Compositing causes ENTIRE project to render?

johnmeyer wrote on 8/29/2004, 4:40 PM
I screwed something up that required me to apply a five-frame patch every ten seconds of video. I wrote a script to automate the process and ended up with about five hundred patches in a one hour video. The patch was just a simple small rectangualr cutout mask that let a duplicate of the video, offset by five frames, show through the mask. The video was cut into five-frame events at each patch location. There was no video on the parent track other than at the five frame patch locations.

When I go to render the video, Vegas 5.0b renders everything, and as a result takes a long, long time to render.

Question: Am I doing something wrong?

The five-frame masks are on their own track, and I tried moving the five hundred five-frame snippets of video onto their own track so that these two tracks are the only ones being composited. It would seem that Vegas should walk down the timeline and look from top to bottom and then notice when there is absolutely nothing to do for 95% of the frames, and simply copy those frames rather than re-render. Certainly, as we all know, it does exactly this when there is no child/parent relationship.

Hopefully I am just being stupid and there is an easy fix for this.


Grazie wrote on 8/29/2004, 10:39 PM
Mute the tracks you don't need?Even if there isn't anything in the Loop. Heard/read something similar to this the other day. I think it had to do with the "other" track/s exsisting?

farss wrote on 8/30/2004, 2:07 AM
Known problem I believe.
Seem to recall SPOT mentioning it at the VASST training.

PeterWright wrote on 8/30/2004, 4:38 AM
Yes, I found this in another recent thread - I was wondering why straight DV was being rendered, then found that if there are Parent/Child tracks, everything gets rendered -selective render was not selecting.
If I muted the P/C tracks, it went back to normal.

Patch soon, I hope.
johnmeyer wrote on 8/30/2004, 8:58 AM
Thanks for the responses. It confirms what I thought I'd read in the past few months. I submitted a bug report to Sony because I believe this should be classified as a bug. After all, without the parent child relationship, Vegas is quite intelligent about whether it needs to render or not, and will speed through a cuts-only project in seconds (especially if you render to a separate physical disk).
Grazie wrote on 8/30/2004, 9:10 AM
. .which, JM, leads me "back" to what I was chatting about 1 week ago.

IF you've got any empty track that a rendered amount sits above or below, the render process will still "render" the empty space or whatever it does, even though the portion of the rendered track/s are .. er . . ignored. This was my point about VideoWave's SmartRender. It - VW - WOULD ignore that which was rendered and get on with the unrendered bit. Yes, may not be exactly the same, but yes, a bit of tidying-up may be in order? Yes? After all, us veg heads KNOW that Vegas IS hardware agnostic. Yes? We don't want/need RT cards .. right?

We just like muscular MoBos with slippery RAM . . .ooo what an image!

... er .. Grazie ...
johnmeyer wrote on 9/3/2004, 9:12 AM
UPDATE: In working to re-create this for Sony tech support, I found an additional piece of information: The composite mode for the parent track must be set to something other than the default (which is "Source Alpha"). In my case, I had it set to "Cut". If I set it back to "Source Alpha," then only the portions that need rendering are actually rendered (which is what Vegas should be doing, and what it normally does). Thus the bug relates to having a composite mode other than Source Alpha.