Weird chromakey bug

GregFlowers wrote on 1/6/2004, 1:01 PM
I've recently switched from Premiere 6.5 to Vegas 4.0 and love it! I am having difficulty getting the chromakey to work properly. I am used to using the Primatte Keyer in Commotion but thought I'd try the chromakey in Vegas for a change. I set the green screen footage on track #1 and place the background below it on track #2. I do not set a parent-child relationship. I use the eye-dropper to select the green screen color and it eliminates the green but the background track does not come through, only a solid black background. I can get an excellent looking mask with the slider adjustments but it will not composite the two tracks. On the timeline the green screen is gone with the checkerboard (transparency) showing through indicating it has been keyed out. Effects are not bipassed. Tracks are not soloed. Compositing mode is source alpha (default). I can render the file as an uncompressed .avi and import it back into Commotion and it is perfectly keyed. I have uninstalled and reinstalled Vegas with no effect. Anyone have any thoughts or suggestions? I very well may be overlooking something obvious.

Comments

cyanide149 wrote on 1/6/2004, 1:30 PM
In the chromakey window, do you have "show mask only" unchecked? Is the sync cursor disabled?
GregFlowers wrote on 1/6/2004, 2:02 PM
When I uncheck the "Show Mask Only" box I have the subject against a completely black background, instead of against the desired background located on track #2. I'm not sure about sync cursor enabling/diabling. Would you mind elaborating? A post by a different guy on another forum with a similiar problem uninstalled and reinstalled Vegas and it fixed it. It did not fix my problem though.
AlexB wrote on 1/6/2004, 2:51 PM
In the Preview Window, SplitScreenView pressed with FXBypass? I don't get any checkerboard patterns in the timeline. Did you pull the opacity line of the background video to 0% by mistake in the timeline? Same for Opacity level in Track list?
Have look at the example by taliesin at vegasvideo.de, ignoring the German text and looking at the pictures.
GregFlowers wrote on 1/6/2004, 3:47 PM
I made a mistake when I said I was getting a checkerboard pattern in the timeline. It is just the original greenscreen footage. With split screen enabled with FX bipassed I get green on one half, black on the other half and the subject looks normal. The opacities are set to 100% on both tracks. I can get a green channel key from the mask generator to work but it doesn't produce good results. I feel like I am doing everything correctlybut no composite. Its weird that I can render the .avi as uncompressed and take it directly into Commotion fully keyed, which tells me it is correctly keying out the green, just not letting me composite it in Vegas.
Udi wrote on 1/6/2004, 10:23 PM
It is weird, Try to lower the opacity of the upper track and make sure that the lower track is shown. Also try to mute the upper track ans make sure the lower track is completley shown.

Udi
lynj wrote on 1/6/2004, 11:13 PM
In the FX box there are three adjustments you can make with sliders. Play with them some while looking at the split screen. You will make the black go away. Good luck.

Lyn
taliesin wrote on 1/8/2004, 7:36 PM
On the left side of each track there is a small icon looking like an exclamation mark. Are you sure this one is unchecked everywhere? If it is checked on one track you'll see only that one track.

Marco
taliesin wrote on 1/11/2004, 3:52 AM
Greg, solved the problem?

Marco
dtainer wrote on 3/9/2004, 10:17 AM
I am having the exact same problem as Greg.

I'm using a Flexdrop 5x6, lit evenly, as is the subject following as many good forms of lighting as possible. I get a great key using the stills in photoshop. In Vegas, it appears to key out everything perfectly (it goes to black after using the Chromakey filter plug-in) but it does not composite with the image (or video) in the lower track.

I'm stumped: I've tried everything mentioned previously in this post. If someone has solved it, please let me know.

Thanks,
Dave
dtainer wrote on 3/9/2004, 11:28 AM
One other thing I didn't mention is that I'm using the Panasonic dvx100a using Cine-Like gamma 2 and the 24pa mode. This shouldn't matter, but in case this jogs anyone's memory.
-DT
dtainer wrote on 3/9/2004, 11:52 AM
Guess I'll answer my own question (I should have done what I tell my students to do--don't ask until you've exhaused every other option!):

The problem was in the interplay between the high threshold and the low threshold in the chromakey plug-in. One other thing: I omitted the step of using the eyedropper--that seemed to be introducing another problem. Looking at the Deutsches link above helped me look at this problem in a new way to be able to solve it. Thanks.

My settings:
Chromakey filter w/Green screen preset, then manipulating low threshold to .624, high threshold at .806, with a blur amount of .002 (just a touch cleaned it up beautifully).

This is the best key I've ever done--way better than all the work I used to do in version 3 (I didn't have the photoflex flexdrop then, either)! I think I'll be able to get some rest tonight, now :)
-DT