具有正交相机剪裁的 Viewport3D
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【中文标题】具有正交相机剪裁的 Viewport3D【英文标题】：Viewport3D with orthographic camera clipping 【发布时间】：2014-12-09 04:03:22 【问题描述】：将 ViewPort3D 与正交相机一起使用时，3D 模型正在裁剪，如下面的第二个链接所示。就好像视图是基于透视相机并且不显示其背后的东西，即使它使用的是正交相机。
View of the entire 3D model
Perspective view & Orthographic view
上面使用代码生成图片
Used code to generate pictures above (toggling Orthographic to True/False)
<Window x:Class="HelixToolkitTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:helix="http://helix-toolkit.org/wpf"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<GeometryModel3D x:Key="GeometryModel">
<GeometryModel3D.Geometry>
<MeshGeometry3D
TriangleIndices="0,1,2 3,4,5 "
Normals="0,0,1 0,0,1 0,0,1 0,0,1 0,0,1 0,0,1 "
TextureCoordinates="0,0 1,0 1,1 1,1 0,1 0,0 "
Positions="-0.5,-0.5,0.5 0.5,-0.5,0.5 0.5,0.5,0.5 0.5,0.5,0.5 -0.5,0.5,0.5 -0.5,-0.5,0.5 " />
</GeometryModel3D.Geometry>
<GeometryModel3D.Material>
<MaterialGroup>
<DiffuseMaterial>
<DiffuseMaterial.Brush>
<LinearGradientBrush StartPoint="0,0.5" EndPoint="1,0.5">
<LinearGradientBrush.GradientStops>
<GradientStop Color="Yellow" Offset="0" />
<GradientStop Color="Red" Offset="0.25" />
<GradientStop Color="Blue" Offset="0.75" />
<GradientStop Color="LimeGreen" Offset="1" />
</LinearGradientBrush.GradientStops>
</LinearGradientBrush>
</DiffuseMaterial.Brush>
</DiffuseMaterial>
</MaterialGroup>
</GeometryModel3D.Material>
<GeometryModel3D.Transform>
<ScaleTransform3D ScaleX="50" ScaleY="1" ScaleZ="1"/>
</GeometryModel3D.Transform>
</GeometryModel3D>
<DirectionalLight x:Key="DirectionalLight" Color="#FFFFFF" Direction="-0.612372,-0.5,-0.612372" />
</Window.Resources>
<UniformGrid Columns="3">
<GroupBox Header="Perspective camera">
<Viewport3D>
<Viewport3D.Camera>
<PerspectiveCamera FarPlaneDistance="Infinity" NearPlaneDistance="0.1" LookDirection="12.064,-1.167,-0.831" UpDirection="-0.73,0.071,0.679"
Position="-12.064,1.167,0.831"/>
</Viewport3D.Camera>
<ModelVisual3D Content="StaticResource DirectionalLight"/>
<ModelVisual3D Content="StaticResource GeometryModel"/>
</Viewport3D>
</GroupBox>
<GroupBox Header="Orthographic camera">
<Viewport3D>
<Viewport3D.Camera>
<OrthographicCamera FarPlaneDistance="Infinity" NearPlaneDistance="0.1" LookDirection="12.064,-1.167,-0.831" UpDirection="-0.73,0.071,0.679"
Position="-12.064,1.167,0.831" Width="9.313"/>
</Viewport3D.Camera>
<ModelVisual3D Content="StaticResource DirectionalLight"/>
<ModelVisual3D Content="StaticResource GeometryModel"/>
</Viewport3D>
</GroupBox>
知道如何解决这个问题吗？
谢谢，
编辑：我实际上找到了解决方案，您只需将正交相机的NearPlaneDistance设置为-Infinity，请参见下面的代码：
<Window x:Class="HelixToolkitTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:helix="http://helix-toolkit.org/wpf"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<GeometryModel3D x:Key="GeometryModel">
<GeometryModel3D.Geometry>
<MeshGeometry3D
TriangleIndices="0,1,2 3,4,5 "
Normals="0,0,1 0,0,1 0,0,1 0,0,1 0,0,1 0,0,1 "
TextureCoordinates="0,0 1,0 1,1 1,1 0,1 0,0 "
Positions="-0.5,-0.5,0.5 0.5,-0.5,0.5 0.5,0.5,0.5 0.5,0.5,0.5 -0.5,0.5,0.5 -0.5,-0.5,0.5 " />
</GeometryModel3D.Geometry>
<GeometryModel3D.Material>
<MaterialGroup>
<DiffuseMaterial>
<DiffuseMaterial.Brush>
<LinearGradientBrush StartPoint="0,0.5" EndPoint="1,0.5">
<LinearGradientBrush.GradientStops>
<GradientStop Color="Yellow" Offset="0" />
<GradientStop Color="Red" Offset="0.25" />
<GradientStop Color="Blue" Offset="0.75" />
<GradientStop Color="LimeGreen" Offset="1" />
</LinearGradientBrush.GradientStops>
</LinearGradientBrush>
</DiffuseMaterial.Brush>
</DiffuseMaterial>
</MaterialGroup>
</GeometryModel3D.Material>
<GeometryModel3D.Transform>
<ScaleTransform3D ScaleX="50" ScaleY="1" ScaleZ="1"/>
</GeometryModel3D.Transform>
</GeometryModel3D>
<DirectionalLight x:Key="DirectionalLight" Color="#FFFFFF" Direction="-0.612372,-0.5,-0.612372" />
</Window.Resources>
<UniformGrid Columns="3">
<GroupBox Header="Perspective camera">
<Viewport3D>
<Viewport3D.Camera>
<PerspectiveCamera FarPlaneDistance="Infinity" NearPlaneDistance="0.1" LookDirection="12.064,-1.167,-0.831" UpDirection="-0.73,0.071,0.679"
Position="-12.064,1.167,0.831"/>
</Viewport3D.Camera>
<ModelVisual3D Content="StaticResource DirectionalLight"/>
<ModelVisual3D Content="StaticResource GeometryModel"/>
</Viewport3D>
</GroupBox>
<GroupBox Header="Orthographic camera">
<Viewport3D>
<Viewport3D.Camera>
<OrthographicCamera FarPlaneDistance="Infinity" NearPlaneDistance="-Infinity" LookDirection="12.064,-1.167,-0.831" UpDirection="-0.73,0.071,0.679"
Position="-12.064,1.167,0.831" Width="9.313"/>
</Viewport3D.Camera>
<ModelVisual3D Content="StaticResource DirectionalLight"/>
<ModelVisual3D Content="StaticResource GeometryModel"/>
</Viewport3D>
</GroupBox>
【问题讨论】：
你期待什么？我看不出代码和行为有什么问题。您使用了一个 GeometryModel3D，并且您看到了它，形成了两种相机类型。 我期待看到整个模型（带有黄色部分），如下图所示：Perspective view & Orthographic view。但现在没关系，我找到了解决方案（见上面编辑过的问题）。 然后把你的相机移远一点。 而不是设置负的 NearPlaneDistance，微软不建议这样做，而是像 AgentFire 建议的那样将相机移得更远。另外，尝试增加 LookDirection 向量的大小。通常这无关紧要，除了 Helix ZoomToExtents 方法使用 LookDirection 向量作为相对偏移来重新定位相机。 【参考方案1】：我和你有同样的问题。测试了几个解决方案终于找到了解决方案。
您必须增加或定义PerspectiveCamera的FarPlaneDistance属性。
祝你好运
【讨论】：
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