Compositing Layers on a Single Projector while maintaining Transparency

  • Hey all. Josh Gelb from TiQ here. This is one that's been bugging me for the past year. Maybe it's a simple solution... maybe this is something that really just applies to what I've been doing...

    I'm looking for a way to transparently layer/composite two objects onto a single projector actor (one of which is usually a live feed video in watcher) so that when I move the projector across its various axes the two objects move in sync and the background remains transparent. From what I can tell this is possible with a shape in the foreground (just incorporate the shape into the chain) — but what if I wanted that shape in the background of this layered composite. What if I wanted an image or another movie? The "multimix" function seems to only work additively not transparently. The "video mixer" forces an opacity compromise. And while "effect mixers" work in theory, they force a background opaqueness. My workaround is usually to crop this opaque background, but what if I didn't want a rectangular crop?  No luck so far with user actors, but I'm less familiar with the possibilities of this function. 

    What am I missing here? I'm exhausted by continually doubling my programing to move two objects exactly the same way.

    Love the program. Living the program. 


  • @joshuawg Looks like a basic crop actor works here, if anyone else is hitting the same problem. But only works with a rectangular foreground. The background can be any shape. Any plans for irregular cropping? 

  • Tech Staff

    @joshuawg said:

    Any plans for irregular cropping? 

     I'd use Shapes actor with a full white shape > Projector actor > izzymap to make the irregular shape > send to virtual stage > Get Stage Image actor > Alpha Mask to turn the irregular white shape into an alpha mask that can be any shape you want

  • @joshuawg If I understand correctly you could try the 'Matte' and 'Matte++' actors for layering two video channels that can include transparency.

    For complicated shapes that need cropping or masking I tend to use the IssyMap function in a projector routing to a virtual stage and a 'Get Stage Image' to bring the virtual stage back into the patch.

    Another trick is to use the 'Alpha Mask' actor to create custom masks. Although they only have a foreground and background you can obviously layer them up to keep adding more sources over the top.

  • Tech Staff

    @kathmandale said:

    'Matte' and 'Matte++' actors

     I second using these actors. They are real compositing power houses.