Placing .AVI w / alpha on track above vs below

LReavis wrote on 3/11/2010, 9:24 PM
I prepared a composite, starting with a .PNG with alpha of a spaceship on the top track. If I put an .AVI with alpha of flames on the track below, I can see it through the alpha of the .PNG and see the flames, just as expected.

However, I wanted to put the flames on the track above so that I could position them directly onto the spacecraft's thrusters, and SURPISE! Placing the .AVI on the track above the .PNG resulted in the .AVI becoming invisible - no flames, no nothing - just the track BELOW (spacecraft .PNG) is visible. If I mute that track, then the flames from the .AVI on the track ABOVE become visible.

How is this possible? I thought that the top track always took precedence - how could muting or unmuting the track BELOW affect the track above?

Similarly, if I put a solid color on a new third track (placed as the lowest track), it blanks the .AVI on the track above (the middle track); but the alpha on the top-track .PNG still works, so I can see the solid color through the spacecraft .PNG's alpha channel (the spacecraft also is appropriately visible). But why can't I see the .AVI sandwiched between the two other two tracks?

I created the .AVI flames from Particle Illusion and rendered to Logarith RGBa (alpha), like always. I did it twice, making sure that I did it the way I'd always done it. Bringing the Logarith RGBa into Vegas, I went to Properties>media>alpha and chose Premultiplied. I'm almost certain that's how I'd always done it, but I have never before seen this strange behavior where changing the track below affected tracks above.

It should be noted that the .AVI thumbnail in the Project Media bin just shows a blank checkerboard as if the entire frame is an alpha channel - no flames are shown in the .AVI thumbnail.

I'm using Vegas 8c on Win7-64bit; this is my first Logarith AVI in the 64-bit system. Suggestions?

Comments

Grazie wrote on 3/11/2010, 10:43 PM
LR? Can you do a screen grab of your Timeline including the Track Headers, and make a link to here? Sounds like you have a Track Compo control going on.

Cheers,

Grazie
Grazie wrote on 3/11/2010, 11:20 PM
R U sure you rendered out from Pi correctly? Save Alpha? "Remove black bg from RGB"? - I also get a "gotcha!" by that?

OK- Can you check, in a fresh Vegas instance, that you ARE getting a trannie BG on your rendered out Pi stuff?

I just re-acquainted myself with 32-bit Pi and this works well. I also use Lagarith - marvellous!

Grazie
LReavis wrote on 3/12/2010, 11:43 AM
friend Grazie - thanks for the prompt reponse and suggestions. Here are the screen shots:



The one above is with the solid color track muted, as you can see. The following is with all 3 tracks active:




so sorry - I can't quite understand the intent of the question, "Can you check, in a fresh Vegas instance, that you ARE getting a trannie BG on your rendered out Pi stuff?" - "trannie"?

In any case, yes, I did save alpha and put a checkmark in the box "remove black background . . " - did it twice just to make sure I'd put in all the required checkmarks. It always worked on my 32-bit WinXP.

Incidentally, I'm getting exactly the same behavior in Vegas 9C-32 and 9C-64bit. I'm beginning to think that Logarith is not working right on my system. I checked the codecs installed on my system, and I have Logarith 1.3.20 - which has to be the 32-bit version of Logarith. I have downloaded the 64-bit version, but my 64-bit version is 1.3.19, and there is no such codec installed on my system.

Grazie wrote on 3/12/2010, 12:26 PM
Wow! I can't see anything that would do that?

I have :-

A) T1 PNG with transparent BG

B) T2 a Pi Explosion and transparent BG

C) T3 a Torq solid

I can see you DO have a trannie (transparent) BG (background) to your flames - even though I can't see them on your Timeline, as your Preview is obscuring the position of the rocketflames.avi - no matter.

No, I have NO idea why the torq Event on T3 should blow away your flames. Makes no sense at all. I've just attempted to repro your outcome, but I can't. For me all the 3 items are working as I and you would expect, and I am using Lagarith too.

What version of Vegas are you running?

Grazie

LReavis wrote on 3/13/2010, 4:01 PM
I started with 8c, but get the same behavior in 9c-32 and 9c-64. . . it's really a puzzle, but thanks for trying
Chienworks wrote on 3/14/2010, 6:48 AM
What's disturbing me is that we can't see the rocket flames in the rocket flame clip. It looks like it's entirely transparent. Notice how we see the ship on the checkerboard background. Why aren't the flames displayed too? I'd guess something went wrong in Particle Illusion. You may want to try creating the file again.

The other weird thing is that when you have the solid blue background active it shows up as black in the preview. Why wouldn't it be solid blue?