var rectangle;

function createPrimitives(scene) {
    rectangle = scene.primitives.add(new Cesium.Primitive({
        geometryInstances : new Cesium.GeometryInstance({
            geometry : new Cesium.RectangleGeometry({
                rectangle : Cesium.Rectangle.fromDegrees(-120.0, 20.0, -60.0, 40.0),
                vertexFormat : Cesium.EllipsoidSurfaceAppearance.VERTEX_FORMAT
            }),
            attributes: {
                color: Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.RED.withAlpha(0.8))
            }
        }),
        appearance : new Cesium.PerInstanceColorAppearance(),
        allowPicking: false
    }));
}
var viewer = new Cesium.Viewer('cesiumContainer');
var scene = viewer.scene;
scene.globe.depthTestAgainstTerrain = true;
scene.logarithmicDepthBuffer = false;

viewer.useDefaultRenderLoop = false;

setInterval(() => {
    scene.pick(new Cesium.Cartesian2(530, 400), 10, 10);
    scene.render();
}, 30);

createPrimitives(scene);