But if you mean file -save/save as, it's everything in the project.

If I understand this right:

* "save as" a new timeline name
* Then remove delete the elements you do not want in your "part of a project"
* Then "save as" again, but check the copy media check box, and save to a new folder.

Take a large project and use the split command to arbitrarily slice a wedge of the project apart. Delete the split before and after sections if they are applicable and leave the desired wedge on the timeline. Perhaps your arbitrary split leaves some tails of unwanted media - delete those. Now align the wedge unit left to the left edge of timeline and save.
Result you have a section of a larger project saved into its own project.

If you use the cursor and click+drag to select an area of the project, hitting the "delete" key should have the same result.

There is some difference in approach between feeling the need to create a real separate .veg project file, or choosing to extract a timeline segment as a digital intermediate for further use. It pays to know what you expect and what you want to happen later on. For me, I would do both operations if it is a valuable part of a project.

I think there are much easier ways to do what the OP wants, namely to save a portion of the project rather than render a portion of the project.

1. First approach. Open a second instance of Vegas. Select all the events on all timelines, but only within the section you want to save. Select "Copy" from the Edit menu. Switch to the second instance of Vegas, and select "Paste" from the Edit menu.

This approach will only work if all your editing is contained only within the events, and only with points you've added to volume envelopes, etc. The approach will NOT work if you have various things (fX, track motion, compositing) applied to the track or project controls, or to media. So, if it works, it will work well, but it is limited.

2. Second approach. Use nested VEG files. To do this, drag the VEG file from your project to the timeline in a new, blank Vegas project. Match the project properties to the VEG file, and then edit this VEG file as if it were a video file. Save that project. This will give you an edited version (a subset) of the original project, but without taking the time, disk space, and quality loss involved in rendering.

There are a few limitations of this approach: any changes in the original project will propagate to the edited version. If you don't want this to happen, than save the original project under a new name after you create your new project, and that way any future edits to the original project will not appear in the shorter version.

The other limitation is that you will no longer have access to any of the original media or any of the fX, compositing, track motion, envelopes, etc. that are in the original project.

3. Third approach. Save the project under a new name, and then delete the portions you don't want. This was already suggested above. This is the "ultimate" approach because you won't have any of the limitations or compromises of the previous two approaches, but it may take quite a bit of time to delete the portions of the project you no longer need. If you do take this approach, make sure to rename the project (use Save As) before you start deleting.

The only downside I can think of with this third approach is that if you still need to maintain a link to the changes you make to the original full-length version of the project, you will no longer have those links.

With all due respect to johnmeyer - the 1 and 2 approach to this problem are really plagued with gotchas. If the parent project is simple and that is all you want to do, then maybe use it, but don't get ready to try this on full-fledged projects because it won't work. Approach 3 which is the context of what I previously outlined is the universal approach that will work in all instances. Use it and get used to using it.

As far as documenting the project elements - I use Timeline Tools to do this and naming all project tracks - this kind of internal documentation style will stay with the new sub-project file if using approach 3.

With all due respect to johnmeyer - the 1 and 2 approach to this problem are really plagued with gotchas.Absolutely true, and I said exactly that. I don't know why it is necessary to say it again. The reason I offered those two approaches is that we don't yet really know exactly what the OP is trying to do, and some of these simpler approaches -- even with their "gotchas" -- may suffice, and they require far less work, time, and disk space, compared to some of the other ideas already offered.

There is one additional way to go, and that is to script the process. I have most of the code fragments, but I don't know if I'm really up for doing it. All that would be required is to use the active region selection as the guide, and then split all events on those two boundaries. The script would then delete everything before and after that selection. The tough part, because of how the internals for Vegas scripting work, would be to move all the events within that region selection to the beginning of the timeline. It is a PIA (from a programming perspective) to ripple everything, but trivial to do from the timeline, outside the script. If it were for my own use, or for a free script, I'd probably punt and just tell the person first run the script, and then double-click in the space to the left of the original selection region (which would now be empty). That action creates a new region. Enable ripple, with the bottom selection where everything is moved, and then press the Del key. This will move everything to the beginning of the timeline and would only take a few seconds to do.

Perhaps one of the commercial scripts can already do this.

One of the big problems is Volume Envelopes, sigh.
It's OK for me, I know to watch out for them.


Bob.

Vegasaur has "Create Nested Project" commands using selected tracks or events.
If you need to save a time selection - deselect all events, make a time selection and press S (this will split all events on all tracks).

Loads of useful ideas to try. Thanks!