Masking simulations

[Stefan Cargoski]

Hi community.

I have some questions regarding how to correctly mask simulations.

In the first example below with layer 3 (oragne colour), ball action simulation is applied, and I tried to create a mask with my solid, but nothing happens. I tried with this mask, because it gives options for feathering.

In the second example I precomposed (Green layer) the simulation, and again tried to make a mask with the precomp, but masking didnt work.

Witht the 3rd option, I did a track matt, and the masking worked so I got my star shape and bubbles masked into the shape. But the edges are hard, and no feathering options are available. 

So what is the best method to mask a simulation, and be able to feather the hard edges?

Thank you.

[nishu_kush]

Thanks for writing in.

The mask doesn't seem to work because the balls are scattering too much. Try lowering the Scatter. If you do not want to lower the Scatter, Pre-compose the layer with "Move All Attributes into the New Composition" Selected and apply the mask on the Comp layer.

Let us know how it goes.

Thanks,
Nishu

[thepixelsmith]

I believe the order of operations in AE is still, Masks, Effects, Transformations so Masks will affect layer source content, not the result of effects, especially the ones that generate graphic content. The only way around that I am aware of is to assign the mask as an FX mask in compositing options.

[thepixelsmith]

Option 1:

Masks apply before effects do so they are masking the source layer's content not the results of the effect.

To create a mask that applies to an effect you have to use the effect's Compositing option. They are located in the Timeline (and only in the timeline) as the last property group for the effect. Just click the plus sign to add the layer mask as an effects mask. There are limitations with this approach: You will need multiple masks if you also want to mask the layer's content and feather doesn't work the same way with effects masks.

Option 2

Your second attempt seems to have failed because you left the effect on the comp layer rather then moving it into the new comp. I assume you used the Leave all Attributes option instead of the Move all Attributes option in the pre-compose dialog box.

Option 3:

Your third attempt with the track matte. To soften the edges of a track matte apply a blur effect to the track matte layer.

[Stefan Cargoski]

I will give all this a try and update the results.

Kind regards.