I just learn Unity3d for a while, then I have a question about The Camera Follow and Background move are not smooth. I create a cube with ragidbody2d , then i use two dufferent ways to make camera follow :
a. I make the camera in the cube
b. I use Script to control the camera (lateupdate use)
And I add some pictures which are converted into sprite （the size is 1024*512）. I make them to backgound.
when play it , both methods have the same problem, the background move is not smooth, but not completely smooth at all，it will appear from time to time.
I tried the official 2d example found in fast-moving role the backgound is not smooth too. But there are some game made by Unity like badland, when I play it ,there is no this problem.I dont know how to solve this problem, Is the camera configured ? Scirpt? The Type of texture? compressed way? or Need to use some plug-ins?
please help me .thank you .
use "LateUpdate"
LateUpdate is called after all Update functions have been called. This is useful to order script execution. For example a follow camera should always be implemented in LateUpdate because it tracks objects that might have moved inside Update.
It probably because the updates you're using are not synced.
There's the main update (triggered each frame, time between those are different (Time.deltaTime)), FixedUpdate (triggered every physics update, which is a fixed time (Time.fixedTime)) and LateUpdate (every frame, but at the very last).
If you're trying to follow a rigidbody affected by physics, it's recommended to set the camera update function to Late- or FixedUpdate.
You can use it in the Update function if you set the interpolation of the rigidbody in it's inspector:
A rigidody gets an update for it's position every x fixed time, the Update function can be triggered 5 times when FixedUpdate has only been called once, or vice versa. This will give strange results, so setting the rigidbodies interpolation will smooth things out between those unsynced updates.
Also, you can move the camera smoothly by using Lerp methods. an example:
void Update() {
Camera.main.transform.position = Vector3.Lerp(Camera.main.transform.position, targetPosition, Time.deltaTime * 5);
}
more about lerping here
Hope this helps
I found another problem that I don't move camera at all, just move a GameObject which has some pictures as backgound. The Script of Moving GameObject is
Update()
this.transform.Translate(Vector3.right * Time.deltaTime * 40.0f, Space.World);
or
Vector3 pos = this.transform.position;
pos.x += (100.0f * Time.deltaTime);
transform.position = Vector3.Lerp(transform.position, pos, Time.deltaTime * 50);
the reuslt is the background move is not smooth with a visual lag, but not completely smooth at all，it will appear from time to time.
Is there some configures wrong? Graphics Emulation？ or something else ?
Related
I have a problem with physics. It is my first time doing in 3D, so it may be just a beginner mistake.
I just wanted to create a simple player controller and make it so that it can not pass trough cubes.
The problem is that when going straight into the cube, part of the player is in the cube itself. When stop moving, it pushes me, so they are not intersecting (that makes sense).
I tried moving the player using .Transalte, .MovePosition and by changing the velocity of rigidbody itself. None of it change anything. The player can always move a part of him into the cube.
Any ideas how to solve this?
My player controller:
(The 2 lines commented out in Move() are just other ways to move the player.)
using UnityEngine;
public class PlayerController : MonoBehaviour
{
[SerializeField]
private float movementSpeed;
private Vector3 input;
private void Update()
{
GetInput();
}
private void FixedUpdate()
{
Move();
}
private void GetInput()
{
float inputHorizontal = Input.GetAxisRaw("Horizontal");
float intputVertical = Input.GetAxisRaw("Vertical");
input = Vector3.ClampMagnitude(new Vector3(inputHorizontal, 0, intputVertical), 1);
}
private void Move()
{
GetComponent<Rigidbody>().velocity += input * movementSpeed;
//GetComponent<Rigidbody>().MovePosition(GetComponent<Rigidbody>().position + input * movementSpeed * Time.deltaTime);
//transform.Translate(input * movementSpeed * Time.deltaTime, Space.World);
}
}
Player is standing still
Player is moving towards cube
Settings of the Game Objects itself
Now I think I understand your problem.
The collider is a geometric shape that is checked but the outcome wont take place until the collision has actually taken place, this means, one geometric shape being inside the other. By this I mean, that what you are experiencing is the normal behaviour of the collision. If both elemnts are rigid bodies, both will move and your problem wont be perceivable, but if your cube is not a rigid body or is kinematic, will stand still in the same position, and depending on the other object speed, its normal that an invasion/superposition of the elements is perceivable, because that is the frame were the collision took place, and were your element needs to be moved back because it has collided.
Consider that if the speed is high enough, and the position from one frame to another varies enough, the collision might not even take place, because the geometric parts do not interfere between frames, as the position variation might be bigger than the bounds of the collider itself. The collision check at the end of the day, is dicrete, and not continuous (even you can set it as continuous to be as frecuent as possible).
To solve or improve that, you can adjust the speeds to avoid that being perceivable + adjust your collider to make it react before the graphic superposition occurs. This means making the capsule or the cube collider bigger than the graphic element itself. You can even calculate , to make it as bigger as much as your your speed * Time.deltaTime result or speed * FixedTimeStep result, depending on your safety distance needs. I think one of those should be the safety distance you need to take into account before the graphic collision occurs.
Another thing you can do is tight more the times physics calculations are done.
https://docs.unity3d.com/Manual/class-TimeManager.html
But need to be careful with this as this can be a performance devourer and need to be handled with care. You can make some trials with that and check your problem can improve.
Hope that helps
You can increase the scale of your player's collider from the Collider component attached to it. You can check how big the collider is from the editor scene view.
Edit: The issue might be that your movement or collision code is called in Update instead of FixedUpdate. When working with rigidbodies, you want to call the physics calculations inside FixedUpdate.
remove rigidbody from the cube, you can click on 'Gizmos' in the top right of the editor and make sure the colliders are at the edges of the objects.
I make a 2D-game. In this game, I have a projectile, which I move the fires by myself like this:
void Update()
{
gameObject.transform.position = new Vector3(
gameObject.transform.position.x + baseVelocity * Time.deltaTime,
gameObject.transform.position.y + baseVelocity * Time.deltaTime,
gameObject.transform.position.z);
}
And also, I use void OnTriggerEnter2D(Collider2D other) to know when collisions occurs.
The problem is when game running on a weak phone with 30-FPS it won't detect collision, while same fire in an 60-FPS phone will collide.
I think this is because the fires move 2x more in 30-FPS phones.
One option was use FixedUpdate() method for moving fiers, but it gave me jerky movement, and I used Update() method for moving because it gives me smooth movement(in both of them I used Time.deltaTime).
Can you please suggest me how make more accurate while using smooth movement?
like move object in Update() method but check object position in more(offset) positions than where it is!
I forget to note that I changed the value of Fixed TimeStep to 0.01 for getting more accurate physics.
Thanks in advance.
edit:
I finally end up with using FixedUpdate() for move objects by myself, for so many reasons I can't use Physics engine, I set FixedUpdate TPS(tick per second) around 60 to some how be match with my 60 FPS Update (and still can't figure out why increase FixedUpdate TPS will make object movement jerky!).
And will keep this question open for finding better answer.
You seem to be doing the physics manually. The issue with manually updating the position is that you don't know about the position of your projectile between frames. Even if you were to use FixedUpdate, you could still be in the situation where two FixedUpdate calls cause your projectile to miss an object.
So instead of manually updating the position, you should use a RigidBody2D, with the collision detection set to "Continuous". A continuous collision detection will interpolate object collision in between physics update cycles, so you hit your target even at very high speeds. Also, this solution does not depend on frame rate.
Note that the above will only work if you don't manually update your positions yourself. That is because the physics engine uses velocity to calculate collision in between physics update cycles.
So instead of updating the position yourself (which is bad for physics), use forces instead.
Or alternatively, if you don't want to mess with forces, update the velocity instead:
GetComponent<RigidBody2D>().velocity = baseVelocity;
I am setting constant velocity for my character movement in my 2D game. However since using the method my character seems to be shaking a little. Is there a way to fix this and smooth the movement out?
Here is I set the velocity in the Update function:
constantVelocity = new Vector3 (playerInputX * speed, playerInputY * speed, 0);
I then apply this velocity to the the Rigidbody2D component in the FixedUpdate function.
It turns out that my problem had nothing to do with the object I was moving but the camera that was following it. The camera was trying to Lerp towards the object in Update. I changed this to FixedUpdate and it now works perfectly.
Thanks for the help anyway,
Tommy
There are two ways to do this.
You can always use Time.fixedDeltaTime to smoothen your player movement.
You can try low pass filtering on our constantVelocity.
I am trying to move my player by using rigidbody.velocity:
rigidbod.velocity = new Vector2 (Input.GetAxis ("Horizontal") * maxSpeed, rigidbod.velocity.y);
the problem is, this messes up of my explosion code. The character is supposed to be knocked back when near an explosion. I know why it happens; if the player is still, the rigidbody's X velocity would be returned as 0, meaning any outside forces pushing the player along the X axis would counteract this. So when I add the explosion, the player cuts to his new position a few units away. It looks very unnatural and jerky, as he should be pushed back, but his code is telling him to be still unless a key is pressed. I'm posting this to see if there's any way I can re-write this code to be able to move the player while being pushed correctly from outside forces. I heard that AddForce works, but when I used it, my player's velocity constantly increased. He is wither way too fast or way too slow. Any ideas on how I can get this to work? I tried adding rigidbody.velocity.x after where it says 'maxspeed' hoping that it would allow outside force input, and it works, but it messes up the movement code, making him go way too fast. I can't seem to get both the explosions and the movement code to work correctly at the same time. Any help would be greatly appreciated. Thanks.
which is exactly why in the Unity docs they explicitly state:
In most cases you should not modify the velocity directly, as this can
result in unrealistic behaviour.
instead of modifying the velocity directly, you should be using an AddForce(..)
Vector2 force = new Vector2 (Input.GetAxis ("Horizontal") * maxSpeed, 0f);
rigidbody.AddForce(force);
//or if in update:
rigidbody.AddForce(force * Time.deltaTime);
I am trying to build a 2D space shooter game where the player will remain constant at the bottom of the screen and will move left and right. When the player fires a bullet(projectile), the bullet is going up just fine, but it is coming back again. Also if two bullets collide, they react to the collision.
I have two questions here:
How can I ensure that the bullet does not come back? (One way is to destroy it after a few seconds, but not sure if this is the right way)
How do I avoid collision between the bullets.
Here is my code snippet:
void Update () {
if (Input.GetButtonDown("Fire1"))
{
Rigidbody2D clone = (Rigidbody2D)Instantiate(bullet, transform.position + transform.up, transform.rotation);
clone.velocity = transform.TransformDirection(Vector3.up * 20);
}
}
I am very new to Unity and somehow wrote this code by looking into Unity Forums.Any help will be very much appreciated.
Thanks
More details:
I have created the bullet and added Rigidbody2D and a BoxCollider2D for this object. Made the bullet object a prefab and I dragged it under the Player object. Now bullet is a child of the Player object. Attached the script above to the Player object.
To answer your immediate questions:
1) I am not too sure about how you have the scene setup or about using the Unity 2D tools but usually if your bullets are coming back down then I would assume that you still have gravity applied to the rigidbody -- so make sure that you have that unchecked.
2) With Unity3D for objects to interact with each other they need rigidbodies attached. This is vital, say, if you want your lasers to destroy Monster #1. However, you only need one rigidbody attached to an object to have a desired effect. I would suggest removing the rigidbody from your laser and attach rigidbodies to objects ( Monster #1 ) that you want to be affected by the laser fire. ( That should work, if not there are other options -- one using layers and ignoring particular objects on those layers ).
Tips:
Here are some extra things. When you are creating objects and they fly off screen over time they will build up. Imagine you are in a large battle and you instantiated hundreds of lasers -- it will eventually be an issue for performance. So always consider Destroying objects after a certain amount of time.
Also, after looking at your code, I can't tell whether the velocity of the object is based upon its current position and nothing is being added. What I think is happening is when you instantiate an object it may be moving up, but because there is no incrementer, the object ( as it gets higher ) slows until it is at a rate which it is falling. For example this
clone.velocity = transform.TransformDirection(Vector3.up * 20);
should probably do this:
clone.velocity += transform.TransformDirection(Vector3.up * 20);
Heres http://docs.unity3d.com/Documentation/ScriptReference/Vector3-up.html, to read up on velocity. The problem is is that you need to continuously apply a constant forward motion so things in motion will tend to stay in motion. If not gravity will pull it down.
Also, heres a bit of code that I've used in the past that's created a pretty cool shooting laser effect thing:
public class Laser : MonoBehaviour {
public int fireRate = 70;
void Start(){
InvokeRepeating("FireLaser", 0.01f, 0.009f);
Destroy( gameObject, 2.0f );
}
void FireLaser(){
transform.Translate( Vector3.up * fireRate * Time.deltaTime );
}
}
edit: it's 3 a.m. and I hate proofreading.