BSA227, car bomb, after effects, 27 July, 2016

window- tracker
tool helps stabilize camera so you can composite in effects quickly without doing it frame by frame
select footage file, then click track camera.  it will analyze background, which you can watch in 3D camera tracker panel to left of screen (if you're in standard view)

The crosses mean it has a 3D space in a 2D film.

moving mouse finds three yellow points to create tracking space to animate on
can also click on 3 balls to create your own flat space

Text should stay with floor like it's been spray painted there.
3D camera tracker

Tracking info can be used multiple times.  Text can be changed, same as Photoshop, by highlighting text and rewriting word on the screen.

multiple layers of text can be inserted by going back to xs screen- highlight moving file, then select 3D camera tracker and go.  to move text, select arrow, hang or rotate tools at upper left or choose shortcuts

create null_ select a point to attach things to if you can't find three points and bullseye.  click on one point, right click to select create null
create a solid in same way to see how well things stick to that point during the tracking shot
drag and drop bomb footage to just above null layer
rescale explosion by selecting pan behind tool
attach bomb to null layer by turning bomb to 3D layer, parent swirl creates line that can be pointed to null layer. hold shift (as per onscreen directions) to attach it to null layer.  select bomb layer to move it around and scale it up so it fits the car.

mask it with the pen tool- connect four dots in a box around the explosion.  limit the top of the explosion so it looks like it's hitting the roof but still going over the pole.  next is a mask on top of a mask to achieve a behind the pole effect.
change mask 2 from add to subtract

The dust layer is problematic:  Even with a feather mask, there is still a strong line below it.  Maybe if I move it forward, away from the shadow, it will be less noticeable.