My video bus track is empty. Is that normal? I'd love to get a preview of the output in it, but perhaps I've misunderstood what it's for. Can anyone help?
Yes, it's normal. You already hava a preview window :). On the video bus track you control Mute, Fade to Color, Motion Blur and Supersampling. It is easier to control these things over time when you have a track to do it on. Right click it and see for yourself. You can also make some additional things in the track header and use it to put FX on the whole output, as if you dropped an FX on the preview window. Open the help or look in the manual for full information on this. There's also an audio bus track where you control the master audio outputs Mute, Volume and Pan.
I think it would be a great idea to to have a toggle to be able to display a rough preview of the expected rendered video output on the video bus track, as frames exactly like on the individual video tracks. I don't think this would be asking too much of most user's computers and it would be a great "quick see" to check you've got things about rright (e.g. titles, composites etc). If you got annoyed by any delays that was causing on a complicated project you could just switch if off. What do you think?
Yes, I understand what you mean. I think though, that such a function would require the timeline to be rendered. You can in the events themselves roughly display video, the more zoomed in you are the more accurate it becomes. Vegas renders to the preview window on the fly and does not work with "background rendering" as some other applications do. And if it renders on the fly, how will it know what things will look like up ahead? I've seen a couple of users wish for background rendering though, maybe it'll be there some day. Or maybe there's another way of doing this in the Video Bus Track, these are just my thoughts.
Yes, it would require some background "preview rendering" of a similar quality to the preview window. I imagine the preview frames wouldn't appear instantly in the video bus track. They'd kind of fill up from the left as they were rendered. But it would make a great "look see" to check your compositing and such like. I think it would important to be able to turn it off if a user doesn't want it to save system resources.