Need some help/advice on creating a "composite" Renderable

[kook04]

Hey all. Hopefully someone has some insight on accomplishing what I'm trying to do. Basically, I'm trying to create a custom Renderable class which is made up of multiple existing World Wind Renderables. In this example, a SurfaceIcon and a GlobeAnnotation.

I'm essentially trying to create a labelled icon, which I can further customize one I get the basics figured out.

My methodology is as follows, but it's not working completely.

Create a new MapItem class which implements Renderable and Movable. This MapItem class encapsulates both a SurfaceIcon and GlobeAnnotation. The MapItem is constructed with a Position, which is passes through to both the icon and annotation.

As far as the methods of the Renderable and Movable interfaces go, I just pass the appropriate parameters through to both of the objects held withing (icon and annotation).

When I do this, only the GlobeAnnotation is showing up on the map. Any ideas?

Thanks.

[dcollins]

Are you forwarding the preRender call to SurfaceIcon?

[pabercrombie]

You're on the right track, but you also need to implement PreRenderable. Implement preRender to call preRender on the SurfaceIcon. (Things drawn on the surface of the globe need to be assembled before the scene is rendered. If you call render on the SurfaceIcon without calling preRender, it won't draw anything.)

[tag]

Take a look at OSMWayShape in the new openstreetmap package of worldwindx.

[kook04]

Thank you all for your responses! The PreRenderable interface was the issue. I had no idea it existed. Once I implemented that in my custom class and forwarded calls to the SurfaceIcon, the icon started showing up.

Thanks again.