Luma Matte question

[mschri]

Hello,

I seem to be having trouble with using the luma matte function. As you can see in the screenshot, I have applied the luma matte under the layer I want the luma matte to apply to. I am not getting the result I am looking for. The result I am looking for is for only the gun to be visible and the background to be masked out. I  have messed around with the blending mode to see if I get an effect but as I expect nothing for what I am looking for. I have also switched the track matte to a invert luma matte but it also didn't help. Please if anyone has a solution for me to solve this problem, I will be greatly appreciated.
Thank you!

[Dave_LaRonde]

Now, you DO have those two layers set up so the upper layer provides the transparency, correct?  I see you've applied effects to that layer.  If indeed the upper layer provides the transparency, precompose it to preserve the proper Ae render order.

And kill the blend mode on that layer -- it won't do you any good.

And if you're unsure how to use track mattes, perhaps this might help:

Alpha and Luma Mattes in After Effects CC

[mschri]

Hey Dave,
To answer you question, yes. The layer on the top of the list is the original layer I wish to have pass through the layer that acts like a mask below it. In addition, the layer below it has effects applied to it so I can have a black and white image for that layer. The bottom layer has the gun object in pure white and the background in pure black. Here are some addition images that may explain my issue better.

[Szalam · Accepted solution]

Your layers are in the wrong order. The luma matte goes above the footage you want to cut out.