Physics Helper for Blend, Silverlight, WP7 and Farseer

New Post: How to add PhysicsMagnetBehavior

MattWilsonMD — Mon, 06 May 2013 20:28:27 GMT

I'm new to the Helper Library and CANNOT figure out what seems like it should be so simple. How do I apply the Magnet behavior? What am I missing?

Here's what I am working with:

    <Canvas x:Name="LayoutRoot" Background="White">
        <i:Interaction.Behaviors>
            <pb:PhysicsControllerBehavior MousePickEnabled="True"/>
        </i:Interaction.Behaviors>
        <Rectangle x:Name="floor" Fill="Black" Height="90" Canvas.Left="-36" Stroke="Black" Canvas.Top="421" Width="701">
            <i:Interaction.Behaviors>
                <pb:PhysicsObjectBehavior IsStatic="True"/>
            </i:Interaction.Behaviors>
        </Rectangle>
        <Ellipse Fill="#FF898989" Height="54" Canvas.Left="185" Stroke="Black" Canvas.Top="164" Width="54">
            <i:Interaction.Behaviors>
                <pb:PhysicsObjectBehavior RestitutionCoefficient="0.5" Mass="1"/>
            </i:Interaction.Behaviors>
        </Ellipse>
        <Rectangle x:Name="rectangle" Fill="#FF898989" Height="187" Canvas.Left="279" Stroke="Black" Canvas.Top="218" Width="75">
            <i:Interaction.Behaviors>
                <pb:PhysicsMagnetBehavior MaxDistance="500"/>
                <pb:PhysicsObjectBehavior Mass="5"/>
            </i:Interaction.Behaviors>
        </Rectangle>
    </Canvas>

New Post: Add behavior to a Body by code

StepTNT — Mon, 18 Feb 2013 13:24:16 GMT

I've got this code

            playerBody = BodyFactory.CreateBody(world);

            CircleShape playerShape = new CircleShape(ConvertUnits.ToSimUnits(playerTexture.Width / 2f), 5f);
            
            Fixture playerFixture = playerBody.CreateFixture(playerShape);
            playerBody.BodyType = BodyType.Dynamic;
            playerBody.Position = ConvertUnits.ToSimUnits(new Vector2(viewport.Width / 2f, viewport.Height / 2f));
            playerBody.Restitution = 0.8f;

taken from a tutorial and I'd really like to allow mouse picking on playerBody.

I know how to do it with XAML but I can't do it in C#!

I'm trying with

            PhysicsControllerBehavior pcb = new PhysicsControllerBehavior();
            pcb.MousePickEnabled = true;
            pcb.Attach(playerBody);

but, of course, it won't even compile as the Attach method expects a DependencyObject.

How can I do it?

Thanks

New Post: Physics Helper and target WP8

runesel — Tue, 22 Jan 2013 09:20:28 GMT

The question is now answered here:
http://physicshelperxaml.codeplex.com/discussions/428729

Rune

New Post: Question about Gravity

AndyBeaulieu — Tue, 15 Jan 2013 16:11:59 GMT

This forum is for the "original" Physics Helper for Silverlight and Blend, which uses Behaviors.

Perhaps you are using the "newer" Physiscs Helper XAML project from here - http://physicshelperxaml.codeplex.com/ ??

If so, then you want to use the Simulator on the PhysicsCanvas object.

New Post: Question about Gravity

Jundai — Tue, 15 Jan 2013 15:23:08 GMT

Wait...

Is this C# plus xaml?

Which reference has PhysicsControllerMain?

New Post: Question about Gravity

Jundai — Tue, 15 Jan 2013 14:22:34 GMT

I try it now

New Post: Question about Gravity

AndyBeaulieu — Tue, 15 Jan 2013 14:15:06 GMT

Please be sure to set the properties on the Simulator, not the behavior. Note the red text below, it is using the Simulator object on the physics controller.

PhysicsControllerMain _physicsController = cnvGame.GetValue(PhysicsControllerMain.PhysicsControllerProperty) as PhysicsControllerMain;

{...}

Vector2 newVector = new Vector2();

newVector.X = 0;
newVector.Y = 10;

_physicsController.Simulator.Gravity = newVector;

New Post: Question about Gravity

Jundai — Tue, 15 Jan 2013 13:59:54 GMT

I have tried to set GravityHorizontal and GravityVertical both zero.

But doesn't make any changes...

New Post: Question about Gravity

AndyBeaulieu — Sat, 12 Jan 2013 23:06:36 GMT

Hello :)

Please see this post, which shows setting gravity at runtime - http://physicshelper.codeplex.com/discussions/277222

New Post: Question about Gravity

Jundai — Sat, 12 Jan 2013 04:50:04 GMT

Hello? Helloo?

New Post: Question about Gravity

Jundai — Wed, 09 Jan 2013 05:55:08 GMT

Hi,

I'm a student using physics helper for the first time. I've done a few things but now I'm having problems with gravity. I want to turn off gravity to create a block-out application.

I've tried setting the HorizontalGravity and VerticalGravity of the physics canvas to zero, but a ball I create within the canvas still behaves as if gravity is acting upon it.

How can I turn off gravity within a physics canvas so that all objects within that canvas no longer act as if gravity as acting upon them?

Thanks for your help.

New Post: Physics Helper and target WP8

runesel — Mon, 31 Dec 2012 02:41:30 GMT

Is it possible to use Physics Helper in VS 2012 (Express) on a Win 8 PC and target WP8? I have some WP7 games (that use Physics Helper) with performance issues on WP8 that I want to retarget to WP8 - and then test performance.

Or is my best shot to use physicshelperxaml? I do not see any WP8 sample in physicshelperxaml...

Would have testet this myself, but do not have the Win8/WP8 dev environment up and running yet :)

Rune

New Post: Path to Body

conehead — Tue, 04 Dec 2012 19:38:18 GMT

I'm trying to make a level editor where you can draw the objects. It works fine if I draw an object where the 2 ends meet like a square or circle. But if I draw just a line it doesn't create the physics object. I've tried a lot of different ways but couldn't get it to work. Here is how I'm trying to do it. Any help would be great.

Path p = getPathFromStroke(stroke);
               
                CnvGame.Children.Add(p);
              
                BehaviorCollection bc1 = Interaction.GetBehaviors(p);
                PhysicsObjectBehavior b1 = new PhysicsObjectBehavior();
                b1.IsStatic = true;
                b1.FrictionCoefficient = .01;
                bc1.Add(b1);
                PhysicsObjectMain m1 = (PhysicsObjectMain)p.GetValue(PhysicsObjectMain.PhysicsObjectProperty);
                _physicsController.AddPhysicsBody(m1);

New Post: Jitter

RonakDave — Thu, 29 Nov 2012 08:00:08 GMT

Hi Guys,

I am an absolute beginner at this so perhaps my question may seem dumb but please bear with me.

I am using Windows 8, VS2012 Express for Windows 8, Blend 5

I have created a physics canvas

<ph:PhysicsCanvas x:Name="RootAnimationCanvas" MousePickEnabled="True" DebugMode="False" >

</ph:PhysicsCanvas>

Sprites

<ph:PhysicsSprite x:Name="PlanetObj" Canvas.Top="400" Canvas.Left="700" ShapeType="Polygon" Width="240" Height="80" RestitutionCoefficient="0"><Path Data="M0.5,1.252 L398,0.5 L202,300.5 z" Fill="Red" Canvas.Left="0" Stroke="#FF000000" Canvas.Top="0" UseLayoutRounding="False"/></ph:PhysicsSprite>

<ph:PhysicsSprite x:Name="PivotPoint" Canvas.Top="388" Width="10" Height="10" Canvas.Left="656" ShapeType="Ellipse" IsStatic="True"><Ellipse x:Name="Circle" Height="10" Width="10" Canvas.Top="0" Canvas.Left="0" Fill="Aqua"/></ph:PhysicsSprite>

And also a Joint

<ph:PhysicsJoint x:Name="Point" Canvas.Top="388" Canvas.Left="656" BodyOne="PivotPoint" BodyTwo="PlanetObj" CollisionGroup="1"/>

All these elements are inside the canvas

But now the issue I have is that when the object comes to near slowing down it starts to jitter and and vibrate.

I have also set the root canvas gravity to zero

RootAnimationCanvas.Simulator.Gravity.Y = 0;

RootAnimationCanvas.Simulator.Gravity.X = 0;

Just in case I also set the forces to clear.

RootAnimationCanvas.Simulator.ClearForces();

Please help guys =)

New Post: Cannot create an instance of physicscanvas

AndyBeaulieu — Thu, 01 Nov 2012 21:18:49 GMT

It looks like you are using the newer (Windows 8, WP) version of Physics Helper XAML from here - http://physicshelperxaml.codeplex.com/

This forum is for the original Physics Helper which uses Behaviors.

At any rate, you should make sure that you have an xmlns at the top of the xaml, like this:

xmlns:ph="using:Spritehand.FarseerHelper"

New Post: Cannot create an instance of physicscanvas

snehasawant — Thu, 01 Nov 2012 13:38:22 GMT

I have just started with physics helper and I followed the steps as per mentions in the documentation.

I added the following in xaml

"<Canvas x:Name="cnvGameOuter" >

    <ph:PhysicsCanvas x:Name="cnvGame" Background="Blue" Width="1366" Height="768" MousePickEnabled="true">

        <ph:PhysicsSprite x:Name="block" Canvas.Left="200" Canvas.Top="0" Width="100" Height="100" >
            <Rectangle Width="100" Height="100" Fill="Red" />
        </ph:PhysicsSprite>

        <ph:PhysicsSprite x:Name="ground" Background="DarkGreen" Canvas.Left="0" Canvas.Top="648" Width="1366" Height="120" IsStatic="True" />

    </ph:PhysicsCanvas>

</Canvas>"

its giving me an error as cannot create an instance on PhysicsCanvas. What is the solution for it??

Source code checked in, #81799

Project Collection Service Accounts — Mon, 01 Oct 2012 21:57:23 GMT

Upgrade: New Version of LabDefaultTemplate.xaml. To upgrade your build definitions, please visit the following link: http://go.microsoft.com/fwlink/?LinkId=254563

Source code checked in, #81798

Project Collection Service Accounts — Mon, 01 Oct 2012 21:51:05 GMT

Checked in by server upgrade

New Post: Objects passing through one another at high velocity

conehead — Wed, 19 Sep 2012 13:02:39 GMT

nkast wrote:

conehead wrote:

I'm having same issue. The oncollision event is firing it just isnt bouncing off the wall.

@conehead
What you are describing is entiry another problem and completly unrelated to high velocities. My quess is that you are telling farseer to ignore the collision inside the onCollision handler.
Please start a new thread and provide a sample project of how you hook the onCollision event.

I don't know much about Physicshelper & SL, since i work directly on farseer in XNA. All I can tell you is that in farseer the onCollision handler returns a boolean, if your handler returns false then this tells farseer to ignore the collision.

In order to not confuse others, let me sum that the problem described by @Spruce can be solved by:

A) enabling the Continues Collision Detection (CCD)
 Settings.ContinuousPhysics = true;
B) set IsBullet to every element with high velocities
<pb:PhysicsObjectBehavior IsBullet="True"/>
CCD will have an impact on performance, so you shouldn't use it if you don't need it.

This seem to help. It appears(before adding continuous physices) that when the collision fired it was already on the other side of my wall.

New Post: Objects passing through one another at high velocity

AndyBeaulieu — Wed, 19 Sep 2012 11:39:40 GMT

For the oncollision event and no bouncing, try setting DebugMode="true" on the PhysicsController. This will show your object's boundaries (it's possible that one of the boundaries is not what you want/expect.