函数

public View3D()
    {

        InitializeComponent();
        PositionCamera();

        for (int i = 0; i < LPDTest.points.Count; i++)
        {
            AddCubeToMesh(pointCloudMesh, points[i], 0.02);
        }
    }

XAML为包含部分

<Grid x:Name="My3dview">

</Grid>

这里是生成代码部分（带有dumpy数据）

var rand = new Random();
while (true)
{
    My3dview.Children.Clear();
    points.Clear();
    for (int i = 0; i < 100; i++)
    {
        points.Add(new Point3D(rand.NextDouble(), rand.NextDouble(), rand.NextDouble()));
    }
    My3dview.Children.Add(new View3D());
}

WPF 中的动态运行时 3D 点

Dynamic Runtime 3D Points in WPF

wpf

3d

point-clouds