GRAIN noir weblog

Started working on new visuals for GRAIN noir a/v live set.
I wanted to setup a simple communication between Ableton and openFrameworks via OSC to trigger visual effects according to sound variation.

I already did something similar before with Processing using MIDI data only but this time I wanted a more detailed system with specific frequency range affecting corresponding visuals in real time.

Each track in Ableton got a Max for Live Analysis Grabber loaded to that send both trigger and follower data for low, mids and high frequencies to openFrameworks on a specific port defined in the master GrabberSender.

In order to map the sound data to openFrameworks parameters the follower message is checked and updated using ofxOscMessage:

introTrack.cpp

void introTrack::findOSC(OSC &osc) {
    while(osc.receiver.hasWaitingMessages()){
        // get the next message
        ofxOscMessage m;
        osc.receiver.getNextMessage(&m);
        
        // check for follower message
        if(m.getAddress() == "/introKickFollower"){
        introKickFollower = m.getArgAsFloat(0);
        }
    }
}

After checking the data type of the received trigger message it’s now possible to pass the sound follower data into oF parameters:

introTrack.cpp

void introTrack::oscTrigger()   {
    for(int i = 0; i < NUM_MSG_STRINGS; i++){
        ofDrawBitmapString(msg_strings[i], 10, 40 + 15 * i);
        if(msg_strings[i] == "/introKickTrigger: int32:1"){
            // map sound data when trigger message is received
            ofBackground(255, 255, 255);
            ofSetColor(0,0,0);
            ofCircle(ofGetWidth()/2, ofGetHeight()/2, introKickFollower);           
        }
    }
}

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A/V live OSC test

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