Compositing particleIllusion SE

vitalforce wrote on 5/11/2006, 3:29 PM
I am trying to create an FX clip at the beginning of a 'film' (24p DV), to make a group of small explosions move from top to bottom (simulating a bombardier's view of distant bombs hitting the ground as he flies past them). I put PI's uncompressed avi file--a cluster of sequential explosions--on the Vegas 6 timeline (no problem) but when I have Vegas move the frame top to bottom, although the clip background is black and so is the Vegas background, the outline of the top edge of the frame is visible as it moves down across the screen.

I have the PI avi file on the top track, composited as a source alpha over the "night" track of the picture. Is there another setting for the top track, for instance, that would avoid the faint white line of the vertically moving frame?

Comments

DJPadre wrote on 5/11/2006, 6:17 PM
I am trying to create an FX clip at the beginning of a 'film' (24p DV), to make a group of small explosions move from top to bottom (simulating a bombardier's view of distant bombs hitting the ground as he flies past them).

((OK))

I put PI's uncompressed avi file--a cluster of sequential explosions--on the Vegas 6 timeline (no problem) but when I have Vegas move the frame top to bottom, although the clip background is black and so is the Vegas background, the outline of the top edge of the frame is visible as it moves down across the screen.

((Do you have transperancy in Vegas turn ed on (ie, right click, go to properties, and turn transparency to Premultiplied??))

I have the PI avi file on the top track, composited as a source alpha over the "night" track of the picture.
((as in Parent Child? U dont need to do this...))

Is there another setting for the top track, for instance, that would avoid the faint white line of the vertically moving frame?

((That faint white line isnt a line itself, its a remnant of your composition mode..

Inport the clip into PI, and once you allocated the start point of your explosion, can actually record your motion on screen.. ie, move the mouse around and those actions are recorded as keys. From there u can smooth it out..

Im having trouble understanding what youre trying to do???

Do u have a scene where there are multiple explosions?? Or do u have one explosion which youre wanting to evolve/track over an area??
I understand your trying to achieve a specific top down view of something, and to do this, i would really only recommend you composit this in AE (if u have it) or PI itself Reason i say this is because you want to lock the lower geographical layer (ie your image of the city per se) and then lock in your effects.. however, if you just throw on a layer of explosions over your geog, then the perspective of those explosions will be very 2d and seem to be cardboard cutouts.. IF however you track the scenes individual explosions to the motin of the scene itself, then render out of PI, you wont even need to lock the 2 tracks, as youve already locked the explosions to their own point.. also with this motion, it will give a more authentic feel to it as each explosion is different and reacts differently as opposed to a blanket panning down of your top layer...
vitalforce wrote on 5/11/2006, 7:20 PM
Wow. You're smart.

I'm going to start with the first few ideas, beginning with avoiding the parent-child mode (and thanks). To answer your question, this is the opening graphic of a movie where there is only a suggestion of a night bombing campaign. Black screen, faint stringy clouds begin to pass by (from top to bottom), sound of an angelic choir fades into the rumble of a bomber group, then the whistle of falling bombs, and then one jagged row of explosions in the night below, followed a second later by another jagged row at a different angle. I follow the semi-random distribution and sequence of WWII daylight bombing footage to create the effect, which fades into a woman walking in snow, without snow shoes, carrying a suitcase...then the story begins.
vitalforce wrote on 5/11/2006, 7:42 PM
Got it. First, thanks for the many tips, I have some interesting stuff to experiment and learn with so I appreciate your time taken to deal with this.

What I tried in the process of futzing around, was to go to the pan-crop window and put a mask along the four edges of the frame, feathered inward by about 2.4. No more line.
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