Last Month I was fortunate enough to work on some VFX shots for a local company- Flip 11.  My tasks were to:

1. Create “a perfect storm” of clouds coming in
2. Sky replace the footage
3. Track and Match Move the clouds
4. Roto out the people in the scenes
5. add additional rain elements if possible
6. Screen replacements
7. Add ight flare effects to sell the brightness and contrast of the hot blistering day.
8. Composite in more steam/smoke
9. track the car hood and match move the steam and smoke.
10. Deliver within 48 hours.

I used mostly particular to create the cloud animation in layers. I was lucky enough to have lots of stprm clouds immediately after picking up the footage to use as reference material.

Particualr was great but also VERY resource intensive. Im running a majority of my work on a 8 core i7 with 2gb of video ram and had a hard time getting the particles to preview.

I additionally used several stock photos and even an instance or two of video co pilots “real Clouds” pack from like 10 years ago! (never throw away old stock).

For the tracking most of it was dove with the tracker but due to crossing the area of tracking I had to manually track the horizon point.  I had to blow out the scene just to see the horizon.

Additionally I had a few people crossing the scene that needed roto and one main one with curly hair that made things a bit challenging.

The sky was no where near a clean mattable color so I hade to rely on extract and a few passes to seperate the backgrounds.

In the second scene alot of that just wasnt possible and I had to layer a few masks in the trees so i could better Sell the trees withanother foreground layer of it.  Each scene didnt really have a horizon track point so I had to pick any feature that I could make work. A tree branch, some mounttain etc.

once the clouds were created in several layers and animations I pumped each one out as its onw alpha matte and recomposited them into all the scenes. So i eneded up creating about 8 layered weather systems and reused those.

Screen replacements were done with Mocha. I love using screen replacements with mocha. Its quick and its easy and it works!

The lense flares were creates with video co pilots Optical flares, and each exported as a tintable matte. Most were used at a very low opacity just to give a little extra bump.