It works, but when I get the buffer, the antialiasing hasn't been applied to the frame yet, and I can get only bad quality snapshots.
I thought that can set a timer to wait about half a second before getting the snap, but it's not 100% reliable and pretty ugly code :-)
How can I intercept a sort of event "Antialising applied", if it exists?
There is no special event signaling the completion of antialiasing. But you can wait for 8 cycles of rendering and grab a buffer with antialiased picture. Note, that this works if the scene was completely "static" during these 8 frames; that is, there was no events fired/processed.
To count frames passed, you can implement IVRMLGeneralCallback and register it as a service in the Engine. The Engine will call back the IVRMLGeneralCallback::OnFrame() method after every rendering cycle.
[Antialiasing] Snapshot issue