'Cutting out' part of a lightsaber blade

Hey everyone, I'm sure this has come up numerous times, but one more time can't hurt. I am doing a little saber FX test using Ryan W's AE method and I am facing the side and I stab the saber behind me, thus for about a frame you can see the tip and the hilt, but not the middle, which my body is blocking. Now, my question is, how would I hide that part in AE? I am assuming I have to use some sort of mask, but how do I get it so when I start adding the effect, it isn't made to that mask as well? And how do I just block out the blade and not my the entire peice of film??

 

Yes, create another mask on the same layer and set it's mode to Subtract. This will simply remove part of the saber mask. Remember that when you don't want to use it you should keep the mask out of frame.

 

Ok, it was the subract that was throwing me off. When I don't use it I just set the opacity down to 0 and it seems to work ok. Thanks!

 

Do you do this to the core before you do the triple duplicate?

 

Yes, to the core. Then if you actually use a blur filter to make the auras later, the glow will spill properly.

 

"triple duplicate?"

How about triplicate?

 

lol. I just realized that.