public static Geometry createGImpactTestFloor(AssetManager assetManager, float floorDimensions, Vector3f position) {
        Geometry floor = createTestFloor(assetManager, floorDimensions, position, ColorRGBA.Red);
        RigidBodyControl floorControl = new RigidBodyControl(new GImpactCollisionShape(floor.getMesh()), 0);
        floor.addControl(floorControl);
        return floor;
    }
Creates a curved "floor" with a GImpactCollisionShape provided as the RigidBodyControl's collision
shape. Surface has four slightly concave corners to allow for multiple tests and minimize falling off
the edge of the floor.

@param assetManager for loading assets
@param floorDimensions width/depth of the "floor" (X/Z)
@param position sets the floor's local translation
@return a new Geometry
jme3-examples/src/main/java/jme3test/bullet/PhysicsTestHelper.java