没有关闭PointPrimitive的深度写入:

关闭了PointPrimitive的深度写入:

 if (pointPrimitiveCollection._rsOpaque) {
        pointPrimitiveCollection._rsOpaque = Cesium.RenderState.fromCache({
          depthTest: {
            enabled: false,
          }
        });
      }

 const p = pointPrimitiveCollection.add({
            position: cartesian,
            pixelSize: 50,
            color: Cesium.Color.RED
          })
 // 还是会深度写入,只不过写入的是-1         
 p.disableDepthTestDistance = Number.POSITIVE_INFINITY;