Dronetronics VJ Set, Taipei.

Here is a pic from my first VJ outing, for Dronetronics, in Taipei, back in December. IMG_0340_4-cropped Lars from Dronetronics got in contact 2 hours before the gig, to see if I had anything for a gig at a studio not far away.   I quickly repurposed my smilies test vis (see previous post) to be suitable for Drone Music.
  • Removing the smilies
  • Added functionality to change the graphic when a button was pressed
  • Removed the OSC control - due to how sensitive the APC Mini sliders were, it looked quite amateurish (as they pick up every jolt as you move).
  • Put in new graphics (here, I only had time to find some black and white ideograms of a skull and a 'warning') sign plus an "X" I drew in the two minutes before the gig.
  • Added an option for graphics to wrap around (in the taxi on the way to the gig).
In the end, it was a great learning experience VJing for the first time, from the tech through to the setup. With thanks to Dronetronics and the studio crew at UUMouth Studio.   Sourcecode for the vis will go up shortly.

Year Of Code

I spent a year on my own projects (+ travelling).   The focus was on creative coding and the tech around it, from learning about bezier curves and opengl, through to OSC and MIDI. Here are some of the things I was lucky enough to work on.

Modern OpenGL, OpenGLES and WebGL

I tried to devour every opengl, webgl and opengl es tutorial I could find.    The open source drivers turn out to be very strict, which found a number of bugs in tutorials, which I was later able to fix... Staring at a blank screen gives you a real appreciation for how good we have it in higher level tutorials. It was a real eye-opener how to see how much opengl has changed recently, which makes for a steep learning curve.


Python Creative Coding Environment

Shoebot recieved many patches, including support for livecoding, porting to Gtk 3 and lots of work to make it easier to install. In the runup to Libre Graphics Meeting 2016 we are continuing to consolidate this work.

VJing for Dronetronics in Taipei

Putting everything together, VJ'd for local Drone band "Dronetronics". The first vis was built with only 2 hours notice (!) so repurposed the Smilies vis, into something more appropriate for the dronetronics sound. The second vis was built in nodebox-gl and made heavy use of the image filters and effects it provides.

Progress: end-to-end music vis working

Initial versions of all the parts of my music vis / VJ tool are now in place: The midi controller connected to a python program, which sends OSC to the separate music vis (still the smilies). Now, I need to go back and rebuild/polish some of the more prototypey bits of the code so they can uploaded. Unfortunately the USB socket died on my physical midi controller, so controlling with a (prototype) emulator I built in this video. I've learned a lot more about the linux graphics stack than I ever wanted to, once these are polished it'll finally be time to make some different visuals.

PSA – Use ‘SNA’ if you are on optimus

"Optimus" is the tech where your laptop has an Intel AND an Nvidia card, the amount of problems this can cause are more than the sum of the parts on Linux. Trying to run apps on the Nvidia card had all sorts of issues until I switched the intel card on 'SNA' ("the successor to UXA"). It seems like every few years intel changes how their graphics cards work, and the new hotness is SNA. Before this, glitches included black windows, and apps just freezing until I resized their windows, or if you ran more than one GL app. As per the answer here at https://ask.fedoraproject.org/en/question/32960/black-windows-in-gnome-3-suddenly add the following to your /etc/X11/xorg.conf
Section "Device"
 Identifier "Intel Graphics"
 Driver "intel"
 Option "AccelMethod" "sna"
I'm not sure it's entirely problem free, I have had one or two logouts, but at least I can run more than one instance of my own app without random freezing and glitching.   [EDIT] It turns out I'm still getting glitchyness and lockups running on intel, at least running things on the Nvidia card with DRI_PRIME=1 works though. [/EDIT]  

Android NDK Notes

Some notes on NDK problems I've had to overcome in the last few days, there are bound to be corrections needed, I'll try and update these based on any comments.

Environment variables

Various scripts use different ones to discover the location of the NDK - so don't be surprised when you see ANDROID_NDK, ANDROID_NDK_ROOT, ANDROID_NDK_HOME, or anything else - they mean the same thing, right now I'm using ANDROID_NDK currently.


There are lots of different versions of android_cmake, subtly incompatible, you probably will need to edit scripts. Before trying to use cmake with Android, make sure you can build some apps using the standard tools, or the scripts that come with them This is something I'll probably come back to, as I'm using gradle and Android.mk right now.

Android Studio

In transition

Android used to use Eclipse and ANT, now it's in transition to Android Studio and Gradle, hence some things don't work, but they can be tweaked - this situation will probably change.

Installing NDK

Has it's own copy of the NDK, you can install it from the preferences in the Android SDK section, if you already installed a copy it won't automatically find it.

Build works when launching from terminal, but not using desktop icon

Android Studio doesn't pick up variables set in '.bashrc' - this means scripts may work if you launch it from a terminal, but not from the desktop.

Taking ages opening project, message about gradle

Android studio downloads this the first time, if you want more information load it from the terminal and you will see some info as it downloads.

Error about "JCenter" when trying to build

This can be because you have a really old version of gradle installed (ie the one that comes with Ubuntu 15.04) - if on Ubuntu you can test this by building using the "gradlew" script in your project, if this works then upgrade gradle - on Ubuntu there is a gradle PPA.

Not picking up settings in local.properties

You can add this at the top of your app.gradle
Properties properties = new Properties()
def sdkDir = properties.getProperty('sdk.dir')
def ndkDir = properties.getProperty('ndk.dir')
Then add ndkDir to your ndkBuild section
// call regular ndk-build(.cmd) script from app directory
task ndkBuild(type: Exec) {
    if (Os.isFamily(Os.FAMILY_WINDOWS)) {
        commandLine ndkDir + '/ndk-build.cmd', '-C', file('src/main').absolutePath
    } else {
        commandLine ndkDir + '/ndk-build', '-C', file('src/main').absolutePath


Including other Android.mk files

You can do this like this
include $(LOCAL_PATH)/../assimp/workspaces/Android-NDK/jni/Android.mk
Make sure to do these includes at the end of your own file  as they may overwrite variables like LOCAL_PATH, also $(call my-dir) returns the name of the latest included file. http://grokbase.com/t/gg/android-ndk/128zkazrb1/unable-to-generate-multiple-so-files-for-native-libraries-using-a-single-make-file   http://stackoverflow.com/a/4650113/62709

No rule to make target

The build couldn't find the mentioned file, if you use a variable like LOCAL_PATH, maybe it was overwritten - see the section on includes

Outputting values from Android.mk

$(info hi, LOCAL_PATH is $(LOCAL_PATH))
$(warning Uh oh...)
$(error this is the error message that will stop the build process)

Running on a real device

cannot locate symbol “srand”

Android 21 changed the location of some symbols - either set your minimum sdk to 21 and build with that, or have a lower one (e.g. 19) and build with that SDK http://discuss.cocos2d-x.org/t/android-debug-mode-works-but-release-dont-crashes-at-launch/20247/5

Everything else

Expect to do a lot of googling, expect to have to change makefiles. ... look at other projects using the libraries you use and see how they work, good luck !