BulletPhysics (.net) Can't seem to get collisions working

[pixartist]

Hi, I'm working with the .net binding of Bullet and I can't seem to get the physics working properly. I use this to start the physics engine:

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var collisionConfig = new BulletSharp.DefaultCollisionConfiguration();
            PhysicsWorld = new BulletSharp.DiscreteDynamicsWorld(
                new BulletSharp.CollisionDispatcher(collisionConfig), 
                new BulletSharp.DbvtBroadphase(), 
                new BulletSharp.SequentialImpulseConstraintSolver(), 
                collisionConfig);

Now I add some cubes like this:

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public void SetCollisionBox(Vector3 center, Vector3 scale)
		{
            SetBody(new BoxShape(0.5f), center, scale);
		}

private void SetBody(CollisionShape shape, Vector3 center, Vector3 scale)
		{
			Center = center;
			ClearBody();
            RigidBodyConstructionInfo info = new RigidBodyConstructionInfo(1, new DefaultMotionState(Matrix4.CreateTranslation(Transform.Position) + Transform.Rotation.ToMatrix4()), shape);
			Body = new RigidBody(info);
            Body.CollisionShape.LocalScaling = scale;
            
            GameObject.App.PhysicsWorld.AddRigidBody(Body);
		}

Now these cubes seem to at least collide with each other and are certainly affected by gravity. But I wanted to create a baseplate (a cube) with static behaviour, using this method:

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public void MakeStatic()
        {
            if (Body != null)
                Body.SetMassProps(0, Vector3.Zero);
        }

And the cubes are just falling through. What am I missing ?

[anthrax11]

Matrices should be multiplied, not added.
new DefaultMotionState(Matrix4.CreateTranslation(Transform.Position) * Transform.Rotation.ToMatrix4()

I tried adding translation and rotation matrices in BulletSharp and the effect was indeed that it looked the same visually, but there were no collisions because the matrix was somehow messed up and was confusing the physics engine.

[pixartist]

Ha, I'm an idiot. Thanks, that was my mistake!