I have a selection of billboards rendered on a globe and now I'd like to display an HTML dialog beside them when clicked. I've worked out the click handling part but I've become stuck when it comes to positioning to content.
My questions are:
1. How do I calculate the screen-space coordinates of a billboard so that I can correctly align the dialog box? Simply using the position of the click event doesn't work because I need to connect each dialog box to the exact center point of its billboard with an SVG line, hence I need the screen position of the billboard itself.
2. Secondly, I need to remove the active dialog box when the map is rotated/zoomed etc. I'm aware of ScreenSpaceEventHandler but this only gives access to the raw input events - are there any higher level camera events that I can tap into, or do I have to infer camera motion motion from the raw events?
Thank you for your time,