Question for Fusion users.


I’m pretty new to DF coming from combustion and After Effects and I’m trying to do something that would seem really simple, but I can’t get it to work.

Here’s what I’m trying to do;

I have 2 separte pieces of footage, i.e. forground plate and background plate. I have a separate alpha channel plate that I want to use to comp the forground over the background with. This may be something really, really simple to do, but I’m playing with the free demo now untill my purchased copy shows up…and I don’t have any user manuals. With that in mind…I’m still trying to get used to the “node” structure when I’m really used to the layerd style as in AE. In AE this is a 20 second process and whalla! done.

Can anyone give me a hand here?

Thanks in advance!


Hi there,

Load up your foreground, background and alpha plates into seperate loaders.

Select the foreground loader, create a bitmap effects mask (right click the yellow loader title bar under the tools tab. Select the Masks tab (should now have a small indicator on the tab telling you there is something there). Click (or double click) on the title bar “Bitmap 1” to view the controls. Drag and drop the alpha loader into the ‘drop tools here’ box. When you view the output of the foreground loader, the mask should be in effect.

Use the Merge node (Brown input is background, green is foreground) to composite the two together.

A couple of minor things… use the invert button in the mask controls to switch the affected area from the alpha. If you have a greyscale image (I think colour works as well??) without a dedicated alpha channel, select the red (or another colour) channel under the foregrounds mask controls. This will give a similar effect to an alpha channel (good for using greyscale images as a mask).

Hope this helps,


Justin W. :slight_smile:


Justin W,

Thanks alot man! :beer:




Another way, that would offer a bit more control is to have a matte control tool after your forground. Plug your alpha layer into the green arrow on the matte control.

Set the matte control to “matte combine” the appropriate channel.

This now allows you to shrink or expand the matte, blur it etc. Also it gets rid of the hidden connection between the alpha loader and the foreground loader. Makes it simpler to see what is going on later after you open the project after not seeing for a few weeks. :wink:


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