Particles in Negative Z-Space

[Matt Faw]

Dear all,

I wanted to share a few recent experiments using particles in negative z-space. I was blown away by the falling ash scene in Avatar (and the rain in Meet the Andersons), and have been looking for a chance to play in that territory, myself.

Since particles can easily exist in that space without the risk of edge violations, they seem to be a useful way of keeping the negative z-space active. Of course, a deep particle system may also have extreme differences in convergence, but the small size and some movement seem to keep the brain filling in the gaps, and pulling off feats of convergence, almost by assumption. What I mean by that is: still frames of some of these extreme negative depth particles aren't easy to converge, but when they're moving, my brain is so busy making sense of it all, that it fills in any gaps, and everything makes relative sense. This is probably especially true of the last shot in the following sequence:

3D Z-Space Particles tests - YouTube

Most of the above was generated in 3DS Max, using David Shelton's 3D Hippie Stereocam rig, and composited in After Effects. Of course, I recommend seeing this in HD, full-screen.

I'm curious about y'all's experience in this territory, what experiments or jobs you've had to deal with this, where the particles just didn't work, or ways of approaching them that is novel and exciting.

[Paul Newman]

Hello Matt,

I'm having huge difficulty resolving comfortable 3D from the posted clip - I've tried reversing L&R - maybe I'm missing something, that's somewhat by the way - I see where you're going - I too have made some particle based material which technically has edge violations, but still works OK - my main effort has been towards getting the balance between the various elements right - I think short blasts of extreme negative objects/particles work fine -

There's this music video I made purely as a particle matte/depth test, particles built in Nukex with a stereo rig and then combined in Edius - some of the shots have the "woozy" effect

You maybe saw this before:

Xufei Yang Bach Violin Concerto G minor Snow Mix 3DSBSa - YouTube

and this little graphic which is quite 2D, except for some negative space short lived particle;

Short 3D Title test - YouTube

Paul :-)

[Matt Faw]

Originally Posted by Paul Newman

Hello Matt,
I'm having huge difficulty resolving comfortable 3D from the posted clip

Sorry about that, Paul. I don't know why that would be. It plays fine for me in anaglyph and SbS.

Your samples are interesting, because you play with depth, but then you use 2D transitions and effects, like the blur vignette, blur flash dissolve, and in the Grass Valley clip: staticky TV effects. I wonder if there are new ways of communicating the same attitude as the 2D FX and transitions, while staying within a 3D vocabulary? I find that each time the 2D FX arise, the clip loses its 3D "thereness", and some flow is lost, thereby. We don't often talk stereo aesthetics here (beyond "roundness" or depth), but I think there's a whole new language to be worked out in 3D, that just can't rely on most of the old 2D tricks. My 2 cents.

[Matt Faw]

Dredd 3D makes great use of particles in the negative z-space; most scenes have some dripping water or shattering glass or particulate matter floating about, which really helps keep the depth stay alive. I raised the question of stereo fatigue in feature-length movies, and Dredd was perhaps the first film that the 3D stayed fresh throughout, I think partially due to those particles.

Also, Dredd varies between decent depth for the main action, and then even better depth for the drug-high sequences. It is worth seeing the movie in 3D for the slo-mo drug sequences, alone. They are really spectacular and, I think, bring in some new vocabulary to 3D. Along with the Step Up movies, Dredd is probably the best live-action stereo I've seen since Avatar.

[Carlton Bright]

Matt,
Yes, I agree there is a new language for 3D, and your thread throws some light on it I think.
I think it will be a new branch, and the traditional use of video will just be a point of departure.

I think it is more akin to music and music composing, than to narrative story and film and video making.
Intersting thread and thanks for the DREDD scene head up.
Carlton

[Matt Faw]

Here's a web short about Dredd's use of high speed photography (Phantoms), in context of 3D:

https://www.youtube.com/watch?v=hbukllyrrBs

I think super slo-mo is a perfect fit for stereo.

BTW, just saw Silent Hill in 3D. They also used a good deal of particles in negative z-space, but not nearly as effectively as Dredd. In particular, the exteriors at Silent Hill are marked by drifting ash particles, but the filmmakers also added so much smog-like atmosphere that the depth of the particles and the rest of the image is compromised.

Likewise, I noticed in my tests that when I had too much motion blur on the particles, that the left and right views would not fuse, and the depth would be lost. I'm guessing that the brain really wants to create a 3D image from the L/R sources, but when there's not enough info to form one clear particle (because of blur or fog), then the depth is lost. It's perhaps something like the nose on my face: it's always present in my vision, but because it doesn't change, or fuse with the other eye's view, then it's just ignored.