With my team we want to implement area learning for relocalization purposes in our projects.
I added this functionnality and it seems to work well. But when a drift disaster happens (motion tracking lost) and that the main camera is instantaneously projected in "the other side of the universe" the program doesn't succeed in relocalizing it : the camera is 2 meters below, or 3 meters beside than where it should be.
Is it an area description error (because it has got not enough point of interests) ?
Or I still have not understood how to use area learning ?
Thanks a lot.
P.S.:
I use the Unity SDK.
public void Update()
{
TangoPoseData pose = new TangoPoseData ();
TangoCoordinateFramePair pair;
if(poseLocalized)
{
pair.baseFrame = TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_AREA_DESCRIPTION;
pair.targetFrame = TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_DEVICE;
}
else
{
pair.baseFrame = TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_START_OF_SERVICE;
pair.targetFrame = TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_DEVICE;
}
double timestamp = VideoOverlayProvider.RenderLatestFrame(TangoEnums.TangoCameraId.TANGO_CAMERA_COLOR);
PoseProvider.GetPoseAtTime (pose, timestamp, pair);
m_status = pose.status_code;
if (pose.status_code == TangoEnums.TangoPoseStatusType.TANGO_POSE_VALID)
{
// it does not differ with the pair base frame
Matrix4x4 ssTd = UpdateTransform(pose);
m_uwTuc = m_uwTss * ssTd * m_dTuc;
}
}
public void OnTangoPoseAvailable(TangoPoseData pose)
{
if (pose == null)
{
return;
}
// Relocalization signal
if (pose.framePair.baseFrame == TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_AREA_DESCRIPTION &&
pose.framePair.targetFrame == TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_START_OF_SERVICE)
{
poseLocalized = true;
}
// If pose status is not valid, nothing is valid
if (!(pose.status_code == TangoEnums.TangoPoseStatusType.TANGO_POSE_VALID))
{
poseLocalized = false;
// Do I forget something here ?
}
}
I've regularly observed that the localization and re-localization of the Area Learning can produce x,y Pose coordinates off by a few meters.
Coordinates can be more accurate if I take more care in recording an area well before moving to a new area.
Upon re-localization the coordinate accuracy is improved if the tablet is able to observe the area using slow, consistent movements before traveling to a new area.
If I learn a new area I always return to a well known area for better accuracy as described by drift correction:
I have two Tango tablets using a Java app that is autonomously navigating an iRobot in my home. I've setup a grid test site using 1 meter tape marks to make the observations.
Related
I can't make the jump work in my game made in game maker studio 2
this project uses gravity and the game maker's language.
this is now just random words so stack overflow lets me post this question so Minecraft is a cool game :).
here is the code:
/// #description this is the create event
// You can write your code in this editor
sprite_index=Sprite1;
image_speed = 1;
image_index = 0;
step event:
/// #description Insert description here
// You can write your code in this editor
#region //gravedad
if place_free(x,y+1){
gravity =1;
}else{
gravity=0;
}
if vspeed >=20{vspeed=20}
#endregion
#region //movimiento
if keyboard_check(ord("D")){
direction=0
speed = brr;
}
else{
speed=0;
}
if keyboard_check(ord("A")){
direction=180
speed = brr;
}
if keyboard_check_pressed(vk_space) && !place_free(x,y+1){
vspeed = -broo;
}
#endregion
I think the !place_free(x,y+1) is the problem here
if keyboard_check_pressed(vk_space) && !place_free(x,y+1){
vspeed = -broo;
}
Assuming place_free checks if there's no collision, it may either be a case of setting the origin point of the player object to the bottom center, or not having a solid instance or collision mask. (as seen in the manual)
I personally prefer using place_meeting to check on collisions with a specific object, and ignore the requirements needed for place_free to work, maybe that could work better for you.
I'm quite new to Processing.
I'm trying to make Processing randomly play a video after I clear the screen by mouseclick, so I create an array that contain 3 videos and play one at a time.
Holding 'Spacebar' will play a video and release it will stop the video. Mouseclick will clear the screen to an image. The question is how can it randomize to another video if I press spacebar again after clear the screen.
I've been searching all over the internet but couldn't find any solution for my coding or if my logic is wrong, please help me.
Here's my code.
int value = 0;
PImage photo;
import processing.video.*;
int n = 3; //number of videos
float vidN = random(0, n+1);
int x = int (vidN);
Movie[] video = new Movie[3];
//int rand = 0;
int index = 0;
void setup() {
size(800, 500);
frameRate(30);
video = new Movie[3];
video[0] = new Movie (this, "01.mp4");
video[1] = new Movie (this, "02.mp4");
video[2] = new Movie (this, "03.mp4");
photo = loadImage("1.jpg");
}
void draw() {
}
void movieEvent(Movie video) {
video.read();
}
void keyPressed() {
if (key == ' ') {
image(video[x], 0, 0);
video[x].play();
}
}
void mouseClicked() {
if (value == 0) {
video[x].jump(0);
video[x].stop();
background(0);
image(photo, 0, 0);
}
}
You have this bit of logic in your code which picks a random integer:
float vidN = random(0, n+1);
int x = int (vidN);
In theory, if you want to randomise to another video when the spacebar is pressed again you can re-use this bit of logic:
void keyPressed() {
if (key == ' ') {
x = int(random(n+1));
image(video[x], 0, 0);
video[x].play();
}
}
(Above I've used shorthand of the two lines declaring vidN and x, but the logic is the same. If the logic is harder to follow since two operations on the same line (picking a random float between 0,n+1 and rounding down to an integer value), feel free to expand back to two lines: readability is more important).
As side notes, these bit of logic look a bit off:
the if (value == 0) condition will always be true since value never changes, making both value and the condition redundant. (Perhaps you plan to use for something else later ? If so, you could save separate sketches, but start with the simplest version and exclude anything you don't need, otherwise, in general, remove any bit of code you don't need. It will be easier to read, follow and change.)
Currently your logic says that whenever you click current video resets to the start and stops playing and when you hit the spacebar. Once you add the logic to randomise the video that the most recent frame of the current video (just randomised) will display (image(video[x], 0, 0);), then that video will play. Unless you click to stop the current video, previously started videos (via play()) will play in the background (e.g. if they have audio you'll hear them in the background even if you only see one static frame from the last time space was pressed).
Maybe this is the behaviour you want ? You've explained a localised section of what you want to achieve, but not overall what the whole of the program you posted should do. That would help others provide suggestions regarding logic.
In general, try to break the problem down to simple steps that you can test in isolation. Once you've found a solid solution for each part, you can add each part into a main sketch one at a time, testing each time you add something. (This way if something goes wrong it's easy to isolate/fix).
Kevin Workman's How To Program is a great article on this.
As a mental excercise it will help to read through the code line by line and imagine what it might do. Then run it and see if the code behaves as you predicted/intended. Slowly and surely this will get better and better. Have fun learning!
I decided I wanted to learn how to work with the unity2D engine, and started with trying to make pong. This was going pretty good, until I found a problem I couldn't find/didn't understand an answer for on google .
Every time the player/AI hits the ball, I make the ball go a little bit faster. This works fine until the ball goes pretty fast (still playable though) and just passes through the player/AI. I solved this by making the box collider of the player/AI really long, but at really high (and unplayable) speeds it still goes through.
My solution works, but isn't that pretty, and I wonder if there is a better solution for this (make the engine check more often for collisions?).
Here's the script for the ball movement (Javascript):
#pragma strict
var StartSpeed : int;
var speedFactor : float;
function Start () {
yield WaitForSeconds(2);
StartBall();
}
function ResetBall () {
GetComponent.<Rigidbody2D>().velocity.x = 0;
GetComponent.<Rigidbody2D>().velocity.y = 0;
transform.position.x = 0;
transform.position.y = 0;
yield WaitForSeconds(0.5);
StartBall();
}
function StartBall () {
var randomDirection = Random.Range(0f,1f);
var randomAngle = Random.Range(-Mathf.PI/4, Mathf.PI/4);
if(randomDirection < 0.5f){
GetComponent.<Rigidbody2D>().velocity.x = Mathf.Cos(randomAngle) * StartSpeed;
GetComponent.<Rigidbody2D>().velocity.y = Mathf.Sin(randomAngle) * StartSpeed;
}else{
GetComponent.<Rigidbody2D>().velocity.x = - Mathf.Cos(randomAngle) * StartSpeed;
GetComponent.<Rigidbody2D>().velocity.y = Mathf.Sin(randomAngle) * StartSpeed;
}
}
function OnCollisionEnter2D (colInfo : Collision2D) {
if(colInfo.collider.tag == "Player"){
GetComponent.<Rigidbody2D>().velocity.x = speedFactor * GetComponent.<Rigidbody2D>().velocity.x;
if(colInfo.collider.GetComponent.<Rigidbody2D>().velocity.y == 0){
GetComponent.<Rigidbody2D>().velocity.y = speedFactor * GetComponent.<Rigidbody2D>().velocity.y;
}
var vel = GetComponent.<Rigidbody2D>().velocity;
Debug.Log("Speed: " + vel);
}
}
Any other comments on the script that may improve it are welcome!
EDIT: I tried the following (as Andrew suggested):
function OnCollisionEnter2D (colInfo : Collision2D) {
if(colInfo.collider.tag == "Player"){
GetComponent.<Rigidbody2D>().AddForce( Vector2 (speedFactor * GetComponent.<Rigidbody2D>().velocity.x, speedFactor * GetComponent.<Rigidbody2D>().velocity.y));
var vel = GetComponent.<Rigidbody2D>().velocity;
Debug.Log("Speed: " + vel);
}
}
This still causes the problem I had before.
Update your RigidBody settings and set Collision Detection to Continuous (it will probably be set to discrete) and your high speed collision will work fine.
You shouldn't be messing with the velocity directly, try just using AddForce() instead.
Whole physics including collision detection runs on FixedUpdate, so to actually detect any collision colliders must collide when FixedUpdate is called. Let's say one collider isn't moving (wall for example) and another is going right at it, on current call of FixedUpdate collider that is moving is just before the wall, while on the next call of FixedUpdate collider that is moving has passed the wall, because that is it's position step per frame. Visually we see that colliders did collide, but they didn't collide on any call to FixedUpdate. Now, there are two solutions to this, lower the speed or lower the timestep of FixedUpdate ( http://docs.unity3d.com/Manual/class-TimeManager.html ), but this can be bad for framerate, it all depends what machines are you targeting and how hardware hungry your game is.
There is also this open source script which you should look at :
http://wiki.unity3d.com/index.php?title=DontGoThroughThings#C.23_-_DontGoThroughThings.js
I am new to game development but familiar with programming languages. I have started using Flixel and have a working Breakout game with score and lives.
I am just stuck on how I can create a new screen/game over screen if a player runs out of lives. I would like the process to be like following:
Check IF lives are equal to 0
Pause the game and display a new screen (probably transparent) that says 'Game Over'
When a user clicks or hits ENTER restart the level
Here is the function I currently have to update the lives:
private function loseLive(_ball:FlxObject, _bottomWall:FlxObject):void
{
// check for game over
if (lives_count == 0)
{
}
else
{
FlxG:lives_count -= 1;
lives.text = 'Lives: ' + lives_count.toString()
}
}
Here is my main game.as:
package
{
import org.flixel.*;
public class Game extends FlxGame
{
private const resolution:FlxPoint = new FlxPoint(640, 480);
private const zoom:uint = 2;
private const fps:uint = 60;
public function Game()
{
super(resolution.x / zoom, resolution.y / zoom, PlayState, zoom);
FlxG.flashFramerate = fps;
}
}
}
There are multiple ways to go about doing this...
You could use different FlxStates, like I described in the answer to your other post: Creating user UI using Flixel, although you'll have to get smart with passing the score or whatever around, or use a Registry-type setup
If you want it to actually work like you described above, with a transparent-overlay screen, you can try something like this (keep in mind, the exact details may differ for your project, I'm just trying to give you an idea):
First, make sure you have good logic for starting a level, lets say it's a function called StartLevel.
You'll want to define a flag - just a Boolean - that tracks whether or not the game is still going on or not: private var _isGameOver:Boolean; At the very end of StartLevel(), set this to false.
In your create() function for your PlayState, build a new FlxGroup which has all the things you want on your Game Over screen - some text, an image, and something that says "Press ENTER to Restart" (or whatever). Then set it to visible = false. The code for that might look something like:
grpGameOver = new FlxGroup();
grpGameOver.add(new FlxSprite(10,10).makeGraphic(FlxG.Width-20,FlxG.Height-20,0x66000000)); // just a semi-transparent black box to cover your game screen.
grpGameOver.add(new FlxText(...)); // whatever you want to add to the group...
grpGameOver.visible = false;
add(grpGameOver); // add the group to your State.
Depending on how your game is setup, you may also want to set the objects in your group's scrollFactor to 0 - if your game screen scrolls at all:
grpGameOver.setAll("scrollFactor", new FlxPoint(0,0));
In your update() function, you'll need to split it into 2 parts: one for when the game is over, and one for if the game is still going on:
if (_isGameOver)
{
if (FlxG.keys.justReleased("ENTER"))
{
grpGameOver.visible = false;
StartLevel();
}
}
else
{
... the rest of your game logic that you already have ...
}
super.update();
Keep in mind, if you have things that respond to user input anywhere else - like a player object or something, you might need to change their update() functions to check for that flag as well.
Then, the last thing you need to do is in your loseLive() logic:
if (lives_count == 0)
{
_isGameOver = true;
grpGameOver.visible = true;
}
else
...
That should do it!
I would highly recommend spending some time with different tutorials and sample projects to kind of get a better feel for Flixel in general. Photon Storm has some great material to play with (even though he's jumped over to HTML5 games)
I also want to note that if you get comfortable with the way Flixel handles updates, you can get really smart with your state's update() function and have it only call update on the grpGameOver objects, instead of having to change all your other objects updates individually. Pretty advanced stuff, but can be worth it to learn it.
I have a few questions about Geolocator and property DesiredAccuracy.
I have the method GetMyPosition:
public async Task<Geoposition> GetMyPosition()
{
Geoposition myGeoposition = null;
Geolocator myGeolocator = new Geolocator();
myGeolocator.DesiredAccuracy = PositionAccuracy.High;
try
{
myGeoposition = await myGeolocator.GetGeopositionAsync();
return myGeoposition;
}
catch (Exception ex)
{
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
MessageBox.Show("Can't get the position");
});
return null;
}
}
1) Why
Geolocator.DesiredAccuracy = PositionAccuracy.High;
Geolocator.GetGeopositionAsync();
always return Geoposition.Coordinate.PositionSource = Cellular with accuracy 400 - 1600 m (on device Nokia Lumia 520)?
2) Under what settings I can get a high accuracy (50 - 100 m) and PositionSource = Satellite?
3) If I have the loaded maps on my device and I activated the airplane mode on the device, then code
Geolocator myGeolocator = new Geolocator();
myGeolocator.DesiredAccuracy = PositionAccuracy.High;
try
{
myGeoposition = await myGeolocator.GetGeopositionAsync();
return myGeoposition;
}
will work? Without a celluar, only a satellite?
4) How strong is the precision of coordinates depends on the device?
Thanks in advance!
Taken from MSDN
Although the Location Service uses multiple sources of location information, and any of the sources may not be available at any given time (for example, no GPS satellites or cell phone towers may be accessible), the native code layer handles the work of evaluating the available data and choosing the best set of sources. All your application needs to do is to choose between high accuracy or the default, power-optimized setting. You can set this value when you initialize the main Location Service class, GeoCoordinateWatcher.
C#
GeoCoordinateWatcher watcher = new GeoCoordinateWatcher(GeoPositionAccuracy.Default);
So it seems like you can't control which source is used but rather the available source will be used based on the specified position accuracy on GeoCoordinateWatcher. Try initializing a GeoCoordinateWatcher with high accuracy and see what happens
var geoWatcher = new GeoCoordinateWatcher(GeoPositionAccuracy.High);
You can use
Geolocator myGeolocator = new Geolocator();
myGeolocator.DesiredAccuracyInMeters = 20;
...
to explicitly state how accurate you want the location to be which would allow the device to manage its power a little better but whether you get close to that accuracy with your result depends on the quality of the location the device can get. If you're inside a building for example you're not going to get something that accurate without connecting to WIFI