Additive lines

<img src="http://dl.dropbox.com/u/1378330/Untitled-1.gif">

Hey. So I'm trying to get two shapes to interact as shown above, but dynamically. I basically want to show an area of effect around a unit, but when you build two units close enough that the AOE overlaps, they combine, they don't just overlay each other.

Anybody know how you could go about this?

Here's a good way to do it, without shaders:

http://www.mediafire.com/?1d4y4nzymtw

And with shader:

http://www.mediafire.com/?izujmygkjzz

And if you need the middle to be transparent, you can use the Erase effect with it.

you need to place 4 copies of the objects silhouette behind both of them displaced 1 pixel in each of the 4 cardinal directions. at least thats what the outline shader does.

or you can of course just use the outline shader. if thats not a problem.

Yeah, I threw the first one together, so naturally it's not accurate.

I was mostly just trying to show that it didn't need to be a solid color that way.

Cool beans. Thanks guys, the outline method should work great