ARObject.getCenter() only returns 0

[GoogleCodeExporter]

Hey guys,

The ARObject class provides a public method called getCenter(). If it returns 
the coordinate of the detected marker center, that would be exactly what I 
want. But it returns nothing but all 0.0. Anyone has an idea about this? 

What version of the product are you using? On what operating system?
I am using the newest code from SVN, my phone is HTC Desire.

Thanks a lot in advance.

best,
Cecilia

Original issue reported on code.google.com by cecilia...@gmail.com on 20 May 2011 at 1:20

[GoogleCodeExporter]

I also tried to get the marker coordinate from the matrix which we can get from 
getTransMat() in ARObject class. The returned matrix has a changing value but 
the values in the most right column does not reflect the correct marker 
position. it only ranges in somewhere around the upper left corner of the 
screen.

Original comment by cecilia...@gmail.com on 20 May 2011 at 3:51

[GoogleCodeExporter]

Yeah can please someone tell how to get Marker Co-Ordinates. In the arUTIl.c 
file there is a comment that it is included in some current matrix.How Can I 
get as I need to calculate where is the marker position on the screen.

Original comment by mohammad...@gmail.com on 15 Jul 2011 at 2:21

[GoogleCodeExporter]

hey guys,

did u all find anything, regarding the x,y position of marker related to screen.

plz let me know 

- shashank

Original comment by shashank...@gmail.com on 23 Aug 2011 at 6:27

[GoogleCodeExporter]

Hi everyone,I just solve the problem,if you guys want to get the rawX and rawY 
in screen,you can use the function gluProject,because opengl default sets the 
original point(0,0,0) in the center of the marker,so we can use the function by 
following method: 
gl.gluProject(0f, 0f, 0f,glMatrix, 0,glCameraMatrix, 0,viewport, 
0,windowCoords, 0);
And then windowCoords will contain the raw value.

PS:I have test the values by using the OnTouch event getRawX() and getRawY(), 
and the vaule is the same.

If you guys have any problem,please mail to me,I'm glad to help you guys!

Original comment by hijam...@gmail.com on 25 Feb 2012 at 11:29

[GoogleCodeExporter]

Someone managed to make it work?

I've tried using all the methods proposed but not working

Original comment by diou.ber...@gmail.com on 26 Mar 2013 at 2:47

[GoogleCodeExporter]

I solved this issue thanks to clues received from Diou.
We have to create a class eg Projector:

    package edu.dhbw.andar.sample;
    import javax.microedition.khronos.opengles.GL10;
    import javax.microedition.khronos.opengles.GL11;
    import android.graphics.Point;
    import android.opengl.GLU;

    public class Projector {
        int[] viewport = new int[4];
        float[] modelview = new float[16];
        float[] projection = new float[16];
        float[] vector = new float[4];

        public void setViewport(GL10 gl) {
            gl.glGetIntegerv(GL11.GL_VIEWPORT, viewport, 0);
        }

        public synchronized Point getScreenCoords(double[] transMat, GL10 gl) {
            GL11 gl11 = (GL11) gl;

            gl11.glGetFloatv(GL11.GL_MODELVIEW_MATRIX, modelview, 0);
            gl11.glGetFloatv(GL11.GL_PROJECTION_MATRIX, projection, 0);

            GLU.gluProject((float) transMat[0], (float) transMat[1],(float) transMat[1], modelview, 0, projection, 0, viewport, 0, vector, 0);

            Point p = new Point((int) vector[0], (int) (viewport[3] - vector[1]));
            return p;
        }
    }

Then in class CustomObject:

    Projector projector = new Projector();

In method public final void draw(GL10 gl)

    projector.setViewport(gl);
    Point xy = projector.getScreenCoords(getTransMatrix(), gl);

And xy are our screen coordinates.

Original comment by tzonk1...@gmail.com on 4 Dec 2013 at 12:12