I’ve written a chapter in the following book: “Experiments in Digital Puppetry. Video Hybrids in Quartz Composer”. It involves the material on this site and elsewhere that describes real-time video processing and the use of Quartz Composer in performance. I feel quite proud to be in such interesting and diverse company. The chapters on digital puppetry are really welcome. The subject deserves a book all of it’s own!

I have a chapter on Digital Puppetry and real-time performance systems (including Quartz Composer) in the following book:

Transdisciplinary Digital Art. Sound, Vision and the New Screen
Digital Art Weeks and Interactive Futures 2006/2007, Zurich, Switzerland and Victoria, BC, Canada. Selected Papers
978-3-540-79486-8_1
Editors: Randy Adams, Steve Gibson and Stefan Müller Arisona

I’ll post more details and some excerpts asap.

If you are in a position to, please order the book for your college or local library!

A second version of my ‘tiger reflections patch’. Now with a simpler interface and Noise Industries ‘FXFactory’ ready!

The patch is simplifed and slightly more reliable than the previous version. The generated image can now rotate without producing artifacts. The gradient setup is now automated. Less control but simpler. I have done this to create a test composition that works in ‘FXFactory’ - which is very simple to use. It really unlocks another realm for Quartz Composer developers.

Link: http://www.noiseindustries.com/fxfactory/

A second version of my ‘tiger reflections patch’. Now with a simpler interface and Noise Industries ‘FXFactory’ ready!
The patch is simplifed and slightly more reliable than the previous version. The generated image can now rotate without producing artifacts. The gradient setup is now automated. Less control but simpler.

The patch does a simple thing of producing an ‘aquafied’ circle. I created this patch when I was exploring masks and how best to create a circle using the current Quartz Composer toolset. The patch contains some useful techniques working between pixels and Quartz Composer units. It is also an exercise in ‘pixel based positioning’. I am sure the visual effect can be improved upon, but I quite like the principle of instantly produced graphics using quartz composer. I followed several online tutorials for producing aqua styled graphics - then simplified the process. I reckon quite complex aqua graphics could be produced in this way, like widget graphical elements etc.

Some Issues

The accuracy of positioning of bottom gradient may need improving. Hence the ‘tweaks’
Better control over how the bottom gradient is generated. The rules seem to break down at smaller sizes. Fun though.

Download Link: iris_quartz_composer.zip
Some Notes

The patch is quite simple to use. For a recent digital puppetry project, I connected the iris radius to a the output of a midi foot pedal so I could create scene transitions in real time. More of that elsewhere.

The patch demonstrates a number of useful ideas: pixel to unit conversion, creating a circle (using the hole distort patch), masks and the ’source atop-in-out-wave-it-all-about’ patches.

Some Notes on Custom Patches, Hidden Patches and Core Image Units

My original patched originally used one of the hidden patches ‘CICheapBlur’ that you can enable by following instructions here.

See http://fdiv.net/2006/09/19/61-hidden-patches/

For the download here, I have replaced the ‘CICheapBlur’ patch with a gaussian blur - so there shouldn’t be errors if you do not have the ‘hidden’ patches activated. This effects performance slightly. With custom core image filters appearing in the QC patches pane, I am sure it is quite possible to distribute compositions that will not run on other people’s machines without the custom CI filter. There seem to be more useful custom patches appearing on the scene with a number of excellent ones from Boinx. I hope a useful installation mechanism can be constructed to distribute the pre-requiste elements for custom patches.

Link: http://www.boinx.com/chronicles/category/quartz-compositions/

I do not intend to post the full patch as it is very dependent on other media, the wii controller and the Behringer midi controller, but you can view the root of the composition in the image below. I have split some of the more useful elements up and will be sharing them in other posts. I attempted (and will develop further) the idea of having a separate ‘buses’ for scenes, effects and transitions - a little like the way (I think) quartonian (and other vj-ing tools) work.

Image (1.8mb large): Screenshot of Root of Performance Composition

The project used some of the following ideas:

• instant chroma-keying and garbage matting of a performers blue face and the compositing of a hybrid character with live mouth and controllable pre-recorded eyes into multiple scenes
• midi control
• nintendo wii remote control of a virtual character (this meant I had to write a custom cocoa application to host the open source darwiinremote.framework ‘)
• Quasi 3D (or 2-and-a-half-D) effects derived from 2D frames - I’ll post some movies of this.
• Depth of focus and pulling focus effects
• Dynamic real-time titles

Some Images and Commentary

A fuller walkthrough of the final images with a commentary can be found here:

Screenshots and Scene-by-Scene Descriptions Link: http://www.daisyrust.com/quartzcomposer/moocher/

Image (above): Prototype of the Garbage Matte and Chroma-Keying Patch

Download Link: garbage_matte_bluescreen_demo_002.qtz.zip

This demo patch makes uses of Sam Kass’s excellent core image kernels available here:

Link: http://www.samkass.com/blog/

Images (above): Behringer BCF2000 MIDI controller controls scene sequencing and properties of various screen objects and parameters in real time

Image: Real-time Mouth / Recorded (controllable) Eyes Composited into an Image in Real-Time

Full credit and copyright acknowledgment to the Fleischer Brothers Estate for frame grabs and stylistic inspiration.

Download Link: movie_thumbnail_viewer_001.qtz.zip

It works in principle but there are a number of issues I’ll go into in a moment. It is an early version of an idea that could produce instant time-lines, retrospective after-the-fact storyboards, onion skinning and other video frame manipulations. I use it to visualize the flow and movement of time-based imagery and to produce illustrations for lectures. It is the kind of process that makes Quartz Composer a pleasure to use. To produce such a layout in Photoshop would take a good deal of preparation and layout work. I love the grid layout and the visual effects produced by this patch - as images in their own right.

Basic Operation

You set the path to a quicktime movie.
Make some basic choices about number of frames per row, number of rows (you need to enable / disable each row as needed)
Set the time interval / frame shift to jump on each row.

Image (above): Frames demonstrating early pioneering rotoscoping from Dave Fleischer’s “Snow White” (1933) with Betty Boop and Cab Calloway (full copyright acknowledged).

Image (above): Sequences from Bill Plympton’s “Your Face” (1987) (full copyright acknowledged)

Some Issues

Here are some of the important issues that need to be improved:

• Performance.

The patch runs slowly. I am sure you could do a similar thing programmatically with QTKit that would be much faster in the generation of the rows / thumbnails. I may even have a bug / design flaw where each row gets iterated more than once.

• Manual Tweaking

It is always a design goal for me to have no manual tweaking necessary, for a composition to do it’s work with the minimum amount of set-up. This patch needs more work in this regard.

• QC Bug - Some codecs produce unexpected results [bug submitted]

It seems some codecs (I forget which from my tests - I mentioned it on the qc-dev list) produce unexpected results. i.e. only two different thumbnails are generated and they then alternate across the sequence. Some sizing / aspect ratio issues of the thumbnails when the viewer is resized

I have fixed this issue on other similar patches I have made - but have yet to implement the fix here. This patch would benefit a rigorous going over. I’d love to hear from anyone who finds it useful.

Additional Details

Images (above): the optional ‘info’ panel and math patch. This part of the composition is interesting and the maths contained there-in could for the basis for a future improved implementation.

Image (above): The basic macro with most of the important published ports

QCWii is an application that lets a user connect a Nintendo Wii Remote to the mac and control a simple teapot.

It is a proof of concept for a digital puppet controller. The final project controls a face - where the mouth is real-time video and the eyes a pre-recorded video loops that can be controlled from the wii remotes buttons. Please see the following website for more details and the project write up.

Link: http://ellington.tvu.ac.uk/ma/computer-arts-major-project/

The source code demonstrates the following:

• how the darwiin-remote framework can be used to control a 3D model in a simple Quartz Composer patch.
• how cocoa bindings work connecting UI elements, code and published keys from a quartz composer patch.
• a crude ‘full screen’ mechanism.

Many thanks to Jasen Jacobsen for advice on how to make the animation smooth and to Hiroaki for the ‘Darwiin-Remote’ framework and project.

Link: http://sourceforge.net/projects/darwiin-remote/

Usage

To connect to the Wii Remote: press button 1 and 2 on the wii remote so the lights flash, then click ‘Connect with wii remote’ on the preference pane:

To activate sensor tracking: click ‘Track Motion Sensors’ on the same preference pane.

That should be it. Most of the buttons on the Wii are connected to do something in the Quartz Composer composition - if only signal a connection to the patch.

• The cursor pad moves the object, left, right (x axis), forward and backwards (z axis).
• Buttons 1 and 2 rotates the object around the Y axis.
• + and - scale the object.

It is acknowledge that both scaling and translating on the Z axis is probably not as useful as moving up and down.

To exit full screen mode - press SHIFT - F on the keyboard.

Some Additional Information if you wish to edit the Quartz Composer Patch to do something other than move a teapot around

To find the QC composition:

ctrl-click on the QC-Wii application ‘view package contents’ and dig down to ‘resources’ that is where the QC patch - wii_to_qc.qtz - lives. You can (carefully) edit that composition to do something different other than trigger the text display and move the teapot… Just don’t change the name of any of the root level published port ‘keys’:

Image: The crucial published keys that bind the patch to the wii remote via the application. Do not change the published name of these - or the application will break
If you edit that composition, save it. Then when you re-launch the application, it will use the edited composition as it’s source.

This way you don’t need to use xcode or re-build the application.

The qc patch needs to run inside an application wrapper. The application handles all the blue-tooth connection wizardry provided by the wiiremote-framework, the calibration preferences etc and toggling full screen. So you can’t simply edit the composition and preview it using Quartz Composer itself and expect the WiiRemote to connect.

Ian Grant January, 2007

ian [dop ] grant [at ] mac [dop ] com

Here we go! I did this once then failed to remember how I did it - and I’m not surprised - because the functionality to attach a speech command to an application specific key-press can only be accessed by SPEAKING the command “Define a Keyboard Command” - highlighted below in the Speech Commands window.

After speaking the command - the interface below appears letting you assign a key press / key combination:

Then main “Define keyboard command” window lets you associated the key-press with a spoken phrase. An option lets you limit the Speech Command to a single application (the current frontmost application at the time the command was spoken) or to be available in all applications.

So: with Quartz Composer as the front-most application, invoke the “Define a Keyboard Command” Speech Command: I created speech commands for the words “Bored”, “Ecstasy”, “Frown”, “Smile” and “Wonder” and mapped them onto key-press “a” through to “e”. You can see them listed here in the “Speech Commands” window:

Then: I created a simple Quartz Composer composition attached here: with keyboard patch - that did stuff when letters “a” through to “e” were pressed: the demo presents text but you could easily set up commands to control video playback, switch between images, attempt interactive stories, etc… .

The Quartz Composer patch working:

Download: VoiceTest.qtz.zip VoiceTest.qtz.zip

Switching off all unnecessary speech “Command Sets” and calibrating the microphone (every-time) increases the reliabiliy of “Speech Commands”.

I intend to test how reliable ‘continuous listening’ is with a dedicated ‘line-in’ microphone with different voices speaking commands. I’ll report back.

*******************************
Ian Grant
Lecturer in Digital Art
*******************************

Download link: quartz composer video matrix test files 001 - 003

Notes: These are patches in development and (except patch 001) need some tidying - the published parameters are slightly out of order on 002 and 003, but you should get the principle from patch 001.

I have been wanting a patch that does this for a while and these are really just a proof of concept and may not be the most elegant solution. There are some limitations.

Limitations
The number of X tiles (columns) can be determined interactively. Unfortunately at the moment, the number of Y tiles is fixed. If you wish to add a row you must edit the contents of the “3D Transformation” patch and add new copies of the highlighted patches (indicated below), edit that names of published keys, plumb them in (following the pattern of the others - at this and the parent level) and set the Y position of the new row. Pain. But okay if you know what size of matrix you need.

For convenience, there is an image source that switches between camera input, images and a couple of movies - you will need to remove my movies and add your own.

Development - motion detection / computer vision
I have an idea (maybe wrong) that a static matrix like this could be used as the starting point for a motion detection / camera vision thing. Imagine if you processed the video (desaturate, detect outlines for example or use the “flood fill” that appeared on the quartzcomposer-dev list recently) and had something like a kernel that could sample each cell in the matrix and output a value or a boolean dependent on the white / black balance. I don’t think the core image kernel in quartz composer can output anything other than an image - but a kernel possibly can when used in core image in a cocoa application. Interesting.

Download link: quartz composer video matrix test files 001 - 003

Download: tiger_reflections.qtz.zip

A Quartz Composer patch that will automatically produce a cool, adjustable reflection from an image, text or video input. The style is familiar from Tiger applications, particularly “Front Row” and Keynote. It is a visual style echoed across Apple’s branding and is slightly cooler than a simple drop shadow.

Control Parameters

Most are self explanatory but here are some notes:

Color: this controls the background, the ‘fade to color’ of the reflection gradient and the ‘fade to color’ of the block that fades the reflections
Gradient Point 1 and 2: This numbers control the falloff / distance of the reflection The numbers relate to the size of the image measured in pixels. To get recommendations on what values to use select Gradient Advice.

Currently the recommended values are calculated like so:

Gradient Point 1: image height (px) / 1.7
Gradient Point 2: image height (px) * 1.5

Gradient point 1 should be smaller then Gradient point 2. Gradient point 2 should be around the height of the image - but different effects can be achieved by varying it. Likewise, increasing Gradient point 1 from 0 increases the brightness of the first part of the reflection - creating a nice controllable reflection fall-off.

In a cocoa application the reflection gradient parameters could be more usefully mapped to a couple of sliders. If a simpler interface is needed, you could hard wire the ‘recommended’ values into the relevant inputs.

Gap: Makes a gap between the reflection and the image. This improves the illusion that the image is sitting on a surface.

To Do
- with a little effort the patch could be used in a cocoa application or, I think, converted to an image unit for use in other applications.

- thorough testing of how images with alpha channels work.

Key Quartz Composer Techniques
- mask and alpha manipulations.
- blending modes