Set Matte Effect Problem

mzomxs

Hello,

So I'm making an animated object and I want it to be invisible on spesific area. I dont use mask because the mask will follow the movement of the object. I want it to be still (the invisible area), so I use the set matte effect. Unfortunately I'm facing some errors.

I followed these steps based on the video I watched:

1. Create a plane layer, mask it to shape the desired area that I want to be invisible
2. Apply the set matte to the moving object
3. Set the source to the plane layer
4. Change the blend to add

On the tutorial video I watched, the moving object will be invisible on the plane area. But in my case, the object is invisible even after it pass the plane area. Does anyone know how to fix this? Thank you

Triem23

Close.

RIght click the plane you've masked and convert it to a composite shot. Move Masks and Effects.

In the Set Matte effect change the Blend from ADD to REPLACE.

mzomxs

It works! Thank you so much! 😄

https://community.fxhome.com/discussion/comment/162776#Comment_162776

Triem23

Ok, a little bit of "why" for you.

Effects with "Source Layers" (like Set Matte) look at a layer BEFORE adding effects/masks. Moving the masked plane into a Comp "baked in" the mask. Otherwise the Set Matte would have seen the raw plane without the mask (so, a rectangle).

With the Set Matte the ADD blend adds a displayed area. Since you're trying to remove/hide a thing add is the wrong mode.

A SUBTRACT obviously hides things. A Subtract blend might also do what you want, although you'd have to click the Invert box in your case.

REPLACE well, replaces. In this case, since the transparency is baked into the Comp, replace works for you.

mzomxs

https://community.fxhome.com/discussion/comment/162779#Comment_162779

Thanks! I actually used the subtract blend because the replace blend add some kind of black box on top of the moving object. Is that the right thing to happen or I'm possibly doing anything wrong?

(By the way, yes, the subtract blend works just fine)