Transparent outline across layer?

[MaxRavenclaw]

I'm not even sure how this technique is called. Basically, using transparency to show that one element is over another, like in the pic I attached (the gun in the right is over the one in the left). Is there a plugin or quick way of doing this in Paint.net?

[Eli]

Place your objects on different layers. Run the Boltbait's Outline Object effect on the upper object using the same color as the background.

[MaxRavenclaw]

Thanks for the quick reply.

That's actually what I tried here, but the results were a bit unsatisfactory, so I ended up just forcing transparency with a straight line.

 

It either led to this, when there was a difference in sharpness:

 

 

Or this, when the line wasn't straight:

 

In addition, this doesn't work if the background is transparent.

 

I was hoping there was something else.

[Eli]

Ok. Then try this :

Duplicate the layer with your upper object and make an outline (black) on one of these layers. Use the Hue and Saturation  Adjustment to make the entire outlined object black. Copy these black object to the Clipboard. Then go to the layer with the  "lower object" and use Boltbait's Paste Alpha effect.

[MaxRavenclaw]

Thanks again for the quick reply.

 

Sadly, the same thing happens.

I think it's an inherit effect of the outline plugin. It doesn't apply AA like when using a simple line. I suppose I can try applying AA after the fact, though, so these two methods you've listed can still be useful.

 

Pity there's no plugin that does it all in one step, though.