Slow down, then reverse

sqblz wrote on 10/28/2002, 7:29 AM
So far I have not been fully successful with this, so maybe someone will bring in new ideas.

I have that movie of my 3-year old son (19 now!) running to and jumping into the swimming pool. The movement is a gracious one, so I would like to do a small trick with it.
To simplify, imagine that this is the full sequence of frames in the full clip:

ABCDEFGHIJKLMNOPQRSTUVWXYZ (full scene is much bigger of course, around 10 seconds).

"W" is the frame were the kid is entering the water. I wanted to slow down the scene from 100% in frame "M" (jump beguins) down until 0% on frame "W". Then, I would reverse velocity, "accelerating" from 0% in frame "W" until -100% in frame "M" again.
Furthermore I want to eliminate frames A to F.

Confused ? Here goes:
A to F - eliminated
F - starts to run - velocity 100%
M - starts to jump - velocity 100%, decreasing until 0% (smooth).
W - touch water - velocity is now 0%, reversing starts
M - after "backjumping" from water, touches ground again. Velocity is -100%.
Backwards continue and Fade Out begins until scene disappears around frame K.

My problem is that I am unable to fix the boundaries of my video, because when I move the beguinning of the scene (to frame F) and apply the velocity envelope, I am unable to fix the end. The conjugation of trimmimg and reversing gets unmanageable.

Try it for yourself and you'll see what I mean.

Splitting doesn't solve the problem, because I am using non-linear velocity change and because my starting frame ("F") does not coincide with my ending frame ("K").

Truly a simple idea but much field for experimenting here. Any hints ???

Comments

TorS wrote on 10/28/2002, 8:48 AM
Remove A-F
Add a velocity point at M
Drag the scene out about as long as you think it will finally be.
Create a point near the end and make it -100%. See how it works.
You may have to drag the scene out more or less, but remember to drag the final point along, too.
I've only discovered this hit and miss method, but it works.

Tor
Tyler.Durden wrote on 10/28/2002, 9:31 AM
Hi all,

You might try splitting the clip first. (You should set TL to display frame numbers as TC in prefs.)

When you split at the reverse-point, you can note the TC number of the frame you need.

Do your velocity envelope on the first segment, and drag the end of the clip to the TC point you noted. It will be the frame prior to the first frame of the next segment.

You can then do the reverse velocity on the next segment... remember to make the event long enough to go backwards your desired length.

HTH, MPH

FadeToBlack wrote on 10/28/2002, 12:35 PM
jdozz wrote on 10/28/2002, 2:24 PM
I've found that rendering sections and pulling them together in another project seems to work for me.
sqblz wrote on 10/29/2002, 7:13 AM
Thank you all, I've got some good ideas here, like handling the forward and reverse parts separately, and joining them at the inverting frame.

To all Tutorial Authors: I LOVE YOU. I collect all the Tutorials I know in my disk, for frequent referral.
sqblz wrote on 12/5/2002, 11:05 AM
Gals & Guys,

I am bringing this thread up front again, not because the suggestions given here are useless, but because I plainly fail to succeed.

For me trying to manipulate a clip with a velocity envelope is like pushing a boiled spaghetti. Literally.

I will explain. Please reproduce this:

Lay down a clip in one video track. Add a velocity envelope. Add 1 point at the end. Give to this point a velocity of 10%. Stretch the right end until the clip ends.
Now, decide that you don't like the first 1-second of this clip: drag the left end 1-sec to the right. Or, if you wish, split the clip at that point.
SEE ? what you get is that the starting of your clip moves along when you drag. The clip is starting exactly at the same frame than before, but some part of the clip disappeared from the right ...

Now, drag the left end of the clip to *left*. Go beyond the beginning of the clip and keep on dragging (you get the small triangle indent, marking the beginning of the clip). If you drag enough, you eventually come to the point where you wanted your clip to start (1-sec after clip beginning). OK, stop there. Now, go to the right edge and drag left until you reach the small triangle.
Now your clip starts where you wanted and ends where you wanted. But the envelope is out of place !!! And if you replace it the clip will tangle and stretch and move again, like the aforementioned spaghetti ...

See what I mean ? Or am I not seeing something ???

I am absolutely sure that there must be MY MISTAKE. This thing couldn't exist without anybody noticing it. But how ?!?!?
philfort wrote on 12/5/2002, 11:22 AM
I can't repro the first thing you said ("what you get is that the starting of your clip moves along when you drag"). For me, it cuts video off the front of the clip. It does also change the end of the clip, because the envelope "squishes", instead of being "cut". Maybe that's what you mean.

I'll agree that the velocity envelope is a bit of a pain to work with. There should be a way to have such that the beginning and ending of your clip remain fixed (with respect to which frame they reference in the source media), but that as you adjust the envelope, the end of the clip (in the timeline) moves back and forth. Of course, as you slide the envelope through 0% into the negative zone, it will briefly extended to infinity, so I guess there are some issues on how they'd have to deal with that.

When working with velocity envelopes, I usually just ignore the end of the clip for the moment, just making it big enough such that I can do my work with the envelope, then at the end, I adjust it to end where I want to. It's really not that bad, you should be able to achieve what you want... just make sure you don't intend to change your starting point, so "edit" before you add the envelope. Then just go along the the timeline making adjustments to the envelope, extending the end of the clip as necessary. Sliding the beginning of the clip around is just asking for trouble :-)

BillyBoy wrote on 12/5/2002, 12:11 PM
I agree with the previous poster. Before you try to do any time stretching, complete your editing.

Try s t r e c h i n g by holding down the end of a event while you press down the CTRL key. This should add a ziz zag line through the event. If you drag left, you speed up, drag right, you get slow motion. Once you are happy with the speed don't forget to right click, switches, resample. You can use the envelope method as well.

What you seem to be doing is dragging the event boundry without holding down the CTRL key, which only moves the pointer indicating the current end of file... not what you want.

You'll have the best success if you break into very small events applying whatever effect you want to each. If still not happy, select the entire range, render, remove the original source files from the timeline and replace with the file you just rendered. In other words, render ABCDEFG... as a group. Then if necessary once rendered rework it again which should allow you to slow it down more. If you do this I drag the events out in the first pass, then apply the envelope to the rendered section.

Tyler.Durden wrote on 12/5/2002, 5:21 PM
Hi sqblz,

Here's a thought...

If you have a clip that you want to keep the envelope relationship to the media, and you want to trim the ends, you might try placing it on another track and use the overlap of the adjacent clips to determine the transition-point.

Another consideration is to split the clip at the point you want to start the event, then delete the first segment. The remainder of the VE relationships should stay the same. You can then drag the prior event back to the VE clip, or move the whole event up in time.

More steps than a simple drag-trim, but VEs are quite complex events made easy by VV.


HTH, MPH

Tips:
http://www.martyhedler.com/homepage/Vegas_Tutorials.html

sqblz wrote on 12/6/2002, 9:02 AM
Thks, Marty, the overlap idea is one that I hadn't tried before.
(on a sidenote, IMPORTANT QUESTION TO SoFo: why can't we have a "transparency envelope", like we have a "velocity" and a "volume" envelopes ? why have we only the means of changing the transparency identically throughout the whole clip ?)

As for the other one
" to split the clip at the point you want to start the event, then delete the first segment. The remainder of the VE relationships should stay the same. You can then drag the prior event back to the VE clip, or move the whole event up in time."

please try it and correct me if I'm wrong, but I think that it doesn't work. Unless, of course, if I cut the clip *physically* in an external program. If I only split, the startpoint of the enveloped clip will be *again* at the beginning of the splitted clip, and the endingpart will be reduced accordingly. This must be because the split is just a "virtual" shortening of the clip, that remains physically unchanged ...

My best bet so far has been: cut, re-render, envelope, re-render, cut, re-render, reverse, re-render, .... practical, isn't it ???
Tyler.Durden wrote on 12/6/2002, 10:12 AM
Hi SQ,

My understanding is Vegs 3.0 offers opacity envelopes... I have used them a bit.

Try Insert>Video envelopes>Track composite level. Keep in mind track-level effects may alter render times for entire program (unless you render to new track).


As for splitting a VE event. You are completely correct, and I was mistaken about the heads of events. My bad, but here's a thought:

When you split a VE event near the head, the tail of the new first portion will indicate the proper frame number (if you disply in the TL, using prefs) where you can start the second portion. I used the slip feature (Alt-drag) to pull the second portion's media to the correct starting frame and VE relationships downstream should fall in properly.


HTH, MPH

Tips:
http://www.martyhedler.com/homepage/Vegas_Tutorials.html

jetdv wrote on 12/6/2002, 10:13 AM
You DO have a transparency envelope. It's called a "composite" envelope.
sqblz wrote on 12/10/2002, 8:26 AM
Nice tip, MartyH. Thanks.

Nice hint, jetdv. Indeed, I am not keen at using the composite facility. Surely my mistake.

So far, I have been limited by the idea that I create 2 composited video tracks because I may wish to create a 5-sec effect, and then I will have to live with those 2 tracks for the rest of my 1-hour project, without re-using them ...
Because the compositing works at track level and not for one region only. Right ?

Or else, I will use small VEG subprojects only for intermediate compositing and reintegration in the main job. Right ?

What is your practice ?