3D world position to screen space coordinates

Customization
1

Hi there.

So I am using the viewer api and I would like to get the 2d screen coordinates of a 3d location in the scene.

I am not finding anything in the docs, is there a way of getting this info?
I can’t seem to use the THREE js matrixWorld of the objects since they are always ‘null’

Thanks in advance!

2

Do you use Viewer.onNodeTypeClicked? This callback doesn’t include such information. Maybe try adding your own mouseup, touchend event handlers, store the screen position passed by a web browser to these handlers, and then in onNodeTypeClicked use the stored values.

3

I was going with that approach now but it felt a bit “hacky”.

I am indeed using the onNodeTypeClicked and thus get the 3d position.
Thought there was maybe an existing way of converting to screen position.

Thanks for answering!

4

This does help me to get the 2d position once when I click.
But I also want when I’m moving around in the scene to get the updated screen position for that 3d position.

So that’s why I was looking for a 3d to 2d method

5

Unfortunately, Shapespark doesn’t have an API for this. This would require taking into account current camera position and projection matrix.

1 Like
6

I see

There is the Viewer.getCameraPosition() that I can use to get the camera position.
But is there a way to get the projection matrix as well from the camera?

7

No, projection matrix is not available.