WPF将一个平面映射到一个球体上，比如一个地球仪

Question

我正在尝试放置一个图像画笔。WPF中的一个球体。我用来生成球体的代码是:

生成球体

如果我使用颜色作为画笔，效果非常好。但如果我试着用地球的平面图像。这篇文章的图片

我就是不能在球体上正确地绘制图像。能想到的我都试过了。我认为这与"TextureCoordinates"有关，但我能找到的唯一合适的例子是处理三角形。可我还是不知道该做什么。

我要编写的应用程序有几百张"平面"的全球地图。上面有各种信息图形。

这是我为页面准备的XAML代码，到目前为止还没有代码。

谢谢

<Page x:Class="GlobeViewer"
      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:Help3D="clr-namespace:Framework.Help3D"
      mc:Ignorable="d" 
      d:DesignHeight="1080" d:DesignWidth="1920"
    Title="GlobeViewer.xaml">
    <Grid xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Background="Black">
        <Grid.Resources>
            <MeshGeometry3D x:Key="Globe" Positions="{Binding Path=Globe.Points, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"
                TriangleIndices="{Binding Path=Globe.TriangleIndices, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Page}}"
                            TextureCoordinates="0,0 512,0 512,256 0,256 "/>
            <MaterialGroup x:Key="GlobeTexture">
                <DiffuseMaterial >
                    <DiffuseMaterial.Brush>
                        <ImageBrush  ImageSource="D:_devGlobeViewerAssetsPagesglobeviewerearth.jpg" 
                                     ViewportUnits="Absolute"  
                                     AlignmentX="Left" 
                                     AlignmentY="Top"
                                     />
                    <!--<SolidColorBrush Color="Red"/>-->
                    </DiffuseMaterial.Brush>
                </DiffuseMaterial>
                <SpecularMaterial Brush="White" SpecularPower="20" />
            </MaterialGroup>
        </Grid.Resources>
        <!--<Image Source="/Assets/Pages/globeviewer/World_3D_Grass.png" />-->
        <Viewport3D>
            <Viewport3D.Camera>
                <PerspectiveCamera x:Name="myCamera" Position="60 40 0" 
                      LookDirection="-50 -33 0" 
                      UpDirection="0,1,0" FieldOfView="90"/>
            </Viewport3D.Camera>
            <ModelVisual3D>
                <ModelVisual3D.Content>
                    <Model3DGroup>
                        <AmbientLight Color="White"/>
                        <DirectionalLight Color="White" 
                                 Direction="0 -30 0" />
                        <GeometryModel3D Geometry="{StaticResource Globe}" Material="{StaticResource GlobeTexture}"/>
                    </Model3DGroup>
                </ModelVisual3D.Content>
            </ModelVisual3D>
        </Viewport3D>
    </Grid>
</Page>

Answer 1

  System.Drawing.Image image1 = new Bitmap(Server.MapPath(
    ""));
Bitmap imgBitmap = new Bitmap(image1);
 for (int i = 0; i < imgBitmap.Width; i++)
         {
         for (int j = 0; j < imgBitmap.Height; j++)
              {
              // map the angles from image coordinates
              double theta = Algebra.MapCoordinate(0.0, imgBitmap.Width - 1,
                  theta1, theta0, i);
              double phi = Algebra.MapCoordinate( 0.0, imgBitmap.Height - 1,phi0,
                  phi1, j);
              // find the cartesian coordinates
              double x = radius * Math.Sin(phi) * Math.Cos(theta);
              double y = radius * Math.Sin(phi) * Math.Sin(theta);
              double z = radius * Math.Cos(phi);
              // apply rotation around X and Y axis to reposition the sphere
              RotX(1.5, ref y, ref z);
              RotY(-2.5, ref x, ref z);
              // plot only positive points
              if (z > 0)
                   {
                   Color color = imgBitmap.GetPixel(i, j);
                   Brush brs = new SolidBrush(color);
                   int ix = (int)x + 100;
                   int iy = (int)y + 100;
                   graphics.FillRectangle(brs, ix, iy, 1, 1);
                   brs.Dispose();
                  }
              }
         }