Sunday, October 24, 2004

membrane shell code version "041024-membrane_deaf_01" uploaded to

hi membrane jitter folks,

i've made another round of edits --
built rudimentary activity meters, and elapsed activity, based on
hsflow of frame-diff.

now this shell will read in live and recorded video, and do some fading
based on activity.

you should be able to get it from here:

it's got 1.3 mb bc of 2 test videos included in the directory.
not necessary, and will be replaced.

if you make edits or add source code, please update the README.

this is too small for SourceForge, or CVS, but it would be good to
notify each other of mod history and ownership of source code, etc.

soon we should get test results on stability and speed on G5's either
at gt or harvard lab, or if chris can set it up, on his g5 in berlin.
it is not too early to try to build a standalone app, and test to see
what externals are needed and to test speed, robustness.

i'll post this email + README to our blog.


sha xin wei • 1-404-579-4944 • •

Saturday, October 23, 2004

schedule who is where when

Harry Smoak November 3-11
Yoichiro Serita November 3-11 (Oct 30- Nov 3 Vicenza? ; Nov 11-13 Paris?)
Sha Xin Wei November 6-11 (Oct 31-Nov 6 Vicenza; Nov 11-13 Paris) +1-404-579-4944
Chris Salter November 5-11
Maria Cordell November 6-11
Delphine Nain November 8-9 ?
Joel Ryan Amsterdam

mapping activity to 3 states


Let's say that these are the overlapping states as functions of activity:
Ghost state: when activity A or B close to 0,
Loner state: when activity A or B close to 1
Crowd state: when activity of A+ activity of B >> 1

Look at relative strength of A vs. B (measured not by ratio, but something more robust)
If A is more active, then perhaps we take motion data from A, and operate on live feed from B,
(and vice versa).

Use hysteresis (or simply smooth over time using line objects) to make state change stickier.

In the intermediate state, loner state, maybe we can cycle between (Yoichiro) fluid and (Delphine+Maria) smoke because for some parameter values, smoke can have watery response, and fluid can have smoky response (set heat diffusion high).
This cycling can depend on SOUND, perhaps, in which case jitter should READ (not just emit) some single parameter say in a circle-range [0,2pi] from Joels' code. In simple case, we can use elapsed clock (which in fact is already a function of accumulated total activity, so "time" essentially stops when no one is active the hall.)

At Van Nelle, we will tune the system so that 0 corresponds to residual light acivity when no one is moving, and 1-body is for 1 person's worth of "average" fidgeting. Dafualt parameters are already defined for the appropriate zmap's. (Maybe should use table, if we need a non-monotonic response curve.)

- xw

Tuesday, October 12, 2004

DEAF04 blurb

Checl out this link to the V2's DEAF04 website blurb about Membrane:
We'll want to put up better visuals as Nov 9 approaches, and update our own site with documentation during the show, Nov 9-21.

It could look beautiful. lighting gods willing.

- Xin Wei

Monday, October 04, 2004

Membrane Meeting

I'll be holding regular weekly meetings during the month of October for the
local Atlanta project team working on Membrane.

For this week let's plan on meeting Wednesday from 5:30-6:30 (EST) at TSRB
Rm 209. (Xin Wei, please join us via iChat if you are available.) I'll post
notes to the blog following the meeting.

On Wednesday I'll present updates from V2-- the technical rider, and project
plan-- and a draft research brief outlining objectives for the upcoming user
tests (dates TBD).


Saturday, October 02, 2004


Originally uploaded by xinwei.
This is a floorplan of the Van Nelle exhibit hall, with possible locations of 3 membranes marked in red. The rectangle to the left is a glassed-in waiting room, with 2 x 2 benches in the middle. There is a stairwell in between the two left-most proposed membrane locations (in red). The distance between two columns in a row is approximately 21', 7m.

- Xin Wei