Scene.pick and obtaining position of picked entity

CesiumJS
1

Hi,

I am using the last version of cesium with the GeoAdmin Terrain with 3D tiles as in this code pen.

I am trying to pick an object (i.e., a 3D building in this case) using scene.pick.

If I follow the example in the sandbox to pick a feature it works fina and I am able — for example — to change the color of the hovered entity.

For further queries, however, I need to get the position (i.e., the center of the bounding box) of the picked entity/feature.

I tried in many ways, but I did not succeed. Is there any known solution for this? Should I use scene.pickPosition or is there any other way to accomplish this? I was expecting a way to get the position of the pickedFeature directly.

Best regards and thanks in advance!

Roberto

2

It isn’t possible to get the position or bounding volume of the feature, but yeah, you can use scene.pickPosition to get the exact location where the mouse picked.

3

Thank you Sean.

I find it strange that I cannot get the bounding volume of the feature but I can change its color :S

scene.pickPosition returns the position where the mouse picked, thus, in case I pick a feature (say, a building) I get a position that ‘touches’ one of the walls of the picked building. Am I right?

Best,
R

4

So, you all confirm that — besides using scene.pickPosition and obtain the position where the mouse picked — there is no way to access the bounding volume of the picked feature.

I need to check whether a given point is inside the bounding volume of the picked feature. Is there any known way to achieve this?

Cheers and thanks in advance,

Roberto

5

The Cesium3DTileset feature does not have the underlying model information tied to the object. So no, there is currently no way to retrieve the model itself from a pick that I’m aware of.

6

Roberto - keep an eye on https://github.com/AnalyticalGraphicsInc/3d-tiles/issues/127.

The bounding volume information would have to be embedded in the tile in some way - it is not easy to synthesize at runtime right now.

7

Thank you, I am following the issue now.

To me it looks strange only because I can easily invoke .color and change the color of the feature, but I cannot retrieve, say, its geometry.

Best,

Roberto

8

Yeah, geometry is tougher because we offload that to GPU memory so its not easily accessible, whereas colors are stored on the CPU and updated on the GPU as textures. It’s a different kind of problem.

9

Sean,

Is there anyway to get the surface normal of the picked position?

-DC

10

Sorry I missed your other thread, I responded to this here:

https://groups.google.com/d/msg/cesium-dev/RyK1q3jdfgo/_7-togSbAQAJ