Ignoring a foreground object: Ideas?

I have a track I’m working on and it appears to be an easy track. However, at the key moment, a skinny object (like a thin arm) passes in front of the object being tracked (which is a large tree during a simple dolly).

This causes distortions in the splines since Motor is being confused.

Is there a way to “mask out” or ignore this portion of the larger object being tracked? Perhaps giving preference to the parts of the tree NOT being obscured by the arm?

Thanks for any ideas!

Scott

As per the previous reply, as for Tracking the Layer order is honored, layers on top always subtract from layer below.

Using the Track Matte overlay button (Viewer Controls) and Colorize active, displays the Mattes as used for tracking. The button is a tri-state button and clicking it a second time will display individual track mattes per layer selection. View individual track mattes in order to confirm the subtracting function per layer.

NB: The Mattes as out put for Roto purposes are not affected by layer order but by Blend Mode (Layer Properties).

—Quote (Originally by Scott Sullivan)—
I have a track I’m working on and it appears to be an easy track. However, at the key moment, a skinny object (like a thin arm) passes in front of the object being tracked (which is a large tree during a simple dolly).

This causes distortions in the splines since Motor is being confused.

Is there a way to “mask out” or ignore this portion of the larger object being tracked? Perhaps giving preference to the parts of the tree NOT being obscured by the arm?

Thanks for any ideas!

Scott
—End Quote—

As I understand it the tracker honors the layer order i.e. layers on top maskout or subtract on all layers below.

So I would do a layer for the foreground element and make sure is is above the roto element I’m tracking. Perhaps track the FG element or just manually key frame it depending on the shot.

—Quote (Originally by Scott Sullivan)—
I have a track I’m working on and it appears to be an easy track. However, at the key moment, a skinny object (like a thin arm) passes in front of the object being tracked (which is a large tree during a simple dolly).

This causes distortions in the splines since Motor is being confused.

Is there a way to “mask out” or ignore this portion of the larger object being tracked? Perhaps giving preference to the parts of the tree NOT being obscured by the arm?
—End Quote—

As I understand it the tracker honors the layer order i.e. layers on top maskout or subtract on all layers below.

So I would do a layer for the foreground element and make sure is is above the roto element I’m tracking. Perhaps track the FG element or just manually key frame it depending on the shot.

Jesse

Jesse,

Thanks for the tip. I’m going to try that. Take care!

Scott