How to pick position in COLUMBUS_VIEW

CesiumJS
1

Hi, everyone

I try to use scene.pickPosition() to get height of a 3D model and succeeded in 3D view.

But when morph to COLUMBUS_VIEW, it failed.

I want to know are there any other way to get height of a 3D model in COLUMBUS_VIEW?

thanks.

Chris

2

Hello,

It looks like pickPosition is currently only supported in 3D. I created an issue here so we know to look into it in the future: https://github.com/AnalyticalGraphicsInc/cesium/issues/4084

Sorry, but I’m not sure of any way to get the model height from Columbus view at this time.

It’s a bit more difficult to compute due to the projection of the map.

Best,

Hannah

3

Thanks Hannah, I find there is a function SceneTransform.wgs84ToWindowCoordinates().

It can transform cartographic coordinates into window position,

Can it be reversed to compute wgs84 coordinates from window position?

Chris

在 2016年7月5日星期二 UTC+8下午9:28:29，Hannah Pinkos写道：

4

Hi Chris,

If you take a look at our picking demo: http://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=Picking.html&label=Showcases

You can use the scene.pickEllipsoid function to convert a window position to a world coordinate. That won’t give you the height of a model though, it only gets the globe position.

You can try using camera.getPickRay. I know this works with getting the height of terrain, but I’m not sure if it works with 3D models

Here is a code sample:

var ray = viewer.camera.getPickRay(click.position);
var position = viewer.scene.globe.pick(ray, viewer.scene);

``

Best,

Hannah

5

Thanks Hannah, I tried the camera.getPickRay() function but it can not get the height of 3d model.

The ray goes through the model and intersect with the globe. And the coordinates go wrong after the view changes to Columbus view.

Best,

Chris

在 2016年7月6日星期三 UTC+8下午9:22:52，Hannah Pinkos写道：

6

Hi Chris,

Thanks again for the report. 2D and Columbus View support for scene.pickPosition were added in #4990. They will be in Cesium 1.31 on March 1.

Patrick