no bounce

[wizzy123]

Hi,

first of all great product!

I have nodified the BasicSetupDemo source to have a couple of bars fall down on top of each other. To problem is that the last bars jump up (bounce). Is it possible to suppress this?
I know that there are a lot of settings that I can tweak the physics with ...

in the BasicSetupGame.cs i have nodified this:

LoadContent() methode
Remove:

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space.add(new Box(new Vector3(0, 4, 0), 1, 1, 1, 1));
space.add(new Box(new Vector3(0, 8, 0), 1, 1, 1, 1));
space.add(new Box(new Vector3(0, 12, 0), 1, 1, 1, 1));

Replace with:

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			//Create bars
			float Height = 5;
			bool Switch = true;
			int mass = 1;
			float Size = 1;
			float Space = 0.25f;
			float lengte = Size * 3 + Space * 2;
			for (int iCounter = 1; iCounter < 5; iCounter++)
			{
				if (Switch)
				{
					space.add(new Box(new Vector3(0, Height, 0), 1, 1, lengte, mass));
					space.add(new Box(new Vector3(1.25f, Height, 0), 1, 1, lengte, mass));
					space.add(new Box(new Vector3(2.5f, Height, 0), 1, 1, lengte, mass));
				}
				else
				{
					space.add(new Box(new Vector3(1.25f, Height, 1.25f), lengte, 1, 1, mass));
					space.add(new Box(new Vector3(1.25f, Height, 0), lengte, 1, 1, mass));
					space.add(new Box(new Vector3(1.25f, Height, -1.25f), lengte, 1, 1, mass));
				}
				Height += 3f;
				Switch = !Switch;
			}

I have have added

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box.collisionMargin = 0f

in the foreach loop.

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			foreach (Entity e in space.entities)
			{
				Box box = e as Box;
				if (box != null) //This won't create any graphics for an entity that isn't a box since the model being used is a box.
				{
					box.collisionMargin = 0f;
Matrix scaling = Matrix.CreateScale(box.width, box.height, box.length); //Since the cube model is 1x1x1, it needs to be scaled to match the size of each individual box.
					//Add the drawable game component for this entity to the game.
					Components.Add(new EntityModel(e, cubeModel, scaling, this));
				}
			}

[Norbo]

The BasicSetupDemo is currently running under an earlier version of BEPUphysics, since the covered material hasn't changed. However, the newest version of BEPUphysics may provide better behavior.

As far as other tweaks go, most of the bounce in the newest version of the engine is related to position correction. When objects interpenetrate, the engine applies an extra push to get them apart. In tall stacks, this small bounce can propagate into a larger one. The speed and strength of this push can be changed using these settings:

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space.simulationSettings.collisionResponse.maximumPositionCorrectionSpeed
space.simulationSettings.collisionResponse.penetrationRecoveryStiffness

To keep things from slowly sifting through each other, some amount of position correction is necessary, so I wouldn't recommend totally turning it off.

I strongly recommend not reducing the collision margin to 0. It won't change the bounce much (if any), and collision margins are required for some collision detection systems to be efficient. More information can be found here: http://www.bepu-games.com/forums/viewto ... 409&p=4181