I'm writing program about Kinect skeleton track program.While the Definition of the gesture is written in the program. I want the definition of gesture to be defined by the user.One way of doing this is by DFA. I don't konw how to start with C#. Can any one help?
Try using Lists to store the coordinates of the skeleton's joints (kind of a buffer) and then you could maybe run a DFA. you could define your transitions as a range of coordinates for every direction , and the final state would be when the elements in the buffer are approximativily in the same area.
So in C# you will need to create a datatype to save the sequece of the gesture that will get updated when the user adds one.Lists for buffers as I stated below.
When saving the gesture your code will look like :
While(!Joint_stable && (i < buffer.count() ) )
{
While ((buffer.Joint.ElementAt(i+1).X-buffer.Joint.ElementAt(i)).X>0 && (buffer.Joint.ElementAt(i+1)-buffer.Joint.ElementAt(i).Y )>0 ) //Think about adding tolerence here
{
Gesture.add("Upper_Right");
}
...
}
Just an advice , the kinect sensor is not that accurate so try to establish a kind of tolerance.
I Hope that my answer will help you or at least give you some inspiration :)
Related
in this video, https://youtu.be/klBvssJE5Qg I shows you how to spawn enemies outside of a fixed camera. (this is in GDscript by the way) How could I make this work with a moving camera? I wanna make a zombie fighting game with a moving camera and zombies spawning outside that.
I would really appreciate help with this.
I've tried researching on the internet about how to do it, but I just didn't find it.
N/A..................................
After looking at the video, I see they are using this line to spawn:
Global.instance_node(enemy_1, enemy_position, self)
This suggest to me a couple thing:
The position is probably either relative to the self passed as argument or global.
There must be an Autoload called Global that I need to check to make sure.
And the answer is in another castle video.
In the video Godot Wave Shooter Tutorial #2 - Player Shooting we find this code:
extends Node
func instance_node(node, location, parent):
var node_isntance = node.instance()
parent.add_child(node_instance)
node_instance.global_position = location
return node_instance
And thus, we are working with global coordinates global_position. Thus enemy_position is used as global coordinates.
Ok, instead of using enemy_position as global coordinates we are going to use it as local coordinates of the Camera2D (or a child of it). Which means you need a reference to the Camera2D (which I don't know where do you have it).
You could make your code in a child of the Camera2D, or take the transform of the Camera2D using a RemoteTransform2D. Either way, you could then work in its local coordinates. Thus you would do this:
Global.instance_node(enemy_1, to_global(enemy_position), self)
Or you could have a reference by exporting a NodePath (or in the newest Godot you can export a Camera2D) from your script and set it via the inspector. So you can do this:
Global.instance_node(enemy_1, camera.to_global(enemy_position), self)
Where camera is your reference to the Camera2D.
In the following section of Arena.gd:
func _on_Enemy_spawn_timer_timeout():
var enemy_position = Vector2(rand_range(-160, 670), rand_range(-90, 390))
I believe you can add the X and Y coordinates of the camera to their corresponding random ranges in the enemy position Vector2. This will displace the enemy depending on where the camera is currently located.
You can get the position of the camera with this:
get_parent().get_node("Name of your camera").position
When this is all put together:
func _on_Enemy_spawn_timer_timeout():
var enemy_position = Vector2(rand_range(-160, 670) + get_parent().get_node("Name of your camera").position.x, rand_range(-90, 390) + get_parent().get_node("Name of your camera").position.y)
Keep in mind that you might need to displace the values in the following while loop as well. I hope this helps.
I'm currently working on animating my player so that he behaves like he's breathing.
if(time mod 60==0){
if(image_index==0){
image_index=1;
}
else{
image_index=0;
}
}
time++;
The whole thing is put in the step event and sprite is changing every single step and it even changes to an index 2 and 3, which I haven't even used in the code.
So if anyone has some ideas why does it work like this then please tell me.
It is because the sprite you use has multiple sub-images. GameMaker will naturally iterate the image index every frame.
So first, you need to stop the animation from running with
image_speed = 0;
You have to run this line when the sprite has just been changed, so ideally just after the "sprite_index" variable is changed. If you don't change it, just set image_speed to zero in the creation code.
If you are curious, I found the answer here : How to freeze sprite animation on last frame?
I am working on a pool game of sorts. To create a table, I have used cubes as sides. I want to use the inbuilt physics engine to get those sides interact with the balls. Sadly I am unable to get it working.
Here is what I have done. I created cube as side, and a sphere for ball. To move the sphere, I am using rigidbody.MovePosition function. both the cube and sphere have colliders and rigidbody attached, and gravity turned off.
Sphere movement is fine, but when it collides with cube, it makes the cube fly. Since the cube is supposed to be an immovable wall, I constrained all axes rotation and movement. But, using constraints cause physics engine to go bonkers. Instead of sphere coming to stop or moving in opposite direction, it simply passes through the cube. Clearly, something is wrong, and I need help figuring out the same.
Thanks in advance.
Here is the code used to move the sphere.
public float movePower = 10.0f;
// Update is called once per frame
void Update ()
{
if(Input.GetKey(KeyCode.LeftArrow))
{
rigidbody.MovePosition(transform.position + Vector3.left* movePower * Time.deltaTime);
}
if(Input.GetKey(KeyCode.RightArrow))
{
rigidbody.MovePosition(transform.position + Vector3.right* movePower * Time.deltaTime);
}
if(Input.GetKey(KeyCode.DownArrow))
{
rigidbody.MovePosition(transform.position + Vector3.down* movePower * Time.deltaTime);
}
if(Input.GetKey(KeyCode.UpArrow))
{
rigidbody.MovePosition(transform.position + Vector3.up* movePower * Time.deltaTime);
}
}
The simplest way is to remove the Rigidbody from all cubes as they are supposed to be fixed. Another way is to mark the cubes' Rigidbody components as Kinematic, but this meant to be used for moving objects like player characters that should participate in physics but should not be moved by the engine.
I recommend reading the Unity Physics man page.
Update:
More things to consider:
Don't check Is Trigger
Check that your Layer Collision Matrix is set up right (menu Edit/Project Settings/Physics)
If the velocity is pretty high, physics engine might get confused and collision are not detected
Ensure that the models are not scaled down or up extremely (best is to have scale = 1)
The best mass for Rigidbody.mass is 1
Be careful when playing with PhysicsManager settings like Min Penetration For Penalty or Solver Iteration Count
Use gravity if possible
Never move by manipulating Transform directly. Use Rigidbody methods instead
Avoid calling rigidbody.MovePosition on every update if it's a constant linear motion. Do it once and leave it untouched
Remember to use FixedUpdate for calling rigidbody.MovePosition etc.
For example, there are QR scanners which scan video stream in real time and get QR codes info.
I would like to check the light source from the video, if it is on or off, it is quite powerful so it is no problem.
I will probably take a video stream as input, maybe make images of it and analyze images or stream in real time for presence of light source (maybe number of pixels of certain color on the image?)
How do I approach this problem? Maybe there is some source of library?
It sounds like you are asking for information about several discreet steps. There are a multitude of ways to do each of them and if you get stuck on any individual step it would be a good idea to post a question about it individually.
1: Get video Frame
Like chaitanya.varanasi said, AVFoundation Framework is the best way of getting access to an video frame on IOS. If you want something less flexible and quicker try looking at open CV's video capture. The goal of this step is to get access to a pixel buffer from the camera. If you have trouble with this, ask about it specifically.
2: Put pixel buffer into OpenCV
This part is really easy. If you get it from openCV's video capture you are already done. If you get it from an AVFoundation you will need to put it into openCV like this
//Buffer is of type CVImageBufferRef, which is what AVFoundation should be giving you
//I assume it is BGRA or RGBA formatted, if it isn't, change CV_8UC4 to the appropriate format
CVPixelBufferLockBaseAddress( Buffer, 0 );
int bufferWidth = CVPixelBufferGetWidth(Buffer);
int bufferHeight = CVPixelBufferGetHeight(Buffer);
unsigned char *pixel = (unsigned char *)CVPixelBufferGetBaseAddress(Buffer);
cv::Mat image = cv::Mat(bufferHeight,bufferWidth,CV_8UC4,pixel); //put buffer in open cv, no memory copied
//Process image Here
//End processing
CVPixelBufferUnlockBaseAddress( pixelBuffer, 0 );
note I am assuming you plan to do this in OpenCV since you used its tag. Also I assume you can get the OpenCV framework to link to your project. If that is an issue, ask a specific question about it.
3: Process Image
This part is by far the most open ended. All you have said about your problem is that you are trying to detect a strong light source. One very quick and easy way of doing that would be to detect the mean pixel value in a greyscale image. If you get the image in colour you can convert with cvtColor. Then just call Avg on it to get the mean value. Hopefully you can tell if the light is on by how that value fluctuates.
chaitanya.varanasi suggested another option, you should check it out too.
openCV is a very large library that can do a wide wide variety of things. Without knowing more about your problem I don't know what else to tell you.
Look at the AVFoundation Framework from Apple.
Hope it helps!
You can try this method: start by getting all images to an AVCaptureVideoDataOutput. From the method:captureOutput:didOutputSampleBuffer:fromConnection,you can sample/calculate every pixel. Source: answer
Also, you can take a look at this SO question where they check if a pixel is black. If its such a powerful light source, you can take the inverse of the pixel and then determine using a set threshold for black.
The above sample code only provides access to the pixel values stored in the buffer; you cannot run any other commands but those that change those values on a pixel-by-pixel basis:
for ( uint32_t y = 0; y < height; y++ )
{
for ( uint32_t x = 0; x < width; x++ )
{
bgraImage.at<cv::Vec<uint8_t,4> >(y,x)[1] = 0;
}
}
This—to use your example—will not work with the code you provided:
cv::Mat bgraImage = cv::Mat( (int)height, (int)extendedWidth, CV_8UC4, base );
cv::Mat grey = bgraImage.clone();
cv::cvtColor(grey, grey, 44);
I'm having trouble with physics in unity 3d. I'm wanting my ball to bounce off of walls and go another direction. When the ball hits the wall it just bounces straight back. I have tried changing the direction to be orthogonal to the direction it hits the wall but it doesn't change direction. Due to this, the ball just keeps hitting the wall and bouncing straight back.
Secondly, sometimes the ball goes through the wall. The walls have box colliders while the ball has a sphere collider. They all have continuous dynamic as the collision detection mode.
Here's a link to a similar thread:
http://forum.unity3d.com/threads/22063-I-shot-an-arrow-up-in-the-air...?highlight=shooting+arrow
Personally, I would code the rotation using LookAt as GargarathSunman suggests in this link, but if you want to do it with physics, you'll probably need to build the javelin in at least a couple of parts, as the others suggest in the link, and add different drag and angular drag values to each part,perhaps density as well. If you threw a javelin in a vacuum, it would never land point down because air drag plays such an important part (all things fall at the same rate regardless of mass, thank you Sir Isaac Newton). It's a difficult simulation for the physics engine to get right.
Maybe try to get the collider point between your sphere and your wall then catch your rigidbody velocity and revert it by the collision point normal.
an example of a script to do that ---> (put this script on a wall with collider )
C# script:
public class WallBumper : MonoBehaviour
{
private Vector3 _revertDirection;
public int speedReflectionVector = 2;
/***********************************************
* name : OnCollisionEnter
* return type : void
* Make every gameObject with a RigidBody bounce againt this platform
* ********************************************/
void OnCollisionEnter(Collision e)
{
ContactPoint cp = e.contacts[0];
_revertDirection = Vector3.Reflect(e.rigidbody.velocity, cp.normal * -1);
e.rigidbody.velocity = (_revertDirection.normalized * speedReflectionVector);
}
}
I recently has an issue with a rocket going through targets due to speed and even with continuous dynamic collision detection I couldn't keep this from happening a lot.
I solved this using a script "DontGoThroughThings" posted in wiki.unity3d.com. This uses raycasting between current and previous positions and then ensures the frame ends with the colliders connected for messages an OnTrigger event. Has worked everytime since and it's just a matter of attaching the script so super easy to use.
I think the physics answer is as others have suggested to use multiple components with different drag although typically I think you only want a single RigidBody on the parent. Instead of direction using transform.LookAt you could try and calculate using Quaternion.LookRotation from the rigidbody.velocity. Then use Vector3.Angle to find out how much are are off. The greater the angle diference the more force should be experienced and then use RigidBody.ApplyTorque. Maybe use the Sin(angleDifference) * a constant so less force is applied to torque as you approach proper rotation.
Here is some code I used on my rocket although you'll have to substitute some things as I was pointing toward a fixed target and you'll want to use your velocity.
var rotationDirection = Quaternion.LookRotation(lockedTarget.transform.position - this.transform.position);
var anglesToGo = Vector3.Angle(this.transform.rotation.eulerAngles, rotationDirection.eulerAngles);
if (anglesToGo > RotationVelocity)
{
var rotationDirectionToMake = (rotationDirection * Quaternion.Inverse(this.transform.rotation)).eulerAngles.normalized * RotationVelocity;
transform.Rotate(rotationDirectionToMake);
}