Since the early days of Cesium, there has been interest in OpenLayers/Cesium interoperability. Good news, the OL3 folks just released OL3-Cesium. Check out
I have not personally developed with this, but am happy to see it and curious to see what folks think.
Patrick
Hi Patrick,
Live examples are available at
http://openlayers.org/ol3-cesium/examples/
There is also some WIP on the 2D / 3D transition at
http://dev.camptocamp.com/files/gberaudo/ol3-cesium-demo/examples/gmap.html
Guillaume Beraudo
Camptocamp Engineer
Looks awesome. Is there any more information avaible? blog posts or announcements. is the code on github 
Hi Poul,
The source is on github at https://github.com/openlayers/ol3-cesium .
Camptocamp announcement is at http://www.camptocamp.com/en/actualite/ol3-cesium-open-source-release/
Guillaume Beraudo
Camptocamp Engineer
Thanks. Looks very interesting.
What projections are supported? epsg:3857/4326, any custom projections ? I guess its limited to what cesium supports (my knowledge on cesium is limited as of now).
What is the general idea behind it. Take all sources/layers configured in ol3 and wire them up in cesium on the fly?
And again, just vent over the examples, really awesome work guys. Big Thumbs up.
Hi,
Cesium supports raster layers in EPSG:3857 and EPSG:4326; Ol3-Cesium
will automatically synchronize layers in these projections.
Other projections will only be visible in the Ol3 map. However, adding
an equivalent layer to the Cesium scene will do the trick.
Vector layers are always reprojected on the fly from the Ol3 map
(any projection) to EPSG:4326 and may be positioned in 3D.
Creating and configuring a Cesium globe from an Ol3 map is an important
task. Then there is also shared selection, view/camera synchronization...