SplineQuaternionKeyFrame.KeySpline Property

Gets or sets the two control points that define animation progress for this key frame.

Namespace:  System.Windows.Media.Animation
Assembly:  PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation

public KeySpline KeySpline { get; set; }
<object>
  <object.KeySpline>
    <KeySpline .../>
  </object.KeySpline>
</object>
<object KeySpline="KeySpline" .../>

Property Value

Type: System.Windows.Media.Animation.KeySpline
The two control points that specify the cubic Bezier curve that defines the progress of the key frame.

Identifier field

KeySplineProperty

Metadata properties set to true

None

To understand how a KeySpline works, it is helpful to understand cubic Bezier curves. A cubic Bezier curve is defined by a start point, an end point, and two control points. The two coordinates in the KeySpline define those two control points. When describing key splines, the start point of the Bezier curve is always 0, and the end point is always 1, which is why you define only the two control points. The resulting curve specifies how an animation is interpolated during a time segment; that is, the curve represents the rate of change in the animation's target attribute over the time segment. To better see the relationship between animation progress and a Bezier curve, see Key Spline Animation Sample.

In the following example, QuaternionAnimationUsingKeyFrames is used to make a 3D object rotate. This animation uses the following key frames:

  1. LinearRotation3DKeyFrame is used to create a smooth, linear interpolation between values.

  2. DiscreteRotation3DKeyFrame is used to create sudden "jumps" between values (no interpolation).

  3. SplineRotation3DKeyFrame is used to create a variable transition between values depending on the KeySpline property. In the example below, this part of the animation starts off slow but toward the end of the time segment, speeds up exponentially.


<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://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 x:Name="myPerspectiveCamera" 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 lights cast in the scene. Without light, the
                 3D object cannot be seen. Also, the direction of the lights affect shadowing. -->
            <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 case, 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 plane. In this case it is a linear gradient.-->
                  <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>

                  <!-- The Transform specifies how to transform the 3D object. The rotation
                       is animated using the Storyboard below. -->
                  <GeometryModel3D.Transform>
                    <RotateTransform3D>
                      <RotateTransform3D.Rotation>
                        <QuaternionRotation3D x:Name="myQuaternionRotation3D" />
                      </RotateTransform3D.Rotation>
                    </RotateTransform3D>
                  </GeometryModel3D.Transform>
                </GeometryModel3D>
              </ModelVisual3D.Content>
            </ModelVisual3D>
          </Viewport3D.Children>

          <!-- Trigger the rotation animation when the 3D object loads. -->
          <Viewport3D.Triggers>
            <EventTrigger RoutedEvent="Viewport3D.Loaded">
              <BeginStoryboard>
                <Storyboard>

                  <!-- This animation animates the Rotation property of the RotateTransform
                       causing the 3D shape to rotate and wobble as the rotation angle and 
                       axis are animated. -->
                  <QuaternionAnimationUsingKeyFrames
                   Storyboard.TargetName="myQuaternionRotation3D" 
                   Storyboard.TargetProperty="Quaternion" >
                    <QuaternionAnimationUsingKeyFrames.KeyFrames>

                      <!-- Using a LinearQuaternionKeyFrame, the 3D object gradually rotates from an askew 
                           position to a flat position. -->
                      <LinearQuaternionKeyFrame KeyTime="0:0:1" Value="0,0,1,0"  />

                      <!-- Using a DiscreteQuaternionKeyFrame, the object suddenly rotates to an askew  
                           position. This happens immdeiately after the first 1 and a half seconds of the animation. -->
                      <DiscreteQuaternionKeyFrame KeyTime="0:0:1.5" Value="0.3, 0.3, 1, 0" />

                      <!-- Using a SplineQuaternionKeyFrame, the object rotates back to a flat position. 
                           The animation starts out slowly at first and then speeds up. This KeyFrame ends 
                           after the fourth second. -->
                      <SplineQuaternionKeyFrame KeySpline="0.6,0.0 0.9,0.00" KeyTime="0:0:4" Value="0,0,1,0" />

                    </QuaternionAnimationUsingKeyFrames.KeyFrames>
                  </QuaternionAnimationUsingKeyFrames>

                </Storyboard>
              </BeginStoryboard>
            </EventTrigger>
          </Viewport3D.Triggers>
        </Viewport3D>
      </Canvas>
    </Viewbox>
  </DockPanel>
</Page>


.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Was this page helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

ADD
Show:
© 2015 Microsoft