arCamera View is static lo

Luis_Mb · January 17, 2019, 8:13pm

I have noticed that “the vision” of ArCamera in the projects of Augmented Reality remains static .I will explain it better … When ArCamera focuses on a marker it shows entity on the screen, but if I try to move the Arcamera the marker continues to appear in the same position (I expected the marker to appear in a local position dependent on Arcamera); but the camera can move perfectly but the ArMarkers remain still in their World position, I thought I would fix it by making Armarker the son of arCamera but it did not work either

The 4 graphics above represent the scene and what arCamera can see before and after moving. and the last image represents what I would like to see

will · January 18, 2019, 12:04am

Yes. This is because ARToolkit fires events when a marker is detected, providing the marker’s transformation data with reference to a static camera at the origin:

github.com

playcanvas/playcanvas-ar/blob/master/src/playcanvas-ar.js#L827


this.finalMatrix = new pc.Mat4();


this.lastSeen = -1;


this.app.on('trackinginitialized', function (arController) {
    if (self.pattern) {
        arController.loadMarker(self.pattern.getFileUrl(), function (markerId) {
            self.markerId = markerId;
        });
    }
    arController.addEventListener('getMarker', function (ev) {
        var data = ev.data;
        var type = data.type;
        var marker = data.marker;
        if ((self.pattern && type === artoolkit.PATTERN_MARKER && marker.idPatt === self.markerId) ||
            (!self.pattern && type === artoolkit.BARCODE_MARKER && marker.idMatrix === self.matrixId)) {
            // Set the marker entity position and rotation from ARToolkit
            self.markerMatrix.data.set(data.matrix);
            if (arController.orientation === 'portrait') {
                self.finalMatrix.mul2(self.portraitRot, self.markerMatrix);
            } else {

Sure, you could render the marker at the origin and transform the camera by the inverse of the marker’s transformation matrix. But what happens when you detect a second marker in the frame? Or what happens if you can’t detect any markers?

Luis_Mb · January 18, 2019, 4:58am

Thank you very much @Will ,. I’ll take a little, but I have something in mind to solve it. I’ll post it maybe it’s useful for someone else …