Cesium Entity Ellipse Image strotation cause distortion

Hi,

I've recently been testing rendering 5000 ellipse entities on the 3d globe. I set each ellipse entity's image that shows a green Arrow that points north.Then I set its strotation value to show where the arrow is pointing.
From observation, almost all ellipses' image appears alright and accurate to its rotation. However, I spotted some with distorted images where the arrow head somehow fuses with another arrow head from opposite direction.

I ventured to a thread- https://groups.google.com/forum/#!topic/cesium-dev/UF9wQugwRf0, that seems to be similar in coding code but it didn't solve the problem i'm having. The only difference in the code is I'm using image URL path, not canvas.

Using Cesium 1.20
Win 7 Pro
Chrome

Thanks and Regards
Cal

Hello Cal,

I don’t quite understand what you’re seeing. Can you paste a code sample or a screenshot?

Best,

Hannah

Hi Hannah,

This is the code sample I've tested.

var entity = viewer.entities.getOrCreateEntity("test");
        var ellipseGraphics = new Cesium.EllipseGraphics({
            semiMajorAxis: 5000,
            semiMinorAxis:5000,
            material: new Cesium.ImageMaterialProperty({
                image:'images/image.png',
                color: new Cesium.Color(1.0, 1.0, 1.0, 0.99)
            }),
            rotation : Cesium.Math.toRadians(-168),
            stRotation : Cesium.Math.toRadians(168),
            granularity: Cesium.Math.toRadians(10) //Less computation due to vertices
        });

        entity.ellipse = ellipseGraphics;
        entity.position = Cesium.Cartesian3.fromDegrees(1.54495, 44.94759);

        var entity2 = viewer.entities.getOrCreateEntity("test2");

        entity2.ellipse = ellipseGraphics;
        entity2.position = Cesium.Cartesian3.fromDegrees(1.52278, 45.00838);

        viewer.zoomTo(viewer.entities);

Regards
Cal

Thanks Cal! It looks like this is a bug in Cesium. The image is being drawn incorrectly on one of the corners of the geometry. I’ve filed an issue here: https://github.com/AnalyticalGraphicsInc/cesium/issues/3851

Best,

Hannah

Hi Cal,

We tested this issue in Cesium 1.26 and it appears to be fixed: https://github.com/AnalyticalGraphicsInc/cesium/issues/3851

Let me know if you can still reproduce this.

Thanks!

Hannah