Question about Pre-render & Lost Transitions

MohammeD T wrote on 11/29/2005, 3:10 PM

Hi alll , some questions i couldnt figure out ..

1- all the transitions i make dissapear after i re-open my project , why does this happen?

2- when do i Pre-render? i read in the help index that i should selectivly prerender some parts of the Video , but why? is there any rule here as to when one should prerender?

3- i have alot of FX in a 1:30 min project and even my Dual core system is down to its knees , should i Render some parts i am done with as AVI? for example i downloaded the 4 split screens from VASST , and droped the Videos , did the edits and so , but i want to combine those as a Video and drop them back to the main Project , it says Video for windows(.avi) <-- is this what i need to render to?

thanks guys

Comments

johnmeyer wrote on 11/29/2005, 4:12 PM
1- all the transitions i make dissapear after i re-open my project , why does this happen?

That shouldn't happen. Are you saying that the events which overlap on the timeline (which is how a transition is created) are no longer overlapped? Or, have you applied some transition other than a cross-fade, and that transition is no longer there?

2- when do i Pre-render?

You don't ever need to pre-render. It is simply done for getting smoother preview. If you have a really difficult transition, or if you have a section of video that has lots of fX and compositing, then Vegas cannot create the video fast enough to display 30 frames per second. If you need to see the video at full frame rate, then you can pre-render. In addition to pre-rendering (which does take some time), there are other tricks for getting real-time or close to real time preview, including using a lower resolution in the preview window; temporarily using a lower project resolution (although you have to remember to set it back to full resolution); or using "RAM preview" which is a special type of pre-render that only renders at screen resolution and therefore happens much faster.

MohammeD T wrote on 11/29/2005, 4:19 PM
jhon , Thanks for your time , the overlap is there , transitions are gone , i am still looking in the prefences , it might be a checked box or so , its strange.

ok , so Pre-rendering only affects the Video preview window for smoother play back , great.

i read here and on the ultimate S plugin that some Film look FX need to be rendered , thats why i thought its somthing i should do every now and then ..
Chienworks wrote on 11/29/2005, 4:45 PM
Everything that isn't strait unaffected DV footage needs to be rendered eventually. That's why you use the Render As command to make your output file.

There are two kinds of prerendering: dynamic prerender (Shift B, often called RAM preview) and selectively prerender (Shift M). They are used for slightly different purposes. Dynamic prerender quickly renders short sections to RAM so that you can preview the finished version quickly and smoothly in real-time. These are purely an editing tool to help you decide if you've got the right effect/transition/composition, etc. They disappear almost as soon as you make any change to the timeline, or if you prerender something else and both prerenders won't fit in RAM.

The selective prerenders are stored as files on your hard drive. While they also allow smooth real-time playback, the main purpose of these is to, well ... pre-render sections that you know are finished and won't be edited anymore. This way when you do the final render these sections are already done and can be included in the output very quickly. Of course, making any changes to a pre-rendered section makes that pre-rendered file invalid and that section must be rendered again. If you use these well you can render your project in bits as you go along and the final render at the end should be very fast. On the other hand, Vegas is very persnickety about these files and will use almost any excuse to decide they're invalid and drop them, so often you end up needing to render large portions anyway.

In either case, you never need to pre-render at all. Each type of prerender can be useful for various situations and it's good to experiment with them to see when they come in handy.

And on your other question, i can't think of any reason other than a serious malfunction for your transitions to disappear. Something's definately wrong.
MohammeD T wrote on 11/29/2005, 5:02 PM
thanks for the detailed info and replay chienworks ..

i found why i lost the Transitions ... and the fades too , but not overlaps.

this is a mixed 4:3 and 16:9 project , and i decided after all to switch the 4:3 clips to widescreen using Ultimate S , so this deleted all Tranistions and fades i did , why? i dont know. i just imported some pics and added transitions then i converted all media to widescreen and there gone.

i should have done the conversion before doing anything else , but its not an issue at all , i just wanted to know why so this doesnt happen again ..
johnmeyer wrote on 11/30/2005, 12:21 AM
way when you do the final render these sections are already done and can be included in the output very quickly.

Except that if you look at Vegas cross-eyed, it seems to "lose" these pre-renders and just does the whole darn render again. The RAM preview is the way to go for speeding things up. It is too bad, however, that it has to rely on RAM. I think the main reason it is so fast is not because it is rendering to RAM, but instead because it renders at screen resolution (I think) rather than project resolution.
Grazie wrote on 11/30/2005, 12:40 AM
Hold that thought, John!

How about using a Nested Proxy as a Previewing option? Nested Timelines make a proxy file. Does/has anybody expressly used this method to Preview a section?

Grazie
Chienworks wrote on 11/30/2005, 3:50 AM
The proxy file is audio only.
Grazie wrote on 11/30/2005, 3:59 AM
I mean the the file nesting file? What is it called? The *.veg.sfap0 . .. thingie? ... The one that gets created when I drop a Veg into a Veg? That file .. isn't that also called a proxy file? No?

Grazie
Grazie wrote on 11/30/2005, 4:20 AM
I am just totally BAD!

Kelly has put me right .. . the Nested Veggies are only proxy audio . . . the video side is still needing to be "seen" in real time by previewing. Where were my brains over this?

Scratch my idea above .. . total nonsense!

Thanks Kelly .. .

Grazie

:-(