Question

In Processing, I can successfully draw depth maps from 2 Kinects using SimpleOpenNI, but I’m now trying to draw 2 “scenes” (from enableScene() vs enableDepth()). Both Kinects are detected but when I draw the output, I see the same scene is drawn twice (whereas using enableDepth() always gave me 2 different depth images). Any ideas what I’m doing wrong? Thanks in advance.

/* --------------------------------------------------------------------------
 * SimpleOpenNI Multi Camera Test
 * --------------------------------------------------------------------------
 */

import SimpleOpenNI.*;

SimpleOpenNI cam1;
SimpleOpenNI cam2;

void setup()
{
  size(640 * 2 + 10,480); 

  // start OpenNI, loads the library
  SimpleOpenNI.start();

  // init the cameras
  cam1 = new SimpleOpenNI(0,this);
  cam2 = new SimpleOpenNI(1,this);

  // set the camera generators ** HAD TO REVERSE ORDER FOR BOTH KINECTS TO WORK

  // enable Scene
  if(cam2.enableScene() == false)
  {
     println("Can't open the scene for Camera 2"); 
     exit();
     return;
  }

  // enable depthMap generation 
  if(cam1.enableScene() == false)
  {
     println("Can't open the scene for Camera 1"); 
     exit();
     return;
  }

  background(10,200,20);
}

void draw()
{
  // update the cams
  SimpleOpenNI.updateAll();

  image(cam1.sceneImage(),0,0);

  image(cam2.sceneImage(),640 + 10,0);
}

Answer 1

I’ve done another text using the sceneMap() functionality but it looks like there is indeed an issue with SimpleOpenNI not updating properly internally:

/* --------------------------------------------------------------------------
 * SimpleOpenNI Multi Camera Test
 * --------------------------------------------------------------------------
 */

import SimpleOpenNI.*;

SimpleOpenNI cam1;
SimpleOpenNI cam2;

int numPixels = 640*480;
int[] sceneM1 = new int[numPixels];
int[] sceneM2 = new int[numPixels];
PImage scene1,scene2;

void setup()
{
  size(640 * 2 + 10,480 * 2 + 10); 

  // start OpenNI, loads the library
  SimpleOpenNI.start();

  // init the cameras
  cam1 = new SimpleOpenNI(0,this);
  cam2 = new SimpleOpenNI(1,this);

  // set the camera generators ** HAD TO REVERSE ORDER FOR BOTH KINECTS TO WORK

  // enable Scene
  if(cam2.enableScene() == false)
  {
     println("Can't open the scene for Camera 2"); 
     exit();
     return;
  }
//  cam2.enableDepth();//this fails when using only 1 bus

  // enable depthMap generation 
  if(cam1.enableScene() == false)
  {
     println("Can't open the scene for Camera 1"); 
     exit();
     return;
  }
  cam1.enableDepth();

  scene1 = createImage(640,480,RGB);
  scene2 = createImage(640,480,RGB);

  background(10,200,20);
}

void draw()
{
  // update the cams
  SimpleOpenNI.updateAll();

  image(cam1.depthImage(),0,0);
  image(cam1.sceneImage(),0,0);

  cam1.sceneMap(sceneM1);
  cam2.sceneMap(sceneM2);
  updateSceneImage(sceneM1,scene1);
  updateSceneImage(sceneM2,scene2);
  image(scene1,0,490);
  image(scene2,650,490);
}
void updateSceneImage(int[] sceneMap,PImage sceneImage){
  for(int i = 0; i < numPixels; i++) sceneImage.pixels[i] = sceneMap[i] * 255;
  sceneImage.updatePixels();
}

Using something like

cam1.update();
cam2.update();

rather than

SimpleOpenNI.updateAll();

doesn’t change anything.

An issue was filed, hopefully it will be resolved.
In the meantime, try using OpenNI in a different language/framework.
OpenFrameworks has many similarities to Processing (and many differences
as well to be honest, but it’s not rocket science).
Try the experimental ofxOpenNI addon to test multiple cameras, hopefully it will resolve your issue.