Kinect SDK 2: CoordinateMapper not returning valid results -

i understand calling mapping function should simple on debugging following code colorspacepoint values -1.#inf0000. cameraspacepoint pass mapping method fine. have ideas why case? thanks.

    _sensor = kinectsensor::getdefault()      //do stuff      cameraspacepoint pos3d = body->joints->lookup(t->jointtype()).position; // works.     colorspacepoint pos = _sensor->coordinatemapper->mapcamerapointtocolorspace(pos3d); 

from comments of coordinatemapperbasics sample project:

//the sentinel value -inf, -inf, meaning no depth pixel corresponds color pixel.

so valid value color pixels corresponding depth pixel, should perform check make sure value isn't negative infinity.