Can you use Movie Studio Platinum 12 (not professional) to nest projects - or to make different parts of a movie as separate projects, then import each separate project into a unifying project that acts as a concert of the different parts? If so, how do you import into the unifying project?
No nesting like the Pro version has. You've got a couple options.
1) Copy & paste from one timeline to another. Keep in mind that this only copies event information, not track information. Track settings, envelopes, and markers are not copied.
2) Render sections from one project and bring the rendered file into another project. This preserves all the track settings that copy & paste would lose, but at the price of needing to go back to the original project and re-render and re-import should any changes be needed.
Here's another option. My projects usually consist of several small projects (5 to 10 minutes long) as they are easier to manage than one large one. A recent project consisted of 31 of these smaller projects (for burning to Blu-Ray) and, after rendering, I found that DVD Architect Studio struggled to cope with this number. I'd read on this forum about combining MPEG files using the DOS command copy /b and carried out a little experiment to see if this would work with my .avc files. I divided the total number of the rendered .avc files (some were shot in 1080x1440 and the rest were shot in 1080x1920) and created two large .avc files using the DOS command copy /b *.avc combined.avc. For the audio streams (I render to .wav files) I had to use an audio editor to concatenate them, I couldn't seem to get the copy command to work on these.
I then brought these into DVDAS and authored my Blu-Ray project.
I have just completed testing it and everything is good.
This will be my workflow for any new, large projects I have.
Remember though not to combine video files with different resolutions.