I should add I am holding the phone horizontally (as you would when taking a photo).
As such I modify the sensor values like: SensorManager.getRotationMatrix(R, I, accels, mags); SensorManager.remapCoordinateSystem(R,SensorManager.AXIS_X, SensorManager.AXIS_Z, outR); SensorManager.getOrientation(outR, values); I'm assuming thats the correct way to do it. On Aug 20, 6:00 pm, mscwd01 <[email protected]> wrote: > The main problem is when I use the values returned by the sensor > manager "as is" i.e. not modifying them in any way, the points are no > where near where they should be. For example, say the point I wish to > project is due north of my current location and at the same elevation. > I shouldn't need to tilt (pitch) the phone up or down and when I hold > the phone in the direction of north it should appear somewhere near > the center of the phone screen. However, this is not the case, in > reality for the point to appear on the center of the screen I need to > do something like tilt the phone at the ground and orient it in a > easterly direction for example. > > I have made a nasty fix which means I subtract 90 from the roll or add > 45 degrees to the pitch etc. However while this now projects the point > on the center of the screen it ruins the projections of any other > points (as I have fundamentally altered the sensor values). In my > current implementation a point north of me may work but any points to > the south do not work. > > My problem is probably something to do with the coordinates of the > phone differing from my projected coordinates, but making the two > "work" together is causing me some serious headaches. > > I can send you my projection code if it helps, I have really exhausted > all ideas to solve my issue! > > Thanks for the reply > > On Aug 20, 5:15 pm, Peli <[email protected]> wrote: > > > > however, I can never seem to get accurate screen coordinates > > > of the points. > > > Could you specify what exactly your problem is? > > Does it not work *at all*, or does it work basically, but points are > > off by a few degrees? Or does it only work in one orientation of the > > device (like in landscape mode), and fails in other orientations? > > > Peliwww.openintents.orghttp://code.google.com/p/openintents/wiki/SensorSi... > > > On Aug 20, 4:55 pm, mscwd01 <[email protected]> wrote: > > > > Hi, > > > > I want to find the screen coordinates (X,Y) where a point represented > > > by a latitude/longitude value would appear on the screen if you > > > pointed your phone at it (much in the same way as Wikitude does). > > > > Here is my code from my onSensorChanged() method: > > > > public void onSensorChanged(SensorEvent event) { > > > Sensor sensor = event.sensor; > > > int type = sensor.getType(); > > > > switch (type) { > > > case Sensor.TYPE_MAGNETIC_FIELD: > > > mags = event.values.clone(); > > > isReady = true; > > > break; > > > case Sensor.TYPE_ACCELEROMETER: > > > accels = event.values.clone(); > > > break; > > > case Sensor.TYPE_ORIENTATION: > > > orients = event.values.clone(); > > > break; > > > } > > > > if (mags != null && accels != null && isReady) { > > > isReady = false; > > > > SensorManager.getRotationMatrix(R, I, accels, mags); > > > SensorManager.remapCoordinateSystem(R, > > > SensorManager.AXIS_X, SensorManager.AXIS_Z, outR); > > > SensorManager.getOrientation(outR, values); > > > > azimuth = convert.radToDeg(values[0]); > > > pitch= convert.radToDeg(values[1]); > > > roll = convert.radToDeg(values[2]); > > > > } > > > > } > > > > I convert the points I wish to project from their lat/lon spherical > > > coordinates to Cartesian coordinates and perform a perspective > > > projection using the roll, pitch and azimuth values returned by the > > > sensor, however, I can never seem to get accurate screen coordinates > > > of the points. > > > > The matrices for roll, pitch and azimuth I use are: > > > > // pan > > > double[][] azimuthMat = { > > > {Math.cos(azimuthValue), -Math.sin(azimuthValue), 0}, > > > {Math.sin(azimuthValue), Math.cos(azimuthValue), 0}, > > > {0, 0, 1},}; > > > > // tilt > > > double[][] pitchMat = { > > > {Math.cos(pitchValue), 0, Math.sin(pitchValue)}, > > > {0, 1, 0}, > > > {-Math.sin(pitchValue), 0, Math.cos(pitchValue)}, > > > }; > > > // roll > > > double[][] rollMat = { > > > {1, 0, 0}, > > > {0, Math.cos(rollValue), -Math.sin(rollValue)}, > > > {0, Math.sin(rollValue), Math.cos(rollValue)}, > > > }; > > > > I also perform the necessary translation of the projection cener and > > > the point to project e.g: > > > > // Translate the point > > > subtract(pointToProject, projectionCenter); > > > ... where 'pointToProject' and 'projectionCenter' are double arrays > > > holding the Cartesian coordinates of each location (i.e. camera lat/ > > > lon and the point to project lat/lon) > > > > I realise this is quite a complicated question to ask and I haven't > > > provided all my projection code etc, however if someone feels they can > > > help me out and may know how to achieve what i'm after - i'll post the > > > whole code. > > > > Thanks --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. 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