# Camera - View matrix in Android + openGLES 2

I am trying to use the touch screen on the tablet to control my camera movements and generate the view matrix accordingly.

I get the x and y coordinates of the screen and after doing some sanity checks on it I use them. My problem is I get the image and based on the movement it moves - but the object is always at a offset from the touch/pointer position. And I am not able to understand why. ( Kind of new at it)

Here is the camera logic - Where pX and pY are coordinates of the device screen.

pitch = pY * 0.05;
yaw =   pX * 0.05;

LOGD(">>pitch %f", pY);

pitch = min(pitch,90.0f);
pitch = max(pitch,-90.0f);

LOGD(">>pitch(alter) %f", pitch);

if(yaw < 0) {
yaw += 360.0f;
}
if(yaw > 360.0f) {
yaw -= 360.0f;
}


I am not sure whether I am going about it in the right direction. Any suggestions will be appreciated.

• what is "the object"? the object you try to rotate or the given coordinates? – ScrambledRK Feb 19 '13 at 10:42
• Its the object in the world. Right now I have a triangle. – Amit Ahire Feb 19 '13 at 12:02
• maybe the coordinates you compare are not in the same space. maybe the swipe coordinates are in screenspace/cameraspace but the object coordinates are in worldspace. I don't really know how you could transform them into the same space though. – ScrambledRK Feb 19 '13 at 15:59