I wondering if someone could give me a hand with this problem I'm having with objects and collisions in Unity.
I have a sphere object being controlled by the users phone's accelerometer. The sphere moves around fine but once it hits a wall the sphere starts acting weird. It pulls in the direction of the wall it collided with, starts bouncing, and just overall not responsive anymore to the movement of the phone.
Any idea as to why this could be happening?
Here is the script used to control the player's sphere.
using UnityEngine;
using System.Collections;
public class PlayerController : MonoBehaviour {
public float speed;
void Update() {
Vector3 dir = Vector3.zero;
dir.x = Input.acceleration.x;
dir.z = Input.acceleration.y;
if (dir.sqrMagnitude > 1)
dir.Normalize();
dir *= Time.deltaTime;
transform.Translate(dir * speed);
}
void OnTriggerEnter (Collider other)
{
if (other.gameObject.tag == "Pickup") {
other.gameObject.SetActive(false);
}
}
}
That happens because your object has a 'Rigidbody' component, and, I suppose, it's not a kinetic rigidbody. Basically, it behaves just like it should: a real physical object will not pass through another object, that is the most basic behaviour of a physics engine. However, since you don't operate with the physics-based object using forces, but manually change it's position, you break a level of abstraction. In result, you move the object inside the wall, and now it can't get out.
Use ApplyForce method instead. If you want to pull or push object (instead of just move, which contradicts the fact that these objects are managed by physics) in a certain direction every frame, you should use ForceMode.Acceleration (or ForceMode.Force, if you want the effect to depend on the mass) every physics frame, which means that you have to use FixedUpdate method instead of Update.
Related
I know, there is always a lot of questions about this error BUT I didn't succeed to fix it with the previous answers...
So, please, let me explain.
I'm working with the Hololens tech. Recently, I have updated from HoloToolKit to MRTK V2 (new SDK provided by Microsoft and the community). My app worked with HoloToolKit, Unity and 2017.4. I updated for MRTKv2 and 2019.2 (recommended).
I have some scripts that use the camera position. In my previous app, Camera was BiCamera (GameObject), child of Basic (GameObject). And my BiCamera was tagged as MainCamera. Right now, my camera was Main Camera (with a space between the 2 words), tagged MainCamera, child of MixedRealityPlayspace. This camera is provided by the MRTKv2. I can't change the settings.
So, when I'm in a Play mode I have this message in yellow :
The referenced script on this Behaviour (Game Object 'Main Camera') is missing!
And when I move my Main Camera in order to simulate a walk of the user (Hololens = augmented reality), I have this message in red :
NullReferenceException: Object reference not set to an instance of an object
TextSpeedUI.Update () (at Assets/Scripts/TextSpeedUI.cs:23)
I think the second message is linked to the first... My script TextSpeedUI needs the camera.transform to calculate walking speed (in fact not directly, he finds the public variable from another GameObject, but this GameObject requires Camera.transform).
An other option is linked with the GameObject Main Camera provided by MRTK because when I select this GameObject I have a missing script. A message says that I have to fix compile errors... But perhaps it's a consequence not the origin... I'm lost.
TextSpeedUI.cs 23
if (sd.isActiveAndEnabled && sd.Steps.Count > 4)
{
xzSpeed = (sd.Steps[sd.Steps.Count - 1].localMinPosition - sd.Steps[sd.Steps.Count - 4].localMinPosition) / ((sd.Steps[sd.Steps.Count - 1].t - sd.Steps[sd.Steps.Count - 4].t));
txt.text = (xzSpeed.magnitude * 3.6).ToString("0.##"); // speed in km/h
}
sd comes from public StepDetector sd; which is at the beginning of my script TextSpeedUI.cs
And my script StepDetector.cs calls public DataManager dm;
In my DataManager.cs script, I call at the beginning :
public Camera Cam { get; private set; }
And in void Start :
Cam = Camera.main;
Thanks a lot
I've solved by myself (just remove the component). It seems that it doesn't have consequence on my scene...
I'm setting a new project which is intended to deploy to both HoloLens 1 and 2, and I'd like to use hand rays in both, or at least be able to simulate them on HoloLens 1 in preparation for HoloLens 2.
As far as I have got is:
Customizing the InputSimulationService to be gesture only (so I can test in editor)
Adding the GGVHand Controller Type to DefaultControllerPointer Options in the MRTK/Pointers section.
This gets it to show up and respond to clicks both in editor and device, but it does not use the hand coordinates and instead raycasts forward from 0,0,0, which suggests that the GGV Hand Controller is providing a GripPosition (of course with no rotation due to HL1) but not providing a Pointer Pose.
I imagine the cleanest way to do this would be to add a pointer pose to the GGV Hand controller, or add (estimated) rotation to the GripPosition and use this as the Pose Action in the ShellHandRayPointer. I can't immediately see where to customize/insert this in the MRTK.
Alternatively, I could customize the DefaultControllerPointer prefab but I am hesitant to do so as the MRTK seems to still be undergoing frequent changes and this would likely lead to upgrade headaches.
You could create a custom pointer that would set the pointer's rotation to be inferred based on the hand position, and then like you suggested use Grip Pose instead of Pointer Pose for the Pose Action.
The code of your custom pointer would look something like this:
// Note you could extend ShellHandRayPointer if you wanted the beam bending,
// however configuring that pointer requires careful setup of asset.
public class HL1HandRay : LinePointer
{
public override Quaternion Rotation
{
get
{
// Set rotation to be line from head to head, rotated a bit
float sign = Controller.ControllerHandedness == Handedness.Right ? -1f : 1f;
return Quaternion.Euler(0, sign * 35, 0) * Quaternion.LookRotation(Position - CameraCache.Main.transform.position, Vector3.up);
}
}
// We cannot use the base IsInteractionEnabled
// Because HL1 hands are always set to have their "IsInPointing pose" field as false
// You may want to do more thorough checks here, following BaseControllerPointer implementation
public override bool IsInteractionEnabled => IsFocusLocked || IsTracked;
}
Then create a new pointer prefab and configure your pointer profile to use the new pointer prefab. Creating your own prefab instead of modifying MRTK prefabs has advantage of ensuring that MRTK updates will not overwrite your prefabs.
Here's some captures of the simple pointer prefab I made to test this with relevant changes highlighted:
And then the components I used:
I am starting to learn Unity.
As I understand, We can write scripts(behaviors) in the form of C# files and apply them to each objects on the scene.
But how to write a script for the entire scene? I know this is a obvious question - there has to be a script for the entire scene so that all my objects "behave" in a synchronized way and it's gotta be pretty basic, but preliminary Google searches has not borne much fruit.
Can someone give me a quick guide?
Taking your "boxes" example comment I would do the following:
Create an empty gameobject, let's call it BoxesController...
Attach below BoxesController.cs script to it
In the editor inspector reference all boxes
BoxesController.cs
public class BoxesController: MonoBehaviour
{
public Transform box1, box2, box3;
void Update() {
// change boxes position
}
}
Now imagine you will need to have > 30 boxes in current scene... You will have a lot of work to reference each box. So you could change your script if you add a Tag to all boxes. Let's say you create a new tag inside Unity Tag Manager called "Box" and give it to all boxes.
You now can change BoxesController.cs script to the above and you will not have to reference all boxes in the Editor Inspector because they will be searched and referenced inside Start method.
BoxesController.cs
public class BoxesController: MonoBehaviour
{
public GameObject[] boxes;
void Start()
{
boxes = GameObject.FindGameObjectsWithTag("Box");
}
void Update() {
// change boxes position
foreach (GameObject go in boxes)
{
//get box name
string box_name = go.Name;
// get box transform property
Transform t = go.transform;
}
}
}
Please note that GameObject.FindGameObjectsWithTag is a heavy operation and that's why I did it in the Start method and saved the result to reuse it in Update method calls.
what you can do is create an empty GameObject and add a script to it and use one of the techniques described in the link to get access to the 3 boxes you want to move.
http://docs.unity3d.com/412/Documentation/ScriptReference/index.Accessing_Other_Game_Objects.html
In this case you probably want to use "1. Through inspector assignable references." which just means create a public Transform variable in the script, save, then in the Inspector drag the box in the slot that appeared in the script-component
edit: for further reading i'd suggest googling the term "Game Manager" in combination with "Singelton" and "Unity" :)
From my few years of experience programming in graphics, one thing that I have learned is that you should never pass in a reference to a graphics context to an object and operate on it for the duration of the program (JOGL explicitly states this). A context can be invalidated when something such as the graphics device (GPU) is reset, turned off, or some other weird thing happens.
I have recently delved back into programming in XNA 4.0, and one of my projects involves objects needing to know about the size of the window/viewport, when the window is resized, and when dynamic buffers have lost their content (requiring the buffers to be rebuilt on a possibly invalidated GraphicsDevice). Instead of passing in the GraphicsDevice and GameWindow to numerous methods in the update phase or for Disposal, I have opted to pass them into constructors. For example:
public Camera(GameWindow w, GraphicsDeviceManager m) {
// ... Yada-yada matrices
gdm = m;
window = w;
window.ClientSizeChanged += OnWindowResize;
}
public void Dispose() {
window.ClientSizeChanged -= OnWindowResize;
window = null;
gdm = null;
}
// Control Logic ...
public void OnWindowResize(object Sender, EventArgs args) {
Vector2 s = new Vector2(gdm.GraphicsDevice.Viewport.TitleSafeArea.Width, gdm.GraphicsDevice.Viewport.TitleSafeArea.Height);
// Recalculate Projection ...
}
Is it safe to do something like this, or is something happening in the background that I need to be aware of?
I solved this problem in my current game project by running the game as a singleton, which makes it available in a static context within the namespace. Game.Instance.graphicsDevice will always point to the current graphics device object, even if the context has changed. XNA raises various events when the context is invalidated/changed/reset/etc., and you can reload/re-render things and resize buffers as needed by hooking in to these events.
Alternatively, you could pass GraphicsDevice with the ref keyword, which might be a quick, drop-in fix by simply being the same reference as the original caller, assuming that caller that instantiated your objects either has the original reference object or had the GraphicsDevice passed to it with ref as well.
I'm writing a mobile phone game using j2me. In this game, I am using multiple Canvas objects.
For example, the game menu is a Canvas object, and the actual game is a Canvas object too.
I've noticed that, on some devices, when I switch from one Canvas to another, e.g from the main menu to the game, the screen momentarily "flickers". I'm using my own double buffered Canvas.
Is there anyway to avoid this?
I would say, that using multiple canvases is generally bad design. On some phones it will even crash. The best way would really be using one canvas with tracking state of the application. And then in paint method you would have
protected void paint(final Graphics g) {
if(menu) {
paintMenu(g);
} else if (game) {
paintGame(g);
}
}
There are better ways to handle application state with screen objects, that would make the design cleaner, but I think you got the idea :)
/JaanusSiim
Do you use double buffering? If the device itself does not support double buffering you should define a off screen buffer (Image) and paint to it first and then paint the end result to the real screen. Do this for each of your canvases. Here is an example:
public class MyScreen extends Canvas {
private Image osb;
private Graphics osg;
//...
public MyScreen()
{
// if device is not double buffered
// use image as a offscreen buffer
if (!isDoubleBuffered())
{
osb = Image.createImage(screenWidth, screenHeight);
osg = osb.getGraphics();
osg.setFont(defaultFont);
}
}
protected void paint(Graphics graphics)
{
if (!isDoubleBuffered())
{
// do your painting on off screen buffer first
renderWorld(osg);
// once done paint it at image on the real screen
graphics.drawImage(osb, 0, 0, Tools.GRAPHICS_TOP_LEFT);
}
else
{
osg = graphics;
renderWorld(graphics);
}
}
}
A possible fix is by synchronising the switch using Display.callSerially(). The flicker is probably caused by the app attempting to draw to the screen while the switch of the Canvas is still ongoing. callSerially() is supposed to wait for the repaint to finish before attempting to call run() again.
But all this is entirely dependent on the phone since many devices do not implement callSerially(), never mind follow the implementation listed in the official documentation. The only devices I've known to work correctly with callSerially() were Siemens phones.
Another possible attempt would be to put a Thread.sleep() of something huge like 1000 ms, making sure that you've called your setCurrent() method beforehand. This way, the device might manage to make the change before the displayable attempts to draw.
The most likely problem is that it is a device issue and the guaranteed fix to the flicker is simple - use one Canvas. Probably not what you wanted to hear though. :)
It might be a good idea to use GameCanvas class if you are writing a game. It is much better for such purpose and when used properly it should solve your problem.
Hypothetically, using 1 canvas with a sate machine code for your application is a good idea. However the only device I have to test applications on (MOTO v3) crashes at resources loading time just because there's too much code/to be loaded in 1 GameCanvas ( haven't tried with Canvas ). It's as painful as it is real and atm I haven't found a solution to the problem.
If you're lucky to have a good number of devices to test on, it is worth having both approaches implemented and pretty much make versions of your game for each device.