/** Some VRPN orientation sensors may be rotated differently than what we
* expect them to be (for example, orientation is correct except that
* the camera is pointing in the wrong direction). This function will
* adjust the orientation matrix so that the camera is pointing in the
* correct direction. */
static void viewmat_fix_rotation(float orient[16])
{
// Fix rotation for a hard-wired orientation sensor.
if(viewmat_control_mode == VIEWMAT_CONTROL_ORIENT)
{
float adjustLeft[16] = { 0, 1, 0, 0,
0, 0, 1, 0,
1, 0, 0, 0,
0, 0, 0, 1 };
mat4f_transpose(adjustLeft); // transpose to column-major order
float adjustRight[16] = { 0, 0, -1, 0,
-1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 0, 1 };
mat4f_transpose(adjustRight);
mat4f_mult_mat4f_new(orient, adjustLeft, orient);
mat4f_mult_mat4f_new(orient, orient, adjustRight);
return;
}
// Fix rotation for VRPN
if(viewmat_vrpn_obj == NULL || strlen(viewmat_vrpn_obj) == 0)
return;
char *hostname = vrpn_default_host();
if(hostname == NULL)
return;
/* Some objects in the IVS lab need to be rotated to match the
* orientation that we expect. Apply the fix here. */
if(vrpn_is_vicon(hostname)) // MTU vicon tracker
{
/* Note, orient has not been transposed/inverted yet. Doing
* orient*offset will effectively effectively be rotating the
* camera---not the world. */
if(strcmp(viewmat_vrpn_obj, "DK2") == 0)
{
float offsetVicon[16];
mat4f_identity(offsetVicon);
mat4f_rotateAxis_new(offsetVicon, 90, 1,0,0);
mat4f_mult_mat4f_new(orient, orient, offsetVicon);
}
if(strcmp(viewmat_vrpn_obj, "DSight") == 0)
{
float offsetVicon1[16];
mat4f_identity(offsetVicon1);
mat4f_rotateAxis_new(offsetVicon1, 90, 1,0,0);
float offsetVicon2[16];
mat4f_identity(offsetVicon2);
mat4f_rotateAxis_new(offsetVicon2, 180, 0,1,0);
// orient = orient * offsetVicon1 * offsetVicon2
mat4f_mult_mat4f_many(orient, orient, offsetVicon1, offsetVicon2, NULL);
}
}
}
/** Uses the VRPN library to get the position and orientation of a
* tracked object.
*
* @param object The name of the object being tracked.
*
* @param hostname The IP address or hostname of the VRPN server or
* tracking system computer. If hostname is set to NULL, the
* ~/.vrpn-server file is consulted.
*
* @param pos An array to be filled in with the position information
* for the tracked object. If we are unable to track the object, a
* message may be printed and pos will be set to a fixed value.
*
* @param orient An array to be filled in with the orientation matrix
* for the tracked object. The orientation matrix is in row-major
* order can be used with OpenGL. If the tracking system is moving an
* object around on the screen, this matrix can be used directly. If
* the tracking system is moving the OpenGL camera, this matrix may
* need to be inverted. If we are unable to track the object, a
* message may be printed and orient will be set to the identity
* matrix.
*
* @return 1 if we returned data from the tracker. 0 if there was
* problems connecting to the tracker.
*/
int vrpn_get(const char *object, const char *hostname, float pos[3], float orient[16])
{
/* Set to default values */
vec3f_set(pos, 10000,10000,10000);
mat4f_identity(orient);
#ifdef MISSING_VRPN
printf("You are missing VRPN support.\n");
return 0;
#else
if(object == NULL || strlen(object) == 0)
{
msg(WARNING, "Empty or NULL object name was passed into this function.\n");
return 0;
}
if(hostname != NULL && strlen(hostname) == 0)
{
msg(WARNING, "Hostname is an empty string.\n");
return 0;
}
/* Construct an object@hostname string. */
std::string hostnamecpp;
std::string objectcpp;
if(hostname == NULL)
{
char *hostnameInFile = vrpn_default_host();
if(hostnameInFile)
hostnamecpp = hostnameInFile;
else
{
msg(ERROR, "Failed to find hostname of VRPN server.\n");
exit(EXIT_FAILURE);
}
}
else
hostnamecpp = hostname;
objectcpp = object;
std::string fullname = objectcpp + "@" + hostnamecpp;
/* Check if we have a tracker object for that string in our map. */
if(nameToTracker.count(fullname))
{
/* If we already have a tracker object, ask it to run the main
* loop (and therefore call our handle_tracker() function if
* there is new data). */
nameToTracker[fullname]->mainloop();
/* If our callback has been called, get the callback object
* and get the data out of it. */
if(nameToCallbackData.count(fullname))
{
vrpn_TRACKERCB t = nameToCallbackData[fullname];
float pos4[4];
for(int i=0; i<3; i++)
pos4[i] = t.pos[i];
pos4[3]=1;
double orientd[16];
// Convert quaternion into orientation matrix.
q_to_ogl_matrix(orientd, t.quat);
for(int i=0; i<16; i++)
orient[i] = (float) orientd[i];
/* VICON in the MTU IVS lab is typically calibrated so that:
* X = points to the right (while facing screen)
* Y = points into the screen
* Z = up
* (left-handed coordinate system)
*
* PPT is typically calibrated so that:
* X = the points to the wall that has two closets at both corners
* Y = up
* Z = points to the door
* (right-handed coordinate system)
*
* By default, OpenGL assumes that:
* X = points to the right (while facing screen in the IVS lab)
* Y = up
* Z = points OUT of the screen (i.e., -Z points into the screen in te IVS lab)
* (right-handed coordinate system)
*
* Below, we convert the position and orientation
* information into the OpenGL convention.
*/
if(strlen(hostnamecpp.c_str()) > 14 && strncmp(hostnamecpp.c_str(), "tcp://141.219.", 14) == 0) // MTU vicon tracker
{
float viconTransform[16] = { 1,0,0,0, // column major order!
0,0,-1,0,
0,1,0,0,
0,0,0,1 };
mat4f_mult_mat4f_new(orient, viconTransform, orient);
mat4f_mult_vec4f_new(pos4, viconTransform, pos4);
vec3f_copy(pos,pos4);
return 1; // we successfully collected some data
}
else // Non-Vicon tracker
{
/* Don't transform other tracking systems */
// orient is already filled in
vec3f_copy(pos, pos4);
return 1; // we successfully collected some data
}
}
}
else
{
/* If this is our first time, create a tracker for the object@hostname string, register the callback handler. */
msg(INFO, "Connecting to VRPN server: %s\n", hostnamecpp.c_str());
// If we are making a TCP connection and the server isn't up, the following function call may hang for a long time
vrpn_Connection *connection = vrpn_get_connection_by_name(hostnamecpp.c_str());
/* Wait for a bit to see if we can connect. Sometimes we don't immediately connect! */
for(int i=0; i<1000 && !connection->connected(); i++)
{
usleep(1000); // 1000 microseconds * 1000 = up to 1 second of waiting.
connection->mainloop();
}
/* If connection failed, exit. */
if(!connection->connected())
{
delete connection;
msg(ERROR, "Failed to connect to tracker: %s\n", fullname.c_str());
return 0;
}
vrpn_Tracker_Remote *tkr = new vrpn_Tracker_Remote(fullname.c_str(), connection);
nameToTracker[fullname] = tkr;
tkr->register_change_handler((void*) fullname.c_str(), handle_tracker);
kuhl_getfps_init(&fps_state);
kalman_initialize(&kalman, 0.1, 0.1);
}
return 0;
#endif
}
