Vegas 5 - multiply composites and glow effects

cipher wrote on 5/14/2004, 1:27 AM
just downloaded the trial version of vegas 5 - its pretty cool.

a couple of odd things i noticed: i was doing a 2 layer composite, with the top layer set to multiply, and when adjusting the layer's transparency slider the layer faded to black...??? shouldn't the layer beneath it show through like other apps...? i'm very new to Vegas so it could be something quite simple i'm missing.

also is there a way to do alpha glows yet? eg. when comping one layer onto another normally you'd have the area of the top layer's glow defined by its alpha channel. this is a very common compositing feature i hope there's another way to do it...

any tips much apprec.

Comments

Spot|DSE wrote on 5/14/2004, 6:50 AM
You don't need to set the upper layer to multiply, just leave it at alpha.
also, you can parent the upper track, set the mode to multiply, and change the opacity on the parent Track Motion, and set the glow there, too.
the tools are there, just different than what you might be used to in Combustion or AE.
cipher wrote on 5/14/2004, 4:11 PM
hi - thanks for your reply - i tried what u sugested but with a parent/child relationship the top layer still fades to black. and in that scenario with it set to multiply everything is always black. :(
i can't see any transparency controls in the parent's track motion...

i should point out that the glow thing is a seperate issue. not concerned about that. i just need to be able to fade out upper layers that are set to multiply, not alpha. (this is for compositing shadows rendered from a 3D package).

Spot|DSE wrote on 5/14/2004, 4:37 PM
Vegas will auto recognize anything with an alpha in it, if it's not recognizing it, then right click the 32bit file, and choose Properties/Media/Alpha channel.
If it's 3D, you'll probably want to use the dirty premult.
cipher wrote on 5/14/2004, 7:09 PM
the images don't have alpha - (although the same result happens with an alpha channel).

there are no areas of transparency in the image[s], its not an alpha issue - its the fact that the track fade doesn't actually fade out the track when the top layer is set to multiply.
farss wrote on 5/14/2004, 7:34 PM
I think you'll find that the track fade is working correctly, it's fadin to black which is 0 and multiply anything by 0 and the answer is 0 i.e. black. If you have to use mulitply try fading to white (1) might fix your problem.
cipher wrote on 5/14/2004, 9:05 PM
i tried altering the fade colour - same result but i know what's going on now - if its working 'correctly' then Sonic/Vegas are clueless and have missed the point about how layering is used for basic compositing.

in every other application on the planet, (you can test this in combustion, AE, premiere or even photoshop), the layer opacity controls the amount of "effect" that layer has in the resulting composite, eg, how much it contributes towards the resulting image, regardless of what overlay method is used.

say the top image is set to multiply - only the information in that image should always be used for the multiply result, but what Vegas is doing as you fade out that layer is its introducing image information of zero, which like you say will give any multiply a result of zero, and won't let the background image show through. in a way its not even a real multiply 'cause they're 'adding the black' before the multiply.

i'd be curious to hear from the developers on this issue...


farss wrote on 5/15/2004, 1:31 AM
Only a stab in the dark here but there are now three types of composite envelopes. If you're using 'Track Fade to Color' then I'd suggest it's doing precisely what it says it should do.
If you're using 'Track Composite Level' then I'd expect it to do what you want it to although I cannot quite figure out the 'arthmetic' of how the created alpha data would enter into things.

But anyway there should be a fairly simple but perhaps inelegant workaround. Place a duplicate of the lower track on the top. While you have your composite happening using a composite envelope set it to 0%. When you want to fade out the effect bring the level up on the top track.

I've always felt that the way some of the layering worked wasn't quite right but I've never tried it in another app. so I'd figured myabe it was just me. What was happening seemed logical but not intuitive.

Cheesehole wrote on 5/16/2004, 8:24 AM
"i tried altering the fade colour - same result but i know what's going on now - if its working 'correctly' then Sonic/Vegas are clueless and have missed the point about how layering is used for basic compositing."

I'm embarrassed to say I hadn't noticed this before. It does work differently than other compositing software. Setting the track compositing level to 0% should give the same result as "MUTE", but it doesn't. This seems inconsistent. There needs to be another slider, or the MUTE envelope needs to be a normal envelope and not a ON/OFF thing. I too would like to hear Sony's side of the story - perhaps we are missing something.

But the simple work around is to do just as Bob suggested. Set the "fade to" color to white and use the "Fade to Color" envelope to fade the track in and out. I just tested it and it works. Let me know if you want the .VEG

- Ben
Cheesehole wrote on 5/17/2004, 7:58 PM
Does it seem inconsistent to anyone else that a track level of 0% is not the same thing as "Mute"? There's got to be a way to fade out a track so it becomes invisible to the composition stack!?