[Adam Browne]

That did it! Thanks! This is my first foray into expressions… so much more to learn.

[Adam Browne]

I thought the same thing about the “72” coincidence, so I rescaled the images in PhotoShop and did it again with 1 ft = 100px, and it looked exactly the same. So it seems to be arbitrary, as long as I’m consistent.

If anyone else tries this, I recommend using the ratio 1ft = 100px. The file sizes are manageable, and the conversion is very simple. For example, if my AE camera is 600px away from the subject, I know to put my real camera 6 ft away.

[Adam Browne]

I think I have some answers. Basically, the idea of doing 3D pre-viz in AE works! The pixel-inch ratio is arbitrary, you just need to be consistent. Check out this test:

I used my HVX at it’s widest setting (=32.5mm lens) to take a shot of some walls in my apartment. I picked a point in the room to be my ZERO point (x=0, y=0, z=0) and then I measured EVERYTHING (mostly importantly, camera placement/angle). I drew up some sketches of the walls (to scale) and brought it all into After Effects. For this test I made 1 ft = 72 px.

I set-up everything in the compostition by the measurements I made in the real world, and this is the result.

[Adam Browne]

Thanks, Dave. Hmm… I’ve been doing some tests. In the camera settings window, I can select between inches and pixels as units, and when I divide those numbers (regardless of comp size) I get 72 (px/in).

Unfortunately, I don’t own a camera with prime lenses to test with.

I’ll try a few more things and report. Maybe there’s other folks out there who could benefit from this knowledge.

[Adam Browne]

Thanks for the pointers

here’s two questions I still have:

first, is CC-Ball action truly 3D, or does it just appear that way?

second, does Zaxwerks 3D Warps plugin work with video layers. I don’t see why not, but all the examples I’ve seen use stills.

[Adam Browne]

Thanks. I’ll take a look at it.