probem with Z combine node

Hello folks,
blur + Z combine = doesn’t work

I’m doing a futuristic office or sth. like that and I’ve put there three or four meshes that are supposed to look like neons (to be glowing). I assigned them a material with emit value, but that doesn’t make them glow. Now I wanted to simulate glowing via composition nodes, I put the “neon”-like meshes in one layer and rendered them separately, then I used blur and tried to join layer with the rest of the scene… The problem is that some parts of the meshes are covered by other non-glowing objects so I had to use Z combine node but in the final result the blurred part is gone so it looks like I didn’t apply any blur.
If I deduced right from what I saw it crops everything that is out of the original mesh area. So I’d need either to prohibit cropping parts that are not necessarily overlapped by anther object or use a completely different method (:D)

Any ideas?:confused:

can you post a blend or even just a screenshot?

zcombine isn’t going to work for this because you can’t blur the zbuffer…that is why the blur dissapeared when you used zcombine (all of the blurred pixels ouside the mesh area are still considered at infinity and far behind whatever wall you have). You are going to have to do alpha tricks…

if you either post a blend or mail it to me, I can help you set it up :wink: