jagged lines

1. A concise explanation of the problem you're experiencing.

I create lines with SimplePolylineGeometry(), but they are very jagged. How do I make them look smooth. It seems antialiasing is on by default.

2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.

var geom = new Cesium.SimplePolylineGeometry(
{
    positions: newPoints,
    vertexFormat : Cesium.PerInstanceColorAppearance.VERTEX_FORMAT,
    perPositionHeight: true,
    width: 1
});
var inst = new Cesium.GeometryInstance(
{
    geometry : geom,
    attributes : {
       color : Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.BLACK)
    }
});

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

Make my model look good....

4. The Cesium version you're using, your operating system and browser.

Sandcastle.

PS I am using chrome, version 72, 64 bit

This is a good thread on toggling FXAA in Cesium:

https://groups.google.com/forum/#!msg/cesium-dev/XXXBFSYgb7s/FaBmLYhyCAAJ

Let me know if it helps. If not, if you have screenshots or a Sandcastle example I can run as well that would help.