I really need your help on this one!

What I'm trying to do: Apply an effect in a small portion of the image in only one of the cameras in a multicam.

To do that I copy the video from V1 to V2 and then on V2 I apply Animatte to a make a mask. And then on top of Animatte I apply the next effect so the effect gets applied only to the mask of Animatte. Not so sure if this strategy is the best, would love to hear alternatives.

The Issue: I'm having big transitions (2 seconds) between the cameras and during the transition I can see the mask border of the mask! So frustrating. I'm trying to get rid of the visible mask during the transitions but don't know how.

PS. I was thinking of applying that effect directly to ISO3 (its the camera from the multicam that needs the fx) but that means I would need to make a new Group and do the Multicam edit from scratch so doesn't sound like a good strategy.

I think you're generally on the right track. I would usually apply the required camera effect below the Animatte effect, but if it works your way, then that's fine.

Be aware that stacking some effects on a higher layer will result in it effecting the layer below. Very frustrating and one of the limitations of Avid's effects architecture.

Wherever possible, try to promote your effect to gain extra features. So, for example, rather than stacking (say) a positioning effect on top of a superimpose effect, promote your position effect. This essentially turns it into the 3D Warp tool, which has opacity controls built-in. 

In fact, I would advise you use the 3D Warp tool as the basis for most of your effects, and only add those effects which the 3D Warp tool doesn't cover.

In terms of your problem, I'm not quite sure what you are trying to achieve. I'm assuming you've applied feathering/softness to your Animatte. When you say 'big transitions', do you mean you are dissolving(?) from the camera without the effect to the camera with the effect?

In many cases where you have multiple layers that have to dissolve in/out of a base layer, I've seen people apply the transitions to all the layers. This causes these layers not only to become increasingly transparent to the base layer (as you would expect), but also between each other, which might not be what's wanted. The way around this is to collapse these higher effect layers into one. There's a Collapse tool available to do this, which turns your stack into one layer (effectively turning it in to a submaster effect). Once you have your stack as one submaster layer, you can disslove in/out.

Hope this answers your question.

Collapse both tracks into one...

Thanks that did it! I just found this video and it is exactly what I am looking for

https://www.youtube.com/watch?v=EdF9JA_3q8k

Bruno M:

I think you're generally on the right track. I would usually apply the required camera effect below the Animatte effect, but if it works your way, then that's fine.

Be aware that stacking some effects on a higher layer will result in it effecting the layer below. Very frustrating and one of the limitations of Avid's effects architecture.

, you are right! I totally missed that! The correct order is apply the effect in V1 and then Animatte on V2! 

What I was looking for is the Collapse tool, I was totally unaware of it! Life savior