public override void PreSolve(Contact contact, Manifold oldManifold) { base.PreSolve(contact, oldManifold); Fixture fixtureA = contact.FixtureA; Fixture fixtureB = contact.FixtureB; if (fixtureA == m_platform) { contact.SetTangentSpeed(5.0f); } if (fixtureB == m_platform) { contact.SetTangentSpeed(-5.0f); } }