How to: Apply Multiple Transformations to a 3-D Model

This sample shows how to use a RotateTransform3D and a ScaleTransform3D to rotate and change the scale of a 3-D model. The code below shows how to apply these transforms to the Transform property of a GeometryModel3D in XAML.

<!-- Apply multiple transformations to the object. In this sample, a rotation and scale transform 
is applied. -->
<GeometryModel3D.Transform>
  <Transform3DGroup>
    <Transform3DGroup.Children>
      <RotateTransform3D>
        <RotateTransform3D.Rotation>

        <!-- This transformation rotates the object. -->
        <AxisAngleRotation3D Axis="0,3,0" Angle="40" />
        </RotateTransform3D.Rotation>
      </RotateTransform3D>
      
      <!-- This Scale Transform stretches the object horizontally by 200 percent and shrinks it 
         vertically by 50 percent. -->
      <ScaleTransform3D ScaleX="2" ScaleY="0.5" ScaleZ="1" CenterX="0" CenterY="0" CenterZ="0" />
    </Transform3DGroup.Children>
 </Transform3DGroup>
</GeometryModel3D.Transform>

In code:

// Apply multiple transformations to the object. In this sample, a rotation and scale 
// transform is applied.

// Create and apply a transformation that rotates the object.
RotateTransform3D myRotateTransform3D = new RotateTransform3D();
AxisAngleRotation3D myAxisAngleRotation3d = new AxisAngleRotation3D();
myAxisAngleRotation3d.Axis = new Vector3D(0,3,0);
myAxisAngleRotation3d.Angle = 40;
myRotateTransform3D.Rotation = myAxisAngleRotation3d;

// Add the rotation transform to a Transform3DGroup
Transform3DGroup myTransform3DGroup = new Transform3DGroup();
myTransform3DGroup.Children.Add(myRotateTransform3D);

// Create and apply a scale transformation that stretches the object horizontally by  
// 200 percent and shrinks it vertically by 50 percent.
ScaleTransform3D myScaleTransform3D = new ScaleTransform3D();
myScaleTransform3D.ScaleX = 2;
myScaleTransform3D.ScaleY = 0.5;
myScaleTransform3D.ScaleZ = 1;

// Add the scale transform to the Transform3DGroup.
myTransform3DGroup.Children.Add(myScaleTransform3D);

// Set the Transform property of the GeometryModel to the Transform3DGroup which includes 
// both transformations. The 3D object now has two Transformations applied to it.
myGeometryModel.Transform = myTransform3DGroup;

Example

The following code shows the entire sample in XAML.

<Page xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml" >
  <DockPanel>
    <Viewbox>
      <Canvas Width="321" Height="201">

        <!-- The Viewport3D provides a rendering surface for 3-D visual content. -->
        <Viewport3D ClipToBounds="True" Width="150" Height="150" Canvas.Left="0" Canvas.Top="10">

          <!-- Defines the camera used to view the 3D object. -->
          <Viewport3D.Camera>
            <PerspectiveCamera Position="0,0,2" LookDirection="0,0,-1" FieldOfView="60" />
          </Viewport3D.Camera>

          <!-- The ModelVisual3D children contain the 3D models -->
          <Viewport3D.Children>

            <!-- This ModelVisual3D defines the light cast in the scene. Without light, the 3D 
                 object cannot be seen. Also, the direction of the lights affect shadowing. If desired,
                 you can create multiple lights with different colors that shine from different directions. -->
            <ModelVisual3D>
              <ModelVisual3D.Content>
                <DirectionalLight Color="#FFFFFF" Direction="-0.612372,-0.5,-0.612372" />
              </ModelVisual3D.Content>
            </ModelVisual3D>
            <ModelVisual3D>
              <ModelVisual3D.Content>
                <GeometryModel3D>

                  <!-- The geometry specifes the shape of the 3D plane. In this sample, a flat sheet is created. -->
                  <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>

                  <!-- The material specifies the material applied to the 3D object. In this sample a linear gradient 
                       covers the surface of the 3D object.-->
                  <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>
                  <!-- Apply multiple transformations to the object. In this sample, a rotation and scale transform 
                  is applied. -->
                  <GeometryModel3D.Transform>
                    <Transform3DGroup>
                      <Transform3DGroup.Children>
                        <RotateTransform3D>
                          <RotateTransform3D.Rotation>

                          <!-- This transformation rotates the object. -->
                          <AxisAngleRotation3D Axis="0,3,0" Angle="40" />
                          </RotateTransform3D.Rotation>
                        </RotateTransform3D>
                        
                        <!-- This Scale Transform stretches the object horizontally by 200 percent and shrinks it 
                           vertically by 50 percent. -->
                        <ScaleTransform3D ScaleX="2" ScaleY="0.5" ScaleZ="1" CenterX="0" CenterY="0" CenterZ="0" />
                      </Transform3DGroup.Children>
                   </Transform3DGroup>
                  </GeometryModel3D.Transform>
                </GeometryModel3D>
              </ModelVisual3D.Content>
            </ModelVisual3D>
          </Viewport3D.Children>

        </Viewport3D>
      </Canvas>
    </Viewbox>
  </DockPanel>
</Page>

Below is the entire sample in code.

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Media3D;

namespace SDKSample
{
    public partial class MultipleTransformationsExample : Page
    {
        public MultipleTransformationsExample()
        {

            // Declare scene objects.
            Viewport3D myViewport3D = new Viewport3D();
            Model3DGroup myModel3DGroup = new Model3DGroup();
            GeometryModel3D myGeometryModel = new GeometryModel3D();
            ModelVisual3D myModelVisual3D = new ModelVisual3D();
            // Defines the camera used to view the 3D object. In order to view the 3D object,
            // the camera must be positioned and pointed such that the object is within view 
            // of the camera.
            PerspectiveCamera myPCamera = new PerspectiveCamera();

            // Specify where in the 3D scene the camera is.
            myPCamera.Position = new Point3D(0, 0, 2);

            // Specify the direction that the camera is pointing.
            myPCamera.LookDirection = new Vector3D(0, 0, -1);

            // Define camera's horizontal field of view in degrees.
            myPCamera.FieldOfView = 60;

            // Asign the camera to the viewport
            myViewport3D.Camera = myPCamera;
            // Define the lights cast in the scene. Without light, the 3D object cannot 
            // be seen. Also, the direction of the lights affect shadowing. Note: to 
            // illuminate an object from additional directions, create additional lights.
            DirectionalLight myDirectionalLight = new DirectionalLight();
            myDirectionalLight.Color = Colors.White;
            myDirectionalLight.Direction = new Vector3D(-0.61, -0.5, -0.61);

            myModel3DGroup.Children.Add(myDirectionalLight);

            // The geometry specifes the shape of the 3D plane. In this sample, a flat sheet 
            // is created.
            MeshGeometry3D myMeshGeometry3D = new MeshGeometry3D();

            // Create a collection of normal vectors for the MeshGeometry3D.
            Vector3DCollection myNormalCollection = new Vector3DCollection();
            myNormalCollection.Add(new Vector3D(0,0,1));
            myNormalCollection.Add(new Vector3D(0,0,1));
            myNormalCollection.Add(new Vector3D(0,0,1));
            myNormalCollection.Add(new Vector3D(0,0,1));
            myNormalCollection.Add(new Vector3D(0,0,1));
            myNormalCollection.Add(new Vector3D(0,0,1));
            myMeshGeometry3D.Normals = myNormalCollection;

            // Create a collection of vertex positions for the MeshGeometry3D. 
            Point3DCollection myPositionCollection = new Point3DCollection();
            myPositionCollection.Add(new Point3D(-0.5, -0.5, 0.5));
            myPositionCollection.Add(new Point3D(0.5, -0.5, 0.5));
            myPositionCollection.Add(new Point3D(0.5, 0.5, 0.5));
            myPositionCollection.Add(new Point3D(0.5, 0.5, 0.5));
            myPositionCollection.Add(new Point3D(-0.5, 0.5, 0.5));
            myPositionCollection.Add(new Point3D(-0.5, -0.5, 0.5));
            myMeshGeometry3D.Positions = myPositionCollection;

            // Create a collection of texture coordinates for the MeshGeometry3D.
            PointCollection myTextureCoordinatesCollection = new PointCollection();
            myTextureCoordinatesCollection.Add(new Point(0, 0));
            myTextureCoordinatesCollection.Add(new Point(1, 0));
            myTextureCoordinatesCollection.Add(new Point(1, 1));
            myTextureCoordinatesCollection.Add(new Point(1, 1));
            myTextureCoordinatesCollection.Add(new Point(0, 1));
            myTextureCoordinatesCollection.Add(new Point(0, 0));
            myMeshGeometry3D.TextureCoordinates = myTextureCoordinatesCollection;

            // Create a collection of triangle indices for the MeshGeometry3D.
            Int32Collection myTriangleIndicesCollection = new Int32Collection();
            myTriangleIndicesCollection.Add(0);
            myTriangleIndicesCollection.Add(1);
            myTriangleIndicesCollection.Add(2);
            myTriangleIndicesCollection.Add(3);
            myTriangleIndicesCollection.Add(4);
            myTriangleIndicesCollection.Add(5);
            myMeshGeometry3D.TriangleIndices = myTriangleIndicesCollection;

            // Apply the mesh to the geometry model.
            myGeometryModel.Geometry = myMeshGeometry3D;

            // The material specifies the material applied to the 3D object. In this sample a  
            // linear gradient covers the surface of the 3D object.

            // Create a horizontal linear gradient with four stops.   
            LinearGradientBrush myHorizontalGradient = new LinearGradientBrush();
            myHorizontalGradient.StartPoint = new Point(0, 0.5);
            myHorizontalGradient.EndPoint = new Point(1, 0.5);
            myHorizontalGradient.GradientStops.Add(new GradientStop(Colors.Yellow, 0.0));
            myHorizontalGradient.GradientStops.Add(new GradientStop(Colors.Red, 0.25));
            myHorizontalGradient.GradientStops.Add(new GradientStop(Colors.Blue, 0.75));
            myHorizontalGradient.GradientStops.Add(new GradientStop(Colors.LimeGreen, 1.0));

            // Define material and apply to the mesh geometries.
            DiffuseMaterial myMaterial = new DiffuseMaterial(myHorizontalGradient);
            myGeometryModel.Material = myMaterial;
            // Apply multiple transformations to the object. In this sample, a rotation and scale 
            // transform is applied.

            // Create and apply a transformation that rotates the object.
            RotateTransform3D myRotateTransform3D = new RotateTransform3D();
            AxisAngleRotation3D myAxisAngleRotation3d = new AxisAngleRotation3D();
            myAxisAngleRotation3d.Axis = new Vector3D(0,3,0);
            myAxisAngleRotation3d.Angle = 40;
            myRotateTransform3D.Rotation = myAxisAngleRotation3d;

            // Add the rotation transform to a Transform3DGroup
            Transform3DGroup myTransform3DGroup = new Transform3DGroup();
            myTransform3DGroup.Children.Add(myRotateTransform3D);

            // Create and apply a scale transformation that stretches the object horizontally by  
            // 200 percent and shrinks it vertically by 50 percent.
            ScaleTransform3D myScaleTransform3D = new ScaleTransform3D();
            myScaleTransform3D.ScaleX = 2;
            myScaleTransform3D.ScaleY = 0.5;
            myScaleTransform3D.ScaleZ = 1;

            // Add the scale transform to the Transform3DGroup.
            myTransform3DGroup.Children.Add(myScaleTransform3D);

            // Set the Transform property of the GeometryModel to the Transform3DGroup which includes 
            // both transformations. The 3D object now has two Transformations applied to it.
            myGeometryModel.Transform = myTransform3DGroup;
            // Add the geometry model to the model group.
            myModel3DGroup.Children.Add(myGeometryModel);

            // Add the group of models to the ModelVisual3d.
            myModelVisual3D.Content = myModel3DGroup;

            myViewport3D.Children.Add(myModelVisual3D);

            // Apply the viewport to the page so it will be rendered.
            this.Content = myViewport3D;
        }
    }
}

See Also

Tasks

How to: Transform the Scale of a 3-D Model