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奇怪的问题，但我发现 RenderTargetBitmap 函数正在渲染 ViewPort3D 左侧的边距。当我保存位图（在这种情况下为 PNG）时，最终图像的左侧有一个间隙，而右侧被切掉了相同的数量。ViewPort3D 的尺寸为 550 像素高 x 1024 像素宽。我在 RenderTargetBitmap 方法中使用相同的尺寸。我很困惑为什么它超出了定义的界限。

    <Grid>
    <Button Content="Save Snapshot" HorizontalAlignment="Left" Name="btnSaveSnapshot"  VerticalAlignment="Top" Width="100" Margin="8,8,0,0"/>
    <Viewport3D Name="vp3dTiles" Height="550" Width="1024" UseLayoutRounding="True"  HorizontalAlignment="Center" VerticalAlignment="Bottom" >
        <Viewport3D.Camera>
            <PerspectiveCamera Position="384,1750,174" LookDirection="0,-.65,-0.25"  UpDirection="0,0,1"  FieldOfView="65"/>
        </Viewport3D.Camera>
        <ModelVisual3D>
            <ModelVisual3D.Content>
                <Model3DGroup>
                    <AmbientLight Color="white" />
                    <GeometryModel3D>
                        <GeometryModel3D.Geometry>
                            <MeshGeometry3D Positions="0,0,0 768,0,0 768,1408,0 0,1408,0 " TriangleIndices="0 1 3 1 2 3" TextureCoordinates="0,0 760,0 760,1408 0,1408 "/>                             
                        </GeometryModel3D.Geometry>
                        <GeometryModel3D.Material>                               
                            <DiffuseMaterial>
                                <DiffuseMaterial.Brush>
                                    <ImageBrush ViewportUnits="Absolute" TileMode="Tile" ImageSource="FlorVintage_FINAL.png" Viewport="0,0,768,1408" ViewboxUnits="Absolute" Stretch="None" AlignmentY="Top" RenderOptions.BitmapScalingMode="NearestNeighbor" AlignmentX="Left" />
                                </DiffuseMaterial.Brush> 
                            </DiffuseMaterial>
                        </GeometryModel3D.Material>

                    </GeometryModel3D>
                </Model3DGroup>
            </ModelVisual3D.Content>
        </ModelVisual3D>
    </Viewport3D>

</Grid>

后面的代码（在 VB 中 - 抱歉）：

    Private Sub btnSaveSnapshot_Click(sender As Object, e As RoutedEventArgs) Handles btnSaveSnapshot.Click
    Dim bmp As New RenderTargetBitmap(1024, 550, 96, 96, PixelFormats.Pbgra32)
    bmp.Render(Me.vp3dTiles)
    Dim png As New PngBitmapEncoder()
    png.Frames.Add(BitmapFrame.Create(bmp))
    Using stm As Stream = File.Create(My.Settings.FileSavePath & "\" & "TestSnapshot.png")
        png.Save(stm)
    End Using
End Sub

我认为它所在的容器（网格）可能是问题所在。

4

2 回答 2

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我有一个答案 - 定义网格行和列并将列宽设置为与 ViewPort3D 相同（只有 1 列）。我还必须在窗口中左对齐网格（如图）。不幸的是，视口向左对齐——即使它被设置为居中——参见代码——这没有意义，但我可以处理丑陋的屏幕。

    <Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="40" ></RowDefinition>
        <RowDefinition Height="*"></RowDefinition>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="1024" MaxWidth="1024" MinWidth="1024"></ColumnDefinition>           
    </Grid.ColumnDefinitions>
    <Button Content="Save Snapshot" Grid.Row="0" HorizontalAlignment="Left" Name="btnSaveSnapshot"  VerticalAlignment="Top" Width="100" Margin="8,8,0,0"/>
    <Viewport3D Name="vp3dTiles"  Grid.Row="1" Height="550" Width="1024" UseLayoutRounding="True"  HorizontalAlignment="Center" VerticalAlignment="Bottom" >
        <Viewport3D.Camera>
            <PerspectiveCamera Position="384,1750,174" LookDirection="0,-.65,-0.25"  UpDirection="0,0,1"  FieldOfView="65"/>
        </Viewport3D.Camera>
        <ModelVisual3D>
            <ModelVisual3D.Content>
                <Model3DGroup>
                    <AmbientLight Color="white" />
                    <GeometryModel3D>
                        <GeometryModel3D.Geometry>
                            <MeshGeometry3D Positions="0,0,0 768,0,0 768,1408,0 0,1408,0 " TriangleIndices="0 1 3 1 2 3" TextureCoordinates="0,0 760,0 760,1408 0,1408 "/>                             
                        </GeometryModel3D.Geometry>
                        <GeometryModel3D.Material>                               
                            <DiffuseMaterial>
                                <DiffuseMaterial.Brush>
                                    <ImageBrush ViewportUnits="Absolute" TileMode="Tile" ImageSource="FlorVintage_FINAL.png" Viewport="0,0,768,1408" ViewboxUnits="Absolute" Stretch="None" AlignmentY="Top" RenderOptions.BitmapScalingMode="NearestNeighbor" AlignmentX="Left" />
                                </DiffuseMaterial.Brush> 
                            </DiffuseMaterial>
                        </GeometryModel3D.Material>

                    </GeometryModel3D>
                </Model3DGroup>
            </ModelVisual3D.Content>
        </ModelVisual3D>
    </Viewport3D>
    </Grid>
于 2013-11-20T01:52:32.027 回答
0

渲染时，视觉尺寸需要与渲染尺寸相匹配，并且需要更新。我使用以下内容：

Dim imageWidth As Double = 2448
Dim imageHeight As Double = 2050
myviewport.Width = imageWidth / 2
myviewport.Height = imageHeight / 2
myviewport.Measure(New Size(imageWidth / 2, imageHeight / 2))
myviewport.Arrange(New Rect(0, 0, imageWidth / 2, imageHeight / 2))
'Capture Image here
myviewport.Width = Double.NaN 'restore previous value here
myviewport.Width = Double.NaN 'restore previous value here
于 2014-03-26T17:31:41.027 回答