How can I make GameObjects translate across the screen smoothly in Unity? - c#

Basically, I have a game where tickets appear at the top of the screen. When a ticket is completed, it gets destroyed, and if there's a gap between the remaining tickets, the tickets slide down to fill in the gap. I actually have it working just fine, but they kind of just jump to the positions and it doesn't look very pretty.
How can I move the objects to their target position smoothly? I've tried messing with Lerp and Smoothdamp, but both of those seem to be producing strange results (tickets go all over the place. Here's the relevant code I'm working with:
public void SlideRail()
{
ticketList.RemoveAll(x => x == null);
int count = ticketList.Count;
for (int i = destroyedIndex; i < ticketList.Count; i++)
{
if (ticketList[i] != null)
{
ticketList[i].transform.Translate(Vector3.left * 35);
ticketList[i].GetComponent<Ticket>().index--;
}
}
indexer = railPosition.IndexOf(ticketList.Last().GetComponent<Ticket>().item_pos);
up = false;
}
DestroyedIndex is the index of the object that was destroyed (so that we only move the objects after it in the list)
Up is a flag that activates SlideRail(), when its set to false the method ends and the next method continues.
SlideRail is then called in the Update() method:
void Update()
{
if (up && ticketList.Count > 2)
SlideRail();
if (Time.time > nextTicket)
{
nextTicket = Time.time + timeBetweenTickets;
StartCoroutine(WaitToPrint());
CreateTicket();
UpdatePosition();
}
}
I feel like I should be able to do this using Translate, but I must be missing something.

With movement like this you should usually include Time.deltaTime (as a factor in translate) to bind the movement to the frame rate. [Edit: Translate this sentence to framerate-independant, that's what I meant.]
Now, to the actual point, it looks like you do the movement in just one frame and thus you get this jump (you always set up to false at the end of SlideRail).
A possible way of doing this is to specify a target position upon trigger (task complete, need to push over) and than keep calling ticketList[i].transform.position = Vector3.MoveTowards(ticketList[i].transform.position, targetPosition, speed * Time.deltaTime); for each object (framed by a "reached target position" check, e.g. using if(Vector3.Distance(ticketList[i].transform.position, targetPosition) > someThreshold). You can add an else to this to directly set the position when in threshold range (make the threshold small so it's not visible, e.g. 0.1f), though you usually only need this for non-linear functions like lerp which slow down at the end and can stall. [Edit: Because of floating point imprecision it's actually mostly always a good idea to use a threshold.]

Using iTween, it can be simplified into a one line call:
iTween.MoveTo(someGameObject, iTween.Hash("y", targetY,
"islocal", true,"easetype", iTween.EaseType.spring,
"time", 0.2f));

I've wrote this piece of code for myself before, maybe it helps you.
using System;
using System.Collections;
using UnityEngine;
public class MoveController : MonoBehaviour
{
public float moveTime;
public AnimationCurve moveSpeedCurve;
public AnimationCurve movePositionCurve;
public void StartMoving(Vector2 destination, Action action = null)
{
StartCoroutine(Move(destination, action));
}
IEnumerator Move(Vector3 destination, Action action = null)
{
float currentTime = 0;
float perc = 0;
Vector3 currentPos = transform.localPosition;
while (perc != 1)
{
currentTime += Time.deltaTime;
if (currentTime > moveTime)
{
currentTime = moveTime;
}
perc = moveSpeedCurve.Evaluate(currentTime / moveTime);
transform.localPosition = Vector2.LerpUnclamped(currentPos, destination, movePositionCurve.Evaluate(perc));
yield return null;
}
if (action != null)
action();
}
}

Related

How do I make a platform go down after a certain amount of time not colliding with the player object in Unity?

I'm new to Unity and C# in general, so excuse my terminology(or lack thereof)...
I have succeeded -with the help of a friend, to credit where its due- in making a platform go up a certain amount after one frame of collision with the player! The only problem is that, now, I can't seem to get it moving down again... Said friend challenged me to make it go up, stay airborne for a certain amount of time, then go back down.
Here is a snippet of my working code that makes it go up.
bool HaveCollided = false; //Collision checker boolean
void Update()
{
Vector3 up = lifter * Time.deltaTime;
if (HaveCollided != true || transform.position.y >= 5)
{
return;
}
}
void OnCollisionEnter(Collision collision) //Makes HaveCollided true at collision event
{
if (collision.gameObject.GetComponent<Playertag>() != null) //don't use GetComponent in Update()
{
HaveCollided = true;
}
So if my logic is right, I'd need to nest another if statement inside the one where the condition is: HaveCollided != true || transform.position.y >= 5 which should be:
if (newTime == Time.deltaTime * CertainAmount && transform.position.y >= 1) //make platform go down until y position is equal to 1
{
//make platform go down
Debug.Log("reached");
transform.position = transform.position - up;
}
But it's not working. It doesn't even seem to reach the part that would make the platform descend. I literally do not know where to go from here...
Based on your comment I made a few revisions to make the platform movement a bit smoother. I also made it so the same function can be used for both the upward and downward motion.
using UnityEngine;
using System.Collections;
[SerializeField] private float timeToMovePlatform = 0.0f; // time it takes the platform to get from 1 point to another
[SerializeField] private float timeToRestAtPeak = 0.0f; // time that the platform rests at the top of its movement
[SerializeField] private float platformYOffset = 0.0f; // offset the platform moves from its origin point to float upward
private Coroutine movingPlatform = null; // determines if the platform is currently moving or not
private void OnCollisionEnter(Collision col)
{
// add a tag to your player object as checking a tag at runtime vs. a GetComponent is faster
if(col.gameObject.tag == "Player")
{
// only trigger when we are not currently moving
if(movingPlatform == null)
{
// start our coroutine so the platform can move
movingPlatform = StartCoroutine(MovePlatform(true));
}
}
}
/// <summary>
/// Moves this object up or down depending on the parameter passed in
/// </summary>
/// <param name="moveUpward">Determines if this object is currently moving upward or not</param>
private IEnumerator MovePlatform(bool moveUpward)
{
// store our start position
Vector3 startPos = transform.position;
// build our goal position based on which direction we are moving
Vector3 goalPos = new Vector3(startPos.x, startPos + (moveUpward ? platformYOffset : -platformYOffset), startPos.z);
// set our current time
float currentTime = 0.0f;
while(currentTime <= timeToMovePlatform)
{
// lerp the position over the current time compared to our total duration
transform.position = Vector3.Lerp(startPos, goalPos, currentTime / timeToMovePlatform);
// update our timer
currentTime += Time.deltaTime;
// need to yield out of our coroutine so it does not get stuck here
yield return null;
}
// just in case there are any floating point issues, set our position directly
transform.position = goalPosition;
// when we are moving upward, make sure to stop at the peak for the set duration
if(moveUpwards)
{
yield return WaitForSeconds(timeToRestAtPeak);
// once we are done waiting, we need to move back downward
StartCoroutine(MovePlatform(false));
}
else
{
// we finished moving downward, so set our coroutine reference to false
// so the player can set the platform to move again
movingPlatform = null;
}
}
Fair warning, I did not test this code it is more a direction I would take for your situation. Before doing anything, add a tag to your player. If you are unsure what tags are, check out the docs. Be sure to give the player the tag Player so that the code will work as expected.
You will notice the first three variables are Serialized but are private. By doing this, it allows for Unity to show them in the inspector but not allow other scripts to touch them.
To learn more about Coroutines, check out the docs and for Lerps, I enjoy this blog post. Let me know if this works for you and/or you have any questions.
Your best bet is to add colliders and use isTrigger. Seed a time and if it's not triggered within that time period raise an event.

How do I create an object to move between two positions in unity, using C#, and why is my code not working?

I have this piece of code right here that should make the block object move between the startPos and endPos objects, but something is wrong about it and I don't know what.
void FixedUpdate()
{
if (block.transform.position == startPos.transform.position)
{
check = false;
}
if(block.transform.position == endPos.transform.position)
{
check = true;
}
if (check == false)
{
block.transform.position = Vector3.Lerp(block.transform.position, endPos.transform.position, .03f);
}
if (check == true)
{
block.transform.position = Vector3.Lerp(block.transform.position, startPos.transform.position, .03f);
}
}
At some point the block will reach endPos, and then on its way back to startPos it will stop, because the functions will be executed simultaneously. But how is this possible because my if's right there should not allow this to happen?
In general you should always be using
Update &rightarrow; called every frame
instead of
FixedUpdate &rightarrow; called in certain realtime intervals
except you are dealing with Physics somehow (which doesn't seem to be the case here). Also see the Update and FixedUpdate Tutorial
The issue with Vector3.Lerp is that it doesn't behave as you expect.
I guess you like that it starts fast and then becomes "smooth" ... but actually this might be your problem.
It never reaches the target position really. It just gets closer and closer and slower and slower ...
... until at some moment the == with a precision of 0.00001f eventually becomes true.
So it might seem that it stopped but actually it might still be moving just really really slow.
For the following two alternatives you have to decide a bit what you want to control:
Option: The speed
If you want to have a linear velocity for the object you should rather use
// adjust via the Inspector
[SerializeField] private float moveSpeedInUnityUnitPerSecond = 1f;
// you should use Update here in general
void Update()
{
if (block.transform.position == startPos.transform.position)
{
check = false;
}
// always use else in cases where only on condition can be
// true at the same time anyway
else if(block.transform.position == endPos.transform.position)
{
check = true;
}
block.transform.position = Vector3.MoveTowards(block.transform.position, check ? startPos.transform.position : endPos.transform.position, Time.deltaTime * moveSpeed);
}
Option: The duration
If you rather want a smooth movement but control the duration it takes to reach the target you should use a Lerp but with a factor depending on the time like
// adjust via the Inspector
[SerializeField] private float moveDurationInSeconds = 1f;
private float passedTime;
// you should use Update here in general
void Update()
{
// prevent overshooting
passedTime += Mathf.Min(moveDurationInSeconds - passedTime, Time.deltaTime);
if(passedTime >= moveDurationInSeconds)
{
check = !check;
passedTime = 0;
}
var lerpFactor = passedTime / moveDurationInSeconds;
// and now add ease-in and ease-out
var smoothedLerpFactor = Mathf.SmoothStep(0, 1, lerpFactor);
var fromPosition = check ? endPos.transform.position : startPos.transform.position;
var toPosition = check ? startPos.transform.position : endPos.transform.position;
block.transform.position = Vector3.Lerp(fromPosition, toPosition, smoothedLerpFactor);
}
For this you could also use a Coroutine which usually is a bit easier to interpret and maintain:
// adjust via the Inspector
[SerializeField] private float moveDurationInSeconds = 1f;
// yes you see correctly one can directly use the Start
// as a Coroutine
private IEnumerator Start()
{
var fromPosition = startPos.transform.position;
var toPosition = endPos.transform.position;
// looks strange but as long as you yield somewhere inside
// the loop it simply means repeat the sequence forever
// just like the Update method
while(true)
{
var passedTime = 0f;
while(passedTime < moveDurationInSeconds)
{
var lerpFactor = passedTime / moveDurationInSeconds;
// and now add ease-in and ease-out
var smoothedLerpFactor = Mathf.SmoothStep(0, 1, lerpFactor);
block.transform.position = Vector3.Lerp(fromPosition, toPosition, smoothedLerpFactor);
passedTime += Mathf.Min(moveDurationInSeconds - passedTime, Time.deltaTime);
// reads like: "pause" here, render this frame and continue
// from here in the next frame
yield return null;
}
// once reached flip the positions
var temp = fromPosition;
fromPosition = toPosition;
toPosition = temp;
}
}
in both cases you could still add more flexibility and instead of simply using the moveDurationInSeconds use
var fixedDuration = moveDurationInSeconds * Vector3.Distance(fromPosition, toPosition);
this way the movement takes shorter if the positions are closer together and longer if they are further apart. This comes pretty close to the Lerp you used before regarding to the smoothness of motion but you can control very good how long the movement will take.
The third argument of Vector3.Lerp is a percentage of the distance between the first two arguments. When you pass in 0.03f, you're getting 3% closer to your end position but never actually getting exactly there (You can prove this by logging the block's position and the target's position and you'll see they're never perfectly equal).
Instead of checking if your block's position with the == operator (which works to an accuracy of 0.00001f) to the target position, you could simply check if it's close enough with Vector3.Distance:
if(Vector3.Distance(block.transform.position, endPos.transform.position) < 0.1f) {
You can make your "close enough threshold" (0.1f in the example) a named variable for easy adjustment until it feels right.
For starters, Update() loops every frame. FixedUpdate() depends on the number of frames per second set in the time setting. So, put your code into Void Update() instead.
If you refer to Vector3.MoveTowards documentation, you may find a much better approach to your problem.
The script below should do the trick. The target variable should be set to the position of your end point. Speed is how fast your object should move.
Inside Update(), the step variable is used to determine how far the object should move based off its speed and the time elapsed since it last moved. Finally, the last line changes the position of the object and records the new position.
public Transform target;
public float speed;
void Update() {
float step = speed * Time.deltaTime;
transform.position = Vector3.MoveTowards(transform.position, target.position, step);
}

Counting a full rotation with a circular drive

I've been raking my brain for the last day on how to calculate a full rotation with how to count a full rotation of an object along the X axis thats using the base circular drive from SteamVR.
I thought a simple 3d cube, with the mesh turned off in the the path of the rotation with collision code on it would be a barebone way of doing it, but it doesn't even seem to be registering the detection when the object hits the placed cubes, and i know its not because of me being stupid, as its recycled code from a working part of the project.
Below i have a small piece of code that basically detects when the object has reached the end of the rotation, and then increments the Count by one.
My main problem is that sometimes it manages to clock more than once, and if you can find the right spot, you can just keep it there and it'll keep on adding the count up by. Im wondering how i can stop it and increment only by one, until another full rotation has been made?
EDIT: to be more clear in case there is any confusion, Once the angle is clocked in between 359 and 360, i want it to increment once, whereas currently if you get the angle to sit anywhere in between 359-360 it will carry on adding one to the rotation count, despite no full rotation having been made, so im trying to figure out how to make my code only increment once, and once it does increment once it resets the position to zero, so therefore no more Increments can happen. It's a crank mechanism in VR, along the X axis.
Any help is appreciated, Thanks!
float Test;
float RotationCount = 0;
// Start is called before the first frame update
void Start()
{
// Test = transform.localRotation.eulerAngles.x;
}
// Update is called once per frame
void Update()
{
if (Test > 359 && Test < 360)
{
Debug.Log("Clocked");
count();
}
else
{
// Debug.Log("Nope");
}
if (Test == 0)
{
Debug.Log("Yes");
}
Test = transform.localRotation.eulerAngles.x;
}
void count()
{
RotationCount++;
}
sometimes it manages to clock more than once, and if you can find the right spot, you can just keep it there and it'll keep on adding the count up by.
well in
if (Test > 359 && Test < 360)
{
Debug.Log("Clocked");
count();
}
what happens if your angle is e.g. 359.5?
It is very difficult to just take a current rottaion and know whether it was turned more or less than a certain angle.
I'ld rather store the last rotation, compare it to the current one and add the difference to a variable. Than if the variable exceeds 360 a full rotation was done. Since I also don't like to calculate anything with Quaternion and eulerAngles, way simplier is to use the methods provided by Vector3.
For the local rotation around X (== transform.right) I would use the angle between the current and the last transfrm.up vector.
Something like
public class RotationCheck : MonoBehaviour
{
public int RotationCount;
public float rotatedAroundX;
public Vector3 lastUp;
public UnityEvent On3TimesRotated;
private void Awake()
{
rotatedAroundX = 0;
// initialize
lastUp = transform.up;
}
private void Update()
{
var rotationDifference = Vector3.SignedAngle(transform.up, lastUp, transform.right);
rotatedAroundX += rotationDifference;
if (rotatedAroundX >= 360.0f)
{
Debug.Log("One positive rotation done", this);
RotationCount++;
rotatedAroundX -= 360.0f;
}
else if (rotatedAroundX <= -360.0f)
{
Debug.Log("One negative rotation done", this);
RotationCount--;
rotatedAroundX += 360.0f;
}
// update last rotation
lastUp = transform.up;
// check for fire the event
if (RotationCount >= 3)
{
On3TimesRotated?.Invoke();
RotationCount = 0;
}
}
}
You can use a UnityEvent to get the same thing the Button uses for onClick so you can reference callbacks there via the inspector.
BUT if you don't care about the single rotations but actually only wnat the final RotationCount >= 3 I would actually use
private void Update()
{
var rotationDifference = Vector3.SignedAngle(transform.up, lastUp, transform.right);
rotatedAroundX += rotationDifference;
RotationCount = Mathf.RoundToInt(rotatedAroundX / 360.0f);
// update last rotation
lastUp = transform.up;
// check for fire the event
if (RotationCount >= 3)
{
On3TimesRotated?.Invoke();
RotationCount = 0;
rotatedAroundX = 0;
}
}
which directly reduces the value by one if rotated under the 360 mark instead of waiting for a full negative rotation
*as you can see instead of reaching 3 the RotationCount is reset to 0. This is where the On3TimesRotated event is/would get fired.

How can I get the camera to pause on 3 objects on the x axis?

I am a new student working on a class project. I have 1 script attached to the camera in my only scene. I want the camera to pause over the 1st object, scroll to the 2nd object and pause then scroll to the 3rd object and pause then end. Putting this code in the UPDATE, the camera never stops. Here in the START, it hesitates around 15 sec and then it goes right to the last object, then the function stops. Note the delay set for 10 seconds. I tried putting the code in a function and calling the function from START… but no good. What am I doing wrong? HELP ME OB1....
One more thing... Is START the best place to play sound?
using UnityEngine;
using System.Collections;
// I want the camera to pause over the 1st object, scroll to the 2nd object and pause
// then scroll to the 3rd object and pause then end. Putting this code in the UPDATE
// the camera never stops. Here in the START, it hesitates around 15 sec and then it
// goes right to the last object, then the function stops. Note the delay set for 10
// seconds.
public class CameraControl : MonoBehaviour
{
public float speed; // How fast to move the camera
public int moves; // How many moves to make
public float MyWait; // How long to pause over object
// Use this for initialization
void Start()
{
StartCoroutine(MyDelay());
for (int y = 1; y <= 2; y++) // go to the next two objects
{
for (int i = 1; i <= moves; i++) // Move the camera to the next position
{
Camera.main.transform.Translate(new Vector3(1.0f, 0.0f, 0.0f) * speed * Time.deltaTime);
Debug.LogFormat("moves = {0} ", i);
}
StartCoroutine(MyDelay());
}
}
IEnumerator MyDelay()
{
yield return new WaitForSeconds(10.0f);
}
}
Try placing this code on your camera and place all the game objects you'd like the camera to move to in the Objects list. If you'd like the camera to be a little further back so it can see the object, create a new Vector3 instead of simply giving the exact position and then give that new Vector3 the x, y and z of the iterating object and then add distance to which ever axis you'd like for the camera to be distanced from the object.
public float MyWait = 5; // How long to pause over object
public float speed = 5f; // How fast to move the camera
public List<GameObject> Objects; //List of each object for the camera to go to
void Start()
{
StartCoroutine(MoveToObject(0));
}
IEnumerator MoveToObject(int iteratingObject)
{
//Wait for however many seconds
yield return new WaitForSeconds(MyWait);
bool atDestination = false;
//Move the camera until at destination
while (!atDestination)
{
yield return new WaitForFixedUpdate();
transform.position = Vector3.MoveTowards(transform.position, Objects[iteratingObject].transform.position, Time.deltaTime * speed);
if (transform.position == Objects[iteratingObject].transform.position)
atDestination = true;
}
//Continue iterating until moved over all objects in list
if(iteratingObject != Objects.Count - 1)
StartCoroutine(MoveToObject(iteratingObject + 1));
}
I think you're going to need to put some code in the Update function for this to work smoothly.
Time.deltaTime will only really make sense in an Update function, using it here and trying to do everything in the Start function won't work. Also setting the Translate transform will instantly set the position to the given value. Look up linear interpolation (lerp).
I would suggest you have a member that you use to track the current state, i.e. which object you're looking at, but an Enum of states might be easier to read.
Then you can keep a member for how long you've been in that state, which you can increase in the Update.
Then within the Update you can check whether it is time to change state or update your moving camera.
Good luck!

Moving a 3d object back and forth between points

I tried to make a script that moves an object back and forth between two points. But it just flies in the ifinity. I tried to find the problem whole evening but idk.
here is the code:
using UnityEngine;
public class MovementBetweenPoints : MonoBehaviour {
public Transform[] keyPoints;
public float speed;
private int currentKeyPoint;
// Use this for initialization
void Start ()
{
transform.position = keyPoints[0].position;
currentKeyPoint = 1;
}
// Update is called once per frame
void Update ()
{
if (transform.position == keyPoints[currentKeyPoint].position)
{
currentKeyPoint++;
}
if (currentKeyPoint >= keyPoints.Length)
{
currentKeyPoint = 0;
}
transform.position = Vector3.MoveTowards(transform.position, keyPoints[currentKeyPoint].position, speed * Time.deltaTime);
}
}
Your script works fine as it is. you need to make sure that speed is set to a value greater than 0 in the inspector, and that the keypoints array contains some gameobjects in the inspector too, and you are good to go
I'm sure the problem comes with this part of the code where you check if the position of the object is equal at some waypoint. Instead of:
if (transform.position == keyPoints[currentKeyPoint].position)
{
currentKeyPoint++;
}
try to do something less agressive, and give a bit of margin like:
if (Vector3.Distance(transform.position - keyPoints[currentKeyPoint].position) <= min_Distance)
{
currentKeyPoint++;
}
because it's almost impossible that two objects with different speeds match at the same point. Instead of this, you'll use min_Distance to check it.

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