Code snippets

3D Cloth: Technique For Morphing Meshes

karstenj — Mon, 26 Feb 2007 19:58:18 GMT

It is worth calling out that this uses no XAML and uses a MatrixCamera instead of the more easy-to-grok PerspectiveCamera and OrthographicCamera. And the technique for morphing the mesh is to swap out vertices on the fly using a timer, again not for the feint of heart. But, if you already know 3D paradigms and are wondering how to create stunning effects like this in WPF, this source code will be illuminating for you. [Click to Launch]

The screenshots below give you a sense of what the animation looks like:

Restricting Window movement to the bounds of the Owner window

ifpx895 — Thu, 01 Feb 2007 05:30:10 GMT

This sample provides a way to restrict window movement. In this case, I've restricted it to the Owner bounds. It does not solve all the corner cases, however, it does provide a general mechanism on how such a scenario can be implemented and handles high DPI cases. Furthermore, this sample shows a good way to hook up a listener for win32 window messages.

Proportional Window Sizing

ifpx895 — Thu, 01 Feb 2007 02:15:36 GMT

This sample demonstrates how to proportionally size the window when it is resized by the user by changing either the height of the width using the mouse. The factor we use in this sample is '1'.

The core idea to is to listen to WM_SIZING window message and modifty the RECT to ensure that height and width changes in proportion.

Updated Nine-Grid Sample

Anonymous — Fri, 01 Dec 2006 00:43:04 GMT

Here's the latest version of my NineGrid element, along with a sample program that demonstrates how it works with both vector drawings and bitmap images. The code hasn't changed much since it was posted here last month, but I've renamed the Padding property to BorderThickness, included comments, and added features to the sample application.

To use the NineGrid element, simply add the NineGrid.cs file to your project, make sure you have the proper namespace mapping in your XAML markup, then add a NineGrid element:

Enjoy!

--Eric Stollnitz

Aurora/Smoke Effect

karstenj — Wed, 08 Nov 2006 21:47:43 GMT

Essentially there are 3 layers of the same tiled “clouds” image overlaid on a flat Mesh inside a Viewport3D. Each image has a slight translucency. The Meshes are rotated to be at slight offsets from one another. The layers are then animated through a translation along the x-axis at different velocities. A Linear gradient is then added to act as an Opacity Mask to offer the effect of the smoke fading into darkness. Two light sources are used, one AmbientLight and another DirectionalLight, however you can use whatever combination works best for you.

<Grid xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

<Grid.Resources>

C:\clouds2.png

</ImageSource>

</Grid.Resources>

<Viewport3D.Camera>

</Viewport3D.Camera>

<ModelVisual3D.Content>

<GeometryModel3D.Geometry>

</GeometryModel3D.Geometry>

<GeometryModel3D.Material>

<DiffuseMaterial.Brush>

<VisualBrush.Visual>

<Grid.Triggers>

<DoubleAnimation Storyboard.TargetName="cloud1Transform"

Storyboard.TargetProperty="(TranslateTransform.X)"

From="0" To="1024" RepeatBehavior="Forever" Duration="0:0:12"/>

<DoubleAnimation Storyboard.TargetName="cloud2Transform"

Storyboard.TargetProperty="(TranslateTransform.X)"

From="0" To="1024" RepeatBehavior="Forever" Duration="0:0:16"/>

<DoubleAnimation Storyboard.TargetName="cloud3Transform"

Storyboard.TargetProperty="(TranslateTransform.X)"

From="0" To="1024" RepeatBehavior="Forever" Duration="0:0:20"/> </Storyboard>

</BeginStoryboard>

</EventTrigger>

</Grid.Triggers>

<Grid>

<Grid.Background>

<ImageBrush.Transform>

</TransformGroup>

</ImageBrush.Transform>

</ImageBrush>

</Grid.Background>

</Grid>

<Grid>

<Grid.Background>

<ImageBrush.Transform>

</TransformGroup>

</ImageBrush.Transform>

</ImageBrush>

</Grid.Background>

</Grid>

<Grid>

<Grid.Background>

<ImageBrush.Transform>

</TransformGroup>

</ImageBrush.Transform>

</ImageBrush>

</Grid.Background>

</Grid>

<Grid>

<Grid.Background>

<LinearGradientBrush.GradientStops>

</LinearGradientBrush.GradientStops>

</LinearGradientBrush>

</Grid.Background>

</Grid>

</VisualBrush.Visual>

</VisualBrush>

</DiffuseMaterial.Brush>

</DiffuseMaterial>

</GeometryModel3D.Material>

</GeometryModel3D>

</ModelVisual3D.Content>

</ModelVisual3D>

<ModelVisual3D.Content>

</ModelVisual3D.Content>

</ModelVisual3D>

<ModelVisual3D.Content>

<DirectionalLight.Transform>

</DirectionalLight.Transform>

</DirectionalLight>

</ModelVisual3D.Content>

</ModelVisual3D>

</Viewport3D>

</Grid>

3D Hittesting/Trackball

karstenj — Wed, 08 Nov 2006 21:42:43 GMT

THIS IS NOT THE ENTIRE SOURCE, ONLY KEY SNIPPETS.

public void OnMouseRightButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs args)

{

Point mouseposition = args.GetPosition(vp);

PointHitTestParameters pointparams = new

PointHitTestParameters(mouseposition);

//test for a result in the Viewport3D

VisualTreeHelper.HitTest(vp, null, HTResult, pointparams);

}

public HitTestResultBehavior HTResult(System.Windows.Media.HitTestResult rawresult)

{

RayHitTestResult rayResult = rawresult as RayHitTestResult;

if (rayResult != null)

{

RayMeshGeometry3DHitTestResult rayMeshResult = rayResult as RayMeshGeometry3DHitTestResult;

if (rayMeshResult != null)

{

GeometryModel3D hitgeo = rayMeshResult.ModelHit as

GeometryModel3D;

UpdateMaterial(hitgeo);

}

return HitTestResultBehavior.Continue;

}

public void UpdateMaterial(GeometryModel3D gm3d)

{

VisualBrush VB = new VisualBrush();

if (material1)

{

material1 = false;

VB.Visual = UI2Contents;

}

else

{

material1 = true;

VB.Visual = UI1Contents;

}

DiffuseMaterial myDiffuseMaterial = new DiffuseMaterial(VB);

MaterialGroup mg = new MaterialGroup();

mg.Children.Add(myDiffuseMaterial);

gm3d.Material = mg;

}