Saving point cloud data into a file - processing

Question

I have the following code working on Processing 2, with Kinect:
import org.openkinect.freenect.*;
import org.openkinect.processing.*;
// Kinect Library object
Kinect kinect;
// Angle for rotation
float a = 0;
// We'll use a lookup table so that we don't have to repeat the math over and over
float[] depthLookUp = new float[2048];
void setup() {
// Rendering in P3D
size(1200, 800, P3D);
kinect = new Kinect(this);
kinect.initDepth();
// Lookup table for all possible depth values (0 - 2047)
for (int i = 0; i < depthLookUp.length; i++) {
depthLookUp[i] = rawDepthToMeters(i);
}
}
void draw() {
background(0);
// Get the raw depth as array of integers
int[] depth = kinect.getRawDepth();
// We're just going to calculate and draw every 4th pixel (equivalent of 160x120)
int skip = 4;
// Translate and rotate
translate(width/2, height/2, -50);
rotateY(a);
for (int x = 0; x < kinect.width; x += skip) {
for (int y = 0; y < kinect.height; y += skip) {
int offset = x + y*kinect.width;
// Convert kinect data to world xyz coordinate
int rawDepth = depth[offset];
PVector v = depthToWorld(x, y, rawDepth);
stroke(255);
pushMatrix();
// Scale up by 200
float factor = 200;
translate(v.x*factor, v.y*factor, factor-v.z*factor);
// Draw a point
point(0, 0);
popMatrix();
}
}
// Rotate
a += 0.015f;
}
// These functions come from: http://graphics.stanford.edu/~mdfisher/Kinect.html
float rawDepthToMeters(int depthValue) {
if (depthValue < 2047) {
return (float)(1.0 / ((double)(depthValue) * -0.0030711016 + 3.3309495161));
}
return 0.0f;
}
PVector depthToWorld(int x, int y, int depthValue) {
final double fx_d = 1.0 / 5.9421434211923247e+02;
final double fy_d = 1.0 / 5.9104053696870778e+02;
final double cx_d = 3.3930780975300314e+02;
final double cy_d = 2.4273913761751615e+02;
PVector result = new PVector();
double depth = depthLookUp[depthValue];//rawDepthToMeters(depthValue);
result.x = (float)((x - cx_d) * depth * fx_d);
result.y = (float)((y - cy_d) * depth * fy_d);
result.z = (float)(depth);
return result;
}
I would like to save pointcloud data in a file, so I can import it later on another program, such as Cinema 4D.
how do I create this file?

Answer 1

Processing has several functions for saving data to file, the simplest of which is saveStrings().
To use the saveStrings() function, you would simply store whatever you wanted to save into a String array, and then pass that into the function along with a filename.
You can then use the loadStrings() function to read the data from a file back into a String array.
How you format the data into a String is entirely up to you. You might store it as comma separated values.
More info can be found in the reference.
If you want to store the data into a file that another program can read, you have to first look up exactly what format that file needs to be in. I'd start by opening up some example files in a basic text editor.