Why do all the coordinates from the QueryVertices are zero?

Question

For the following code:

Reads the depth data from the sensor and fills in the matrix
***/
void SR300Camera::fillInZCoords()
{
    Image::ImageData depthImage;
    Image *depthMap = sample->depth;
    depthMap->AcquireAccess(Image::ACCESS_READ, &depthImage);
    Image::ImageInfo imgInfo = depthMap->QueryInfo();
    int depth_stride = depthImage.pitches[0] / sizeof(pxcU16);
    Projection * projection = device->CreateProjection();
    unsigned int wxhDepth = depth_width * depth_height;
    Point3DF32* vertices = new Point3DF32[wxhDepth];
    projection->QueryVertices(depthMap, vertices);
    pxcU16 *dpixels = (pxcU16*)depthImage.planes[0];
    unsigned int dpitch = depthImage.pitches[0] / sizeof(pxcU16); /* aligned width */

    for (int k = 0; k < wxhDepth; k++) {
        cout << "xx is " << vertices[k].x << endl;
        cout << "yy is " << vertices[k].y << endl;
        cout << "zz is " << vertices[k].z << endl;
    }

}

I just get zero for everything printed. It is told in the SDK documentation in order to convert depth image UV-map coordinates in pixels to xyz-map of realworld in mm use QueryVertices. However, for me it just returns 0. I get both colored and depth image and I am not sure what has gone wrong. Here's more info from debugging the code:

*

-       vertices    0x00000261e4934040 {x=0.000000000 y=0.000000000 z=0.000000000 } Intel::RealSense::Point3DF32 *
        wxhDepth    307200  unsigned int
-       depthImage.pitches  0x00000075a2da9de0 {1280, 0, 0, 0}  int[4]
-       planes  0x00000075a2da9df0 {0x00000261e7542000 "", 0x0000000000000000 <NULL>, 0x0000000000000000 <NULL>, 0x0000000000000000 <NULL>} unsigned char *[4]
+       reserved    0x00000075a2da9dd4 {0, 0, 0}    int[3]
        format  PIXEL_FORMAT_DEPTH (131072) Intel::RealSense::Image::PixelFormat

*

Answer 1

Here's the correct answer to get the xyzMap from the Depth image UVmap:

PXCImage::ImageData depthImage;
depthMap->AcquireAccess(PXCImage::ACCESS_READ, &depthImage);
PXCImage::ImageInfo imgInfo = depthMap->QueryInfo();
depth_width = imgInfo.width;
depth_height = imgInfo.height;
num_pixels = depth_width * depth_height;
PXCProjection * projection = device->CreateProjection();
PXCPoint3DF32 *pos3D = new PXCPoint3DF32[num_pixels];
sts = projection->QueryVertices(depthMap, &pos3D[0]);
if (sts < Status::STATUS_NO_ERROR) {
    wprintf_s(L"Projection was unsuccessful! \n");
    sm->Close();
}