my method of detecting if a cartographic point is in the view

CesiumJS
1

Hi

I’m using SceneTransforms.wgs84ToWindowCoordinates and pointInsideTriangle to detect a cartographic point in the view,

but when the point is in the back hemisphere of the earth, this method can also return a windowposition,

Such result will influence the detection, I want to know if there is a solution or a better way to detect if a point is in the view.

Chris

2

You can check if a point is hidden on the other side of the earth using the EllipsoidalOccluder. Note occluder.isPointVisible takes Cartesian3 not cartographic:

var occluder = new Cesium.EllipsoidalOccluder(Cesium.Ellipsoid.WGS84, camera.position);

occluder.isPointVisible(positionInCartesian3)

Here is some previous post that maybe helpful:

https://groups.google.com/forum/#!searchin/cesium-dev/How$20to$20get$20the$20extent$20of$20the$20current$20camera$20position/cesium-dev/e2H7EefikAk/OhEXBtn5yc0J

https://groups.google.com/forum/#!searchin/cesium-dev/ComputerVisibility$20/cesium-dev/dmp2hjU9zBs/L-E3cq3oAWoJ

3

Thanks, Tim

That helps a lot. I will try this method.

Chris

在 2015年11月28日星期六 UTC+8上午7:02:35，TimH写道：

4

Hi Tim

I have try your method and it works perfectly.

Thanks a lot !

Chris

在 2015年11月28日星期六 UTC+8上午7:02:35，TimH写道：