Wednesday, June 7, 2006

3-D With After Effects

It's been hectic around the household lately as I've started a new position at work, one that has finally moved me from 10 years of graveyard shift 180 degrees to a normal daytime office schedule. I'm still adjusting to the change and am not getting the best night's sleep.
As such, I'm on pause with the movie after having completed the first act, and have been making demo discs as a rehersal for the final post-production phase.

When I started the project, I was planning on using a freeware program called Stereo Movie Maker to convert the left/right movies into final anaglyph and interlaced 3-D; however, I discovered last weekend that not only does Stereo Movie Maker use the old Video for Windows API, which imposes a 2GB limitation on files, but it also has a habit of converting my footage rendered at 1.2 pixel resolution (for 16:9 widescreen) to .09 pixel resolution DV. I end up with a 720x480 image that is taller than wider, and everyone is stretched out.

I have also encountered a bug in Premiere that renders black for about half of the movie when using the Huffyuv 2.1.1 codec (upgrading to 2.2.0 only made matters worse). I was forced to use a frameserver to output the left and right movies from the Premiere timeline, and then bring those files into After Effects and apply the "3-D Glasses" filter, thus compressing the movie 3x - once on the raw Poser data>editable clips, once from Premiere>conformed movie and then again from After Effects>DVD/Windows Media/etc.
However, with the help of one of the production guys at work I found an even better method: importing the Premiere project directly into After Effects, selecting all the layers and using the Pre-Compose command to flatten them into a virtual movie clip, then doing the same with the right eye version. After I bring them both into the After Effects timeline, I can apply the 3-D conversion without re-compressing the video. Now, we go from raw Poser data>Huffyuv clips>final output (DVD).

I've also discovered that the 3-D Glasses plugin for After Effects is virutally useless - no matter how much I tweak it, I cannot get the colors to the right phase of red and blue to be filtered out by the anaglyph glasses, either on the PC or on a TV screen. I wanted to use Stereo Movie Maker initially because it uses a special algorthm to produce a "half color" anaglyph which reduces retinal rivalry caused when a character wears red or blue clothing. Retinal rivalry refers to the phenomena that occurs when the red lens of the glasses makes red objects appear "white" and the blue lens sees them as "black". The half color method converts the left eye to grayscale and then siphons off the red channel, allowing red colored objects to be perceived as grey.

Without Stereo Movie Maker, I'm forced to use another After Effects plugin called Set Channels, which allows you to use the red channel from the left eye and superimpose it with the green and blue channels (creating a cyan channel) of the right. By using telling the plugin to use the green or blue channel from the left eye to extract the red from, instead of the actual red channel, it produce something closer to the half color anaglyph. The result is much easier on the eyes and works best on a PC monitor, and relatively well on a television set.
And, not satisfied with the opening title sequence yet again, I created a new version in which the main title actually shoots out at you. It's more impressive than the previous design, in which the titles started out a bit off the screen and slowly zoomed out. These new ones start right at the 2-D plane of the movie screen and zip out at you in about half a second. It's much more dramatic.