I have also noticed a huge quality hit when using a video background i PI. I noticed this a long time ago though.

I always just render via TGA sequence with transparent background, then take that sequence into Vegas.

You can use a "dummy clip" to position your elements correctly in PI, if need be, just don't render that video background with it.

Kind of cumbersome, but it works.

You reallly should be outputting as an image sequence anyway due to the alpha properties.

Also, make sure that you select the correct alpha type. Vegas can accept both straight aplhpa and premultiplied.

Cunhambebe - Maybe I'm getting your question wrong but you don't need a script to play image sequences in Vegas. Just choose File/Open then navigate to the folder with the sequential TGA's. Click the first image and check the box that says "Open still image sequence". Click open, name the "tape" in the window that appears and voila, the images becomes an event in the media pool and behaves lika a normal video event on the timeline.

Best/Tommy

I did the "dino hunters" video over at Kelly Chien's website...
I used Particle Illusion SE (a free version that came with a magazine). That video has 6 particle layers (smoke, fire, lava, tracer bullets, explosion, ray gun) that were created separately in PI SE. Each layer was exported as a tga sequence with "save alpha" enabled. For example, one layer was just the lava flow, surrounded by a transparent background. Each layer had a different particle effect in a transparent background, and the layers were stacked on top of each other in the appropriate order in Vegas.

There is a slight quirk to getting PI SE to export the sequence as a tga sequence of files (don't know about the latest version). To save a tga sequence from PI SE, click on the red record button, then the "save as" screen comes up. The list of available formats doesn't show *.tga as one the options (that's the quirk). But if you type in, e.g., "blob.tga" as the file name and hit save, then another screen pops up where you can specify the frame range you want to render and also "save alpha". Another quirk is that the entire frame has to be visible in the workspace if you want the full frame be exported, otherwise, you'll get unwanted cropped frames.
To get the whole batch of separate but sequentially numbered .tga files into Vegas, go to File>Import media, browse to the folder with the .tga files, and select the first one. Vegas will realize there is a whole sequence of them in the folder, so just check the "import as sequence" box (or something like that). Another screen pops up where you can specify the alpha channel as premultiplied. Bingo, you then have one file for the whole sequence in Vegas' media pool. It'll have that checkered background showing that it's transparent.

BTW, in PI SE, you can place a still image in the workspace background for reference, just make sure the background image is hidden (leaving a black background in the workspace) before you save the *.tga sequence, otherwise it will appear in the exported tga files

I hope this is clear and helpful.

Dan

Thanks to all who took time to respond. In fact placing an AVi file as a background for Particle Illusion seems not to work very well becasuse there's a loss of quality. I've just opened a whole bunch of TGA files with Vegas, selecting all of them instead of the first one. Let's keep trying (Still don't know how to adjust pan/crop and length for each one).
Very special thanks, merci beaucoup, to danieljoelle. I'll try to render in PI with an alpha background.
You know, one thing is certain: it may be easier to set those particles around with PI than Combustion, but rendering with Combustion is much, much easier and there's no loss of quality AT ALL.
Thanks to alll. Le'ts see if I can do it. I'll post some more messages later this evening. ;)

Thanks guys. You've got that right: no need for scripts....sorry....I am a newbie. I did it. It was just a matter to ajust pan and crop. This pan and cro thing make me suffer all the time. Sometimes you have to adjust match output aspect along with Maintain Aspect Ratio. This time, the AVI I had used for the background in PI came from Combustion which uses a misterious codec as "default". I had only to choose "no" for both maintain aspect ratio and stretch to fill frame. Still don't know why we have to adjust pan and crop all the time (but I suspect - because of sizes and codecs, ins't it? loll).
Now, I still don't know how to choose among othe options for alpha when rendering with Particle Illusion. There's a screeen that says:
-Save alpha;
-Remove black bg from RGB channels;
-Create non-intense alpha.

Simple question. Which one do I have to choose?

Then as soon as you open Vegas there are some options too for the alpha channel. Let's see them:
-Undefined
-None;
-Straight (unmatted);
-Premultiplied
-Premultiplied (dirty)...

So please, what do I choose?

Thanks to all for this new lesson. Thanks to danieljoelle, but I disagree with you. I guess you don't need to render each effect for each particle. Can I render all of them is just one file?
Thanks again ;)

Make the AVI uncompressed in Vegas before taking the video over to PI. The quality will be much better in the final PI exported AVI.

Cunhambebe,

No disagreement here. You can use an avi file for the background and render everything together. I was talking about when you need a particle effect to be sandwiched between two other video tracks, in which case you couldn't render the background at the same time because placing it on the Vegas timeline would obscure other layers...make sense?

Always choose "save alpha" if you're render a sequence that has any transparency in it. I rarely choose "remove black", but it depends on the particle effect your using (if you used it for a smoke-like effect, e.g., you would get weird white halo-effect around the particle effect.

See my post above about choosing "premultiplied" when importing into Vegas.

I don't know what "non-intense" alpha is, sorry.

You're almost there...!

Dan

Thanks for taking time to respond danieljoelle (hey are u from Canada? ;)
You wrote: ..." I was talking about when you need a particle effect to be sandwiched between two other video tracks, in which case you couldn't render the background at the same time because placing it on the Vegas timeline would obscure other layers...make sense?"
-Sure, I've never thought about this possibility, thanks for the great idea!

"See my post above about choosing "premultiplied when importing into Vegas."

- I've already made a tutorial out of it. Thanks. Anyway, I've rendered a file with Particle Illusion with an AVI background. Now it seems I've learned how to do it, even rendering as .TGA. Still don't know how to render with an alpha background, though - the final result was weird. Removing "black" make things even more strange; the particles look totally different and rather artificial.

Thanks for your help and congratulations for the excellent video "dino hunters"... ;)

No, not from the Great White North...I'm FROM Arizona, but live in the Chicago area (don't ask...)

Thanks for the compliments on Dino Hunters! It was fun to make.

In case your interested, here's a link to another video I did with my boys in which I also used Particle Illusion:

Rescue Sam

Dan