How to work with vegas on prerenders

winrockpost wrote on 2/20/2005, 11:16 AM

yea the prerender deal is a bit shakey, sometimes i seem to lose them all for some reason like I sneezed,I never figure it out, seldom even use it anymore cept for checking small sections as i go down the timeline. Usually just render to a new track, but would rather have some predictablity (if thats a word) with prerender. Dont know the answer to why the renders are small segments or large.

JL wrote on 2/20/2005, 11:56 AM

As I understand it, prerendering only affects portions of the video selection that need extra processing for preview at full quality and frame rate. Portions that don’t require extra processing are skipped over so depending on the selected section, the process may create multiple prerender files. Also, sections may be further broken into smaller prerender lengths to limit the size of the individual prerender files. Any additional editing after prerendering will invalidate only those prerender files affected by the editing.

JL

rmack350 wrote on 2/20/2005, 2:29 PM

This is an area where prerender is "smart", if you can call it that. If not much prerendering is required then vegas can do it over a long stretch.

Vegas prerender is diferent from most other NLEs. In other NLEs you might render a transition or a title or something. In Vegas terminology you'd be prerendering an event. However, Vegas never, ever prerenders events. It prerenders the timeline. If something changes in that area of the timeline then the prerender is gone.

Rob Mack

fultro wrote on 2/20/2005, 4:13 PM

By "that area of the timeline" I figure you mean between the in and out points of the pre-render. It makes sense to me that you would lose the pre-render if re-editing there.
But from my experience "that area of the timeline" can mean just about anything from half an hour away on the timeline to doing nothing more than going out for a coffee break.
From what I am gathering from this and similiar threads (inc one I started) people have different ideas and experiences about what pre-rendering actually does (And please don't anyone jump in here with the verbatim help file explanation on this one)
I wish someone from Sony would jump in soon and clarify if there is something we are all missing which has driven many of us away from even bothering with the function (if I may speak for others )
From my point of view it wouild be great to have it work consistently because as long as I don't re-edit that part of the timeline i know I could save that much time later on the final render - at least that is what the help files seem to promise.
fultro

tbrucebowers wrote on 2/27/2005, 5:05 PM

Prerender seems to be broken in Vegas 5.0d.

In earlier versions, prerenders would show up as green bars at the top of the timeline, and as long as you didn't mess with anything within one of those green bars it would survive.

In this version, prerenders show up as gray bars at the top of the timeline, and if you change anything, anywhere in the timeline, all prerenders are lost

Anyone at Sony care to comment. Obviously a lot of people are having trouble with this, and it is becuase it is broken, it used to work pretty well.

fultro wrote on 2/27/2005, 5:11 PM

thank-you - I'm not crazy ..
lets keep up the pressure and get this fixed ---- Paleeeze

tbrucebowers wrote on 2/27/2005, 6:27 PM

I'm wondering if it's not broken for everyone. If it was, I think we'd see even more noise about it. Perhaps there is a corrupted config file or something else that is causing it. The first step is for someone from Sony to take a serious look at it. Anybody listening or is it time for a Tech Support call?

filmy wrote on 2/27/2005, 6:45 PM

I might be missing something in this thread but Vegas has never really "kept" the previews. It is someting that has been moaned about for the last few versions. I am not talking about "smart rendering" or "preivews to ram" - I am talking about the temp renders to the hard drive. The green/grey lines showing what is in a temp loaction might have changed - not talking about that.

What has been said is always what seems to happen - do any sort of temp render and if you make an edit anywhere they vanish. And yes, sometimes just going out for a bit and coming back they seem to vanish as well.

This is what I am not sure about here - this is just the way Vegas has worked with these files, it seems to be by design - not a bug. But again, maybe I am missing something in what you are calling a "pre-render". For me when I actually pre render something to be kept I call a "pre-render"...the temp files that Vegas does I don't think of as pre renders in the same sense because they are, by design, temp files. If you want to save these files you need to either "render to a new track" or do a "render as". Now, I can understand that these temp files are being "pre rendered" in antcipation of *being* rendered - however, again, they are still only temp files. If you don't render at that point - as annoying as it may be - these files just go bye-bye. And *that* is the issue that has been discussed over and over again...that Vegas should add this feature or option to keep the temp files. If I make a cut at 30 seconds it should not destroy something at 5 seconds, nor should it wipe out something that is unchanged at 50 minutes either. In that department other NLE's are "smarter" than Vegas. But, I will say it one more time - this is not a bug in Vegas, it seems to be by design that Vegas handles these files that way.

JL wrote on 2/27/2005, 7:18 PM

Under the Tools menu there is ‘Selectively Prerender Video’ (Shift + M) which is I think what most users (and the manual) refer to as prerendering, and which creates temporary prerender files in the location specified under the project Properties. If you want to keep the prerender files you need to check the following:

Options > Preferences > General > ‘Save active prerenders on project close’

JL

tbrucebowers wrote on 2/27/2005, 8:23 PM

Yes,
Tool/Selectively Prerender video - Shift M

Something I've done 500 times a day since I got Vegas, and also something that does not work like it used to. And yes I have "Save active prerendrs on project close"

I used to be able to prerender a section that contained a lot of processing and layering so that it would play at full speed and rez, and then I could change something outside of that region and that prerendered section would remain. It does not now. If I change a video event anywhere in the timeline even if it has nothing to do with the time region or video events that are in the prerendered section, all prerenders are lost and must be redone. I don't know how to make it any more clear. Used to work, doesn't work any more and is basically usless until it get's fixed.

fultro wrote on 2/27/2005, 10:14 PM

Yes, again--- for me too -- Selectively Prerender means
"Tool/Selectively Prerender video - Shift M"

But this problem does go back earlier than 5.0d for me - probably back to v4-- those perenderd files can be dragged back to the timeline to work - but of course - what is the point of that ?
So if you can say that this is all by design not by error than I have to ask - what is the point of having it at all - it is really no better functionally than a ram preview
fultro

tbrucebowers wrote on 2/27/2005, 10:28 PM

This leads me to believe it is some sort of corruption. I started having trouble with it sometime around when I went to 5.0. It took me a while to realize that it was happening because even with the way it was before, if you changed the wrong element you would lose the prerender. That was to be expected, but now if you change anything ANYWHERE in the timeline you lose ALL of the prerenders.
I'm wondering if it could have anything to do with the fact that all my video is on Firewire drives now.
How about you? Did it ever work for you? Are you using Firewire drives?

fultro wrote on 2/27/2005, 10:39 PM

I have worked to ide, scsi and firewire - it matters not with this issue

tbrucebowers wrote on 2/27/2005, 10:41 PM

And it did work for you at some point? It most definitely did for me, but it's gone now. If it did work for you before, can you remember anything changing around the time it stopped working?

fultro wrote on 2/27/2005, 11:44 PM

OK - my memory on this is a little foggy because I was learning so much stuff at the same time about two years ago - and thats when I got into Vegas with v3 I believe.
I certainly remember never being happy with the prerender function, but at the time, being new to NLE, I just chalked it up to something I wasn't doing properly. But since learning other programs with various methods of previewing in the workflow - I have come to realize that this is either not working or that it doesn.t make any sense to me in how it is implemented.
And I cannot remember any specific thing that I did differently that changeds this behaviour

filmy wrote on 2/28/2005, 12:49 AM

I got you. Yes, there is the whole pre-render video part that you mention. I just have never really used it because the first time I did, and then the first time I made an edit after using it, and it all vanished form the "timeline" I stopped dealing with it. But I think there might be a few issues at play - according to the Vegas manual/help file:

Each prerendered section will consist of no more than 300 frames (approximately 40 megabytes). Because selective prerendering creates multiple files, minor editing on the timeline will not invalidate all of your prerendered video—only the sections you modify will need to be rerendered.

Now on paper that makes sense except for me, and others, if you make a cut - as in remove something and the timeline ripples - everything vanishes. In a way you have now changed the entire timeline, so in a sense you have modified the entire project and it is doing exaclty what it says it will do...only the sections you modify will need to be rerendered. In the case I mentioned that would be the entire timeline past where you have removed a shot. So I think issue one is how the timeline is working in relation to the temp files. Does it work cut by cut or based on the entire timeline? For me it seems to work on the entire timeline. I am getting the idea that for some of you it works (or used to work) "correct" in that you could remove a shot at 5 minutes and ripple and still have all the temp renders in tact. It never has worked for me that way, so I am a bit jealous of you all who had ti working that way. That is why I think it is "by design" - because for myself, and others who have mentioned it, it seems that while the files may be "saved" they don't actually "save" in relationship to the timeline. If I did a selective pre-render on a scene and than decided to move that scene/shot to another spot on the timeline, unchanged, the temp file doesn't seem to move with it. Maybe this all ties in somehow with the "flash frame" syndrome we talk about.

fultro wrote on 2/28/2005, 1:04 AM

OK - the part about ripple editing screwing up the timeline makes sense if the new edit occurs before the prerendered section on the timeline - but I have this problem even if I prerender a section starting at the beginning of the timeline and leave that part of the timeline alone while I continue adding and editing later on the timeline. The ripple edit effect should not bother earlier prerenders especially if no envelopes are involved on the timeline - or so I would think.....

JL wrote on 2/28/2005, 1:44 AM

I’m not experiencing what you guys are. I can make edits anywhere along the project timeline and only affect the one or two prerender sections in immediate proximity to the edits; all other prerendered sections remain intact. The exception is when making edits with ripple on and set to anything other than ‘Affected Tracks’ only, in which case it does wipe out all prerendered sections.

JL

filmy wrote on 2/28/2005, 8:30 AM

>>>The exception is when making edits with ripple on and set to anything other than ‘Affected Tracks’ only, in which case it does wipe out all prerendered sections.<<<

Hey - I would have never thought of that - "Affected Tracks only" would keep the temp files. With me, I only work with all tracks turned on. I don't see how one could maintain sync otherwise. I have said it before but why someone would only want to ripple one track is beyond me...and that being so the temp pre-renders are *really* called "temp" for a reason. ;)

tbrucebowers wrote on 3/1/2005, 10:09 AM

Ok, This is mostly for fultro.

I just fixed it at least for now. I just went back and reset my location (File/Properties/Video/Prerendered files folder) for the prerendered files and it is working properly again.

I thought it might be something like this because no one else was having the problem. Try doing that and see if it helps. Even if it has worked in the past in the same location, try changing it, saving and then changing it back. Something was getting corrupted that isn't apparent from the Properties page.

Good luck,