Bounding box of models and center of rotation of the camera in xtk

Question

Trying out http://www.goxtk.com, great stuff! Is there a quick way to get the bounding box for a model or some other point that could be used as the center of rotation of the camera? Worst case, what's the best way to loop over the points? Thanks for any replies!

Answer 1

It is possible to query each X.object() for its centroid, like this:

...
r = new X.renderer('r');
r.init();

o = new X.object();
o.load('test.vtk');

r.add(o);
r.render();

r.onShowtime = function() {

    // print the centroid
    console.log(o.points().centroid());

};
...

You have to overload the onShowtime function of the X.renderer to be sure that the X.object was properly setup (.vtk file loaded etc.).

To configure the camera, you can do f.e. the following:

...
r.camera().setPosition(-400,0,0); // set the position
r.camera().setFocus(-10,-10,-10); // set the focus point
r.camera().setUp(1,0,0); // set the (normalized) up vector
r.render();
...

Anyway, to loop over the points:

...
// o is an X.object
var numberOfPoints = o.points().count();
var pointArrayLength = o.points().length(); // equals numberOfPoints * 3
var allPoints = o.points().all(); // as a flat 1D array optimized for WebGL

// just loop it :)
...