I make a game in Unity3D (+2D ToolKit) for iOS.
It is 2d runner/platformer with side view. So on screen is moving background and obstacles. And we control up/down the main character to overcome obstacles.
The problem is that the moving picture has a visual lag. In other words, it moves jerkily or creates the tail area of the previous frames on iOS-devices. In XCode the number of frames is 30 and over.
I have objects 'plain' with the following script:
public class Move: Monobehavior
{
private float x;
public float Speed = 128.0f;
void Start()
{
x = transform.position.x;
}
void Update()
{
x += Time.DeltaTime *Speed;
Vector3 N = transform.position;
N.x = mathf.FloorInt(x);
transform.position = N;
}
}
The question is how to make the move of background smoother, without jerks and flicker on screen while playing? Maybe the problem is in framerate parameter.
Can anybody help me to find a solution?
I'd say it's the use of the FloorInt function which will move the background only in steps of 1 which is rather not smooth. It should get better when you comment that line out. Do you have any special reason why you are doing the FloorInt there?
The use of floor will definitely hurt your performance. Not only is it one more thing to calculate, but it is actually removing fidelity by removing decimals. This will definalty make the movement look 'jerky'. Also, update is not always called on the same time inteval, depending on what else is happening during that frame, so using Time.delaTime is highly recommended. Another thing, you do not need to set variables for x and Vector3 N, when you can update the transoms position like the code below. And if you have to, you sill only need to create one variable to update, and set your position to it. The code below just updates the players x position at a given rate, based on the amount of time that has passes since the last update. There should be no 'jerky' movement. (Unless you have a serious framerate drop);
public class Move: Monobehavior
{
public float Speed = 128.0f;
void Update()
{
transform.position =
(transform.position.x + (speed*Time.DeltaTime),
transform.position.y,
transform.position.z);
}
}
Related
I wrote a script that writes Input.mousePosition into a file on every frame. The idea is that I want to identify which button on screen the player is trying to click before actually clicking, from the speed of the mouse basically. However, I ran into data like this:
(1113.0, 835.0, 0.0)
(1113.0, 835.0, 0.0)
(1113.0, 835.0, 0.0)
(1126.0, 835.0, 0.0)
Basically on one frame the x position is one value, a couple of frames later it's changed, but in the middle there is no gradation. While my mouse movement was continuous, if I'm to believe Unity, in the example above I hovered on 1 pixel for 3 frames then jumped 13 pixels to the right in one frame. Why is this? Is there any code to get the actual frame by frame position of the mouse?
EDIT:
Vector2 _lastPosition;
StreamWriter _mouseData;
// Start is called before the first frame update
void Start()
{
_mouseData = new StreamWriter(File.Open("sdata.txt", FileMode.Create));
}
// Update is called once per frame
void FixedUpdate()
{
_mouseData.WriteLine(Input.mousePosition.ToString());
if (Input.GetMouseButtonDown(0))
{
_mouseData.WriteLine("CLICK\n\n");
}
_lastPosition = Input.mousePosition;
}
void OnDestroy()
{
_mouseData.Close();
}
EDIT 2:
I changed the code to the following:
void FixedUpdate()
{
_mouseData.WriteLine(Vector2.SqrMagnitude(new Vector2(Input.GetAxis("Mouse X"), Input.GetAxis("Mouse Y"))));
if (Input.GetMouseButtonDown(0))
{
_mouseData.WriteLine("CLICK\n\n");
}
}
Now I'm still getting output that's 50% 0-es and non-0 values are sprinkled in on every second row. Exceptions: a few rows where actual values are supposed to be still contain random 0-es. Now, I'm not super concerned about getting less frequent than 1/frame data, but there's no way to distinguish between these false 0-es and actual 0-es when the mouse is not moving, which is an issue.
I cannot find out from your question but I am guessing that you use the FixedUpdate() method which is unreliable in this situation. Update() is advised to use for calls that you want to execute once per frame.
EDIT:
Also, note that it is recommended that you set your application's framerate to a realistic number since it is unlimited by default (on desktop) and your app could be running with so many FPS that it is faster than how often you can sample your mouse input.
You can set the framerate using: Application.targetFrameRate = 60;
Aside from this problem it is generally a good idea to set your framerate to save yourself some headaches. (This is specifically true if you develop for mobile platforms and test on your desktop.)
I made a car controller in unity to drive around. I've read FixedUpdate is better to use for physical objects instead of Update, but when I switch to Fixed update my car no longer drives. Does anyone know why this might be? Thank so much you for any help you an provide!
public float speed;
public float turnSpeed;
private RigidBody rb;
void Start()
{
rb = GetComponent<Rigidbody>();
}
// Update is called once per frame
void FixedUpdate()
{
Move();
Turn();
}
void Move(){
// moves the car
if (Input.GetKey(KeyCode.W)){
rb.AddRelativeForce(new Vector3(Vector3.forward.x, 0, Vector3.forward.z) * speed);
}
else if (Input.GetKey(KeyCode.S)){
rb.AddRelativeForce(new Vector3(Vector3.forward.x, 0, Vector3.forward.z) * -speed);
}
// maintains forward velocity relative to car.
Vector3 localVelocity = transform.InverseTransformDirection(rb.velocity);
localVelocity.x = 0;
rb.velocity = transform.TransformDirection(localVelocity);
}
void Turn(){
// turns the car.
if (Input.GetKey(KeyCode.D)){
rb.AddRelativeTorque(Vector3.up * turnSpeed);
Debug.Log("TURNING CAR");
}
else if (Input.GetKey(KeyCode.A)){
rb.AddRelativeTorque(-Vector3.up * turnSpeed);
Debug.Log("TURNING CAR");
}
Here's the code. Pressing W or S adds a force, pressing A or D adds a torque. When I try turning in FixedUpdate the console will write "TURNING CAR" as it should which shows that it's making past the AddRelativeTorque line, but it still won't turn so I'm not really sure what's going on. Thanks again, I really appreciate any help.
Try increasing the force used.
Fixed update runs less frequently than update (using the default settings, in most scenarios). Since the code is running much less frequently, less force is being accumulated over the same time period.
Consider a game running at 100fps. The default fixed time step is 0.02s (50 frames per second). Since update is running at 100fps, you have twice as much force being applied from update than would be applied from fixed update.
If you make your force value independent of the time since the last update happened, you will not need to worry about this.
For Update use myForceValue * Time.deltaTime.
For FixedUpdate use myForceValue * Time.fixedDeltaTime.
I want to make sure that various objects moving at high speed cannot pass through walls or other objects. My thought process was to check via Raycast if a collision has occurred between two moments of movement.
So the script should remember the previous position and check via Raycast for collisions between previous and current position.
If a collision has occurred, the object should be positioned at the meeting point and moved slightly in the direction of the previous position.
My problem is that works outside the map not inside. If I go from inside to outside, I can go through the walls. From outside to inside not.
Obviously I have misunderstood something regarding the application with raycasts.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class ObsticalControll : MonoBehaviour
{
private Vector3 positionBefore;
public LayerMask collisionLayer = 9;
private Vector3 lastHit = new Vector3(0, 0, -20);
// Start is called before the first frame update
void Start()
{
positionBefore = transform.position;
}
private void OnDrawGizmos()
{
Gizmos.DrawCube(lastHit, new Vector3(.2f,.2f,.2f));
}
// Update is called once per frame
void Update()
{
Vector3 curruentMovement = transform.position;
Vector2 dVector = (Vector2)transform.position - (Vector2)positionBefore;
float distance = Vector2.Distance((Vector2)positionBefore, (Vector2)curruentMovement);
RaycastHit2D[] hits = Physics2D.RaycastAll((Vector2)positionBefore, dVector, distance, collisionLayer);
if(hits.Length > 0)
{
Debug.Log(hits.Length);
for (int i = hits.Length -1 ; i >= 0 ; i--)
{
RaycastHit2D hit = hits[i];
if (hit.collider != null)
{
Debug.Log("hit");
lastHit.x = hit.point.x;
lastHit.y = hit.point.y;
Vector3 resetPos = new Vector3(hit.point.x, hit.point.y, transform.position.z) + positionBefore.normalized * 0.1f;
transform.position = new Vector3(resetPos.x, resetPos.y, transform.position.z);
}
}
}
positionBefore = transform.position;
}
}
Theres a better way to deal with this that unity has built in.
Assuming the object thats moving at a high speed has a RigidBody(2d in your case) you can set its Collision Detection to Continuous instead of Discrete.
This will help collisions with high speed collision, assuming that its moving at high speed and the wall is not moving.
If for some reason you cannot apply this to your scenario, Ill try to help with the raycast solution.
However, I am still wondering about the collision behavior of my raycast script. That would be surely interesting, if you want to calculate shots or similar via raycast
Alright, so your initial idea was to check if a collision had occurred, By checking its current position and its previous position. And checking if anything is between them, that means a collision has occurred. And you would teleport it back to where it was suppose to have hit.
A better way todo this would be to check where the GameObject would be in the next frame, by raycasting ahead of it, by the distance that it will travel. If it does hit something that means that within the next frame, it would have collided with it. So you could stop it at the collision hit point, and get what it has hit. (This means you wouldn't have to teleport it back, So there wouldn't be a frame where it goes through then goes back)
Almost the same idea but slightly less complicated.
Problem would be that if another object were to appear between them within the next frame aswell, it could not account for that. Which is where the rigidbody.movePosition shines, And with OnCollisionEnter you can detect when and what it collided with correctly. Aswell as without the need to teleport it back
updated CODE .. the problem is that i cant move the ball only if i hold the E button than i use WASD or arrows to move the ball...and when i hold Q the camera 2 activates and i can move the ball with WASD or arrows...but with the right axis for that angle...is like ballance that game... i want to not hold the E or Q just to change the camera and move the ball corecctly for that angle with the right axis for the ball but not holding the cameras button
using UnityEngine;
using System.Collections;
public class controlPlayer : MonoBehaviour {
public float viteza ; // this is speed
;
void Start(){
}
void Update()
{
if(Input.GetKey(KeyCode.Q) ) // if i hold Q the camera 2 activates and with WASD i can move the ball
{
float miscaOrizontal = Input.GetAxis("Horizontal");
float miscaVertical = Input.GetAxis("Vertical");
Vector3 miscare = new Vector3(miscaVertical,0.0f,(-miscaOrizontal)); //also here i chande the axis for the camera 2
rigidbody.AddForce(miscare * viteza * Time.deltaTime);
}
if(Input.GetKey(KeyCode.E) ) // here when i press E the camera 1 activates and alos i can move the ball if i keep pressing E
{ float miscaOrizontal2 = Input.GetAxis("Horizontal");
float miscaVertical2 = Input.GetAxis("Vertical");
Vector3 miscare2 = new Vector3(miscaOrizontal2,0.0f,miscaVertical2); // here are the controls for the ball for the camera ..i had to change the axis here..
rigidbody.AddForce(miscare2 * viteza * Time.deltaTime);
}
}
}
}
Alright, so if I'm understanding you correctly, you want the ball to move in relation to which direction the camera is currently facing. As well as you don't want to have to hold down "Q" or "E" while you move your ball with WASD controls.
So there are a few things that I'd like to mention here, so we'll take them one at a time. First off, you shouldn't have "AddForce" inside of an Update call. Update is called every frame whenever it can. It's great for input, but generally you want to call it in "FixedUpdate" instead. It provides a better response across many devices. If you leave it in update, you can get inaccurate physics results, and missed collisions. There's a lot out there on this subject, so if you want to know more about it, then just google for a little while.
As for the code side, you want to store a reference to what camera you're using to avoid having to hold these buttons down.
What I mean is:
private Camera referencedCamera = null;
private void Start()
{
referencedCamera = camera1;
}
private void Update()
{
if(Input.GetKey(KeyCode.Q)) referencedCamera = camera2;
else if(Input.GetKey(KeyCode.E)) refrencedCamera = camera1;
}
This way you can reference which camera is being used, rather than a key input. Something else to look into is the "State Design Pattern". Below is a video over the "State Design Pattern." That is a great video tutorial series that Derek Banas put up on design patterns, extremely recommend watching them, but the state pattern could potentially solve this problem for you as well. So that should take care of not having to hold the button down in order to make the move. More or less, the buttons will now allow you to just switch which camera is currently being used.
https://www.youtube.com/watch?v=MGEx35FjBuo
So now that that is solved, you want to transform the input that you currently have, and you want to put it in terms of hte camera that is currently being used. So to avoid rewriting a lot of the code over and over again, just know that these two code snippets should be pieced together into one. So "referencedCamera" should be already defined in the code I'm about to write:
private void FixedUpdate()
{
if(referencedCamera != null)
{
float miscaOrizontal = Input.GetAxis("Horizontal");
float miscaVertical = Input.GetAxis("Vertical");
Vector3 miscare = referencedCamera.transform.TransformDirection(
new Vector3(miscaVertical, 0.0f, -miscaOrizontal));
rigidbody.AddForce(miscare * viteza * Time.deltaTime);
}
}
So now with this, is it's the same code, but there is a call to the referenced cameras transform to take the vector 3 from the input and put it in relation to the camera instead, and add the new relational vector to the object.
I also want to recommend you looking into events rather than if checks in the update function, but that is beyond the scope of the question. Hope this helps and any questions, don't hesitate to ask.
EDIT
After further discussion, we came across something that should also be mentioned. If your camera that you are referencing is angled, the force will be applied in that angle, so keep that in mind. If it is pointed towards an object downward, then forward relative to the camera will apply a force downward, and not entirely in what you may consider the forward direction. Thought it was worth mentioning.
I have an issue with trying to get an 'object(character)' to walk around a cube (all sides) within Unity. Ive attached an image and video showing what i am trying to achieve. Im trying to show you visually rather than trying to explain. As the character drops over the edge it rotates 90 degrees and then the stands up like gravity has switched. Then the character can jump walk etc.
This is an example of someone else that posted a video showing exactly what im trying to achieve
I have looked through the forums and cant find what im after. i have tried to attach a diagram but the site wont let me. Any advice would be greatly appreciated!
Regards
Nick
You have a couple of options that I can think of.
One is to trigger the gravity change when the character exits one face of the cube to go to another. To achieve this you would have trigger zones on each edge and face and use a [Bob went from Face A to Edge ANorth -> Switch Gravity to go in X direction].
This would work for situations where the gravity switch must affect other objects too but be advantageous to your player (walking off the side makes an enemy fall off and die - for example.)
However, if you want all entities to stick to their relative sides then we need to make custom gravity! To do this is easier than you might think as gravity is simply a downward accelleration of 9.8. So turn off the engines native gravity and create a "personal gravity" component:
private Vector3 surfaceNormal;
private Vector3 personalNormal;
private float personalGravity = 9.8f;
private float normalSwitchRange = 5.0f;
public void Start()
{
personalNormal = transform.up; // Start with "normal" normal
rigidbody.freezeRotation = true; // turn off physics rotation
}
public void FixedUpdate()
{
// Apply force taking into account character normal as personal gravity:
rigidbody.AddForce(-personalGravity * rigidbody.mass * personalNormal);
}
Rotating your character and changing his normal is then up to you to suit your situation or game mechanic, whether you do that by raycasting if you're standing on a surface to detect when to change it or only want gravity to change when you hit a powerup or similar - experiment and see what works. Comment more if you have questions!
EDIT:
As an addition to the video you linked. You can keep a state variable on the jump state and raycast in each axis direction to check which face is nearest in the case of just rolling off.
public void Update()
{
// we don't update personal normals in the case of jumping
if(!jumping)
{
UpdatePersonalNormal();
}
}
public void UpdatePersonalNormal()
{
RaycastHit hit; //hit register
// list of valid normals to check (all 6 axis)
Ray[] rays =
{
Vector3.up, Vector3.down,
Vector3.left, Vector3.right,
Vector3.forward, Vector3.backward
};
//for each valid normal...
foreach(Ray rayDirection in rays)
{
//check if we are near a cube face...
if(Physics.Raycast(rayDirection , hit, normalSwitchRange)
{
personalNormal = hit.Normal; //set personal normal ...
return; // and return as we are done
}
}
}
Please keep in mind that the above is completely hand written and not tested but play with it and this pseudo start should give you a good idea of what to do.