Blackmagic Forum

[Edit: Solved!]

I tried searching for this, but I couldn't find the solution.

I am trying to apply a Polygon mask within a polygon mask - my shot is a man with his hand on his hip, and I need to see the clean plate for the shot behind him and through his arm. I've got the Polygon mask for his shape (not green screen), but I don't know how to create another mask for the area inside his arm. I have tried using Merge nodes to combine two Polygon masks, but that didn't work, and I tried:

source(background and foreground) --> merge1 <-- polygon1 <--polygon2 || merge1 --> media out

as well as

source --> merge1 with polygon1 --> merge2 with polygon2 --> media out

I hope those make sense - I'm just learning Fusion and I'm actually liking it much better (so far) than After Effects.

How do I use multiple polygon masks on one clip? Thank you!

Just plug one Polygon into the Effect Mask input on the other. You can chain as many as you like that way, and you can combine different kinds of masks together, like Polygons with Bitmap nodes. When you've made the connection, you'll also get a Paint Mode control in the downstream masks that let you determine how they combine together.

A Bitmap has two inputs that you can use to combine two branches of roto together.

Perfect! Thank you! I had to try out the different paint modes, and Invert is the winner! Thank you for the quick response - like I said, I'm still learning, but once I started to wrap my head around how the nodes work together, I think it's actually more flexible than After Effects.


Thank you!

Hi, I am very new to Davinci. I am trying to use multiple (4) polygon nodes each with a garbage matt. One node works fine, two nodes does not work and my keyed area disappears.

Any advice on how to use more than one polygon - for dummies?

Thanks

I'm trying to figure this out also. I'm doing some simple roto in Fusion, trying to use a MultiPoly node to make several roto shapes to mask a foreground image onto the background -- standard stuff.

But only one of the shapes in the MultiPoly seems to be working, even though I haven't changed the settings on either one of the two shapes. The second shape is there and I can view its curve, but it isn't adding anything to the matte though it definitely should be.

Is MultiPoly broken?

Piping masks through each other worked the way it's supposed to, but the MultiPoly is only apparently generating a matte for the first shape.

Check for the; shape animation if you want animated. Paint mode set to appropriate setting for what you want, and that the polyline or B-spline is actually closed. If you want closed spline instead of open one. (SHIFT + O)

Neither of those has anything to do with the MultiPoly node only emitting a matte for one of the polygons in it.

Rakesh Malik wrote:Neither of those has anything to do with the MultiPoly node only emitting a matte for one of the polygons in it.

Better post a node set up and screenshot to clear up what is happening.