Open 3d Shape as a mask?

I have a memory of one of Grants videos showing how to use an open 3dShape as a soft edged mask within action, then using it to apply a lighting effect along the outline of a car…but i can’t find it, nor can i figure out how to use the shape as a gmask within Action.

I can make the shape, add the softness but i cannot get it to behave like a mask.

Any suggestions how to do this?


Hi, this one maybe?
You should set the 3dshape to Media Projection.

But to achieve this effect nowadays I would attach a material node to my layer in action,
and do a lightwrap from there.

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Thanks PVR - yes…that’s one of the videos i was looking for…
.but i’m not trying to use it for lightwraps - i want to use it as a soft edged open spline mask.

Hi Adam,

In Action, start drawing your 3D shape. To create the open spline, click the FINISH button to the right of the UI. At this point it will just look like an invisible gmask spline. In the Gmask menu, Click ADD for softness or press SHIFT+A. This will create an open Gmask Shape with a solid edge. To soften the edge, Go to the 3D Shape controls and set the Gmask Transparency to FOR 3D SHAPE ONLY. This will give you a 3D shape with softened edges as requested.


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thanks Grant - i got that far - its after that where i get stuck - i wanted to take two copies of an input - give one a colour treatment, then use the 3d shape to reveal that treatment over the clean version of the plate.
Everything i tried just applied the white shape on top of the image and didn’t behave as a gmask would, even when using the gmask link.

maybe i’m imagining seeing this done!!

Hi Adam,

I think what you want is much more simpler then even using a 3D shape.

You can simply use the Gmask in Action to cut through one image to reveal another.

In my example, I am using the Gmask to cut a hole through the green layer to reveal the layer behind.

If you wanted the Gmask to act as a matte for the green layer instead of cutting a whole through it, just invert the mask.

As you can see, you do need to focus the Gmask Link on the target image surface and I would also check the priority editor in Action to ensure the green layer is on top of the background layer. Otherwise nothing will happen.

Hope this helps!

Here is a version of the inverted example.

Here is what I did to the Gmask settings…

Screenshot 2022-10-04 at 11.03.31

And here is the priority editor for both examples.
Screenshot 2022-10-04 at 11.03.15


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i think this is what i was remembering…just somewhere long the way my brain decided the 3d Shape was the way to get the open spline.

thanks Grant

Hi Grant

I can’t find the finish button anymore in flame 2022. It seems to have disappeared. As a workaround though I change the create tool to move and it does the same job.

Turn off Edit box? It’s there.

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