I'm trying to create collidable noodle which get pushed by other objects in my game.
I tried to create rigged/skinned mesh in Blender then connect the bones with joints in Unity and tried all of the joints with various settings, but it jitters when bit more than minimum force applied to these bones. Then i tried to bind these bones with script to keep fixed distance from connected bones (next or previous bone) which relative to only one bone/side which works well if it's pulled from one end; but i need it to be relative to both sides to act like noodle. The skinned mesh does the job of keeping it whole, so i think i need some way to control these bones/segments. Any help will be appreciated. Thanks a lot for your time, effort and consideration :).
Script for every node to keep the fixed distance:
void Update() {
// To keep initial distance
Vector3 vec = connectedNode.position - transform.position;
if (vec.magnitude > initialDistance)
transform.position +=
(vec.magnitude - initialDistance) * vec.normalized;
}
Related
Game: In a simple 2D Portrait Game made in Unity, I have a GameObject (Player) that has a fixed location and which is moving upwards. The Camera follows the Player and animated Obstacles are spawning from time to time moving left to right. The attached Screenshot shows the Scene.
The Problem:
The Movement is not smooth, as it seems like the Player is jittering. I think I already identified one of the causes: Big variation of Time.deltaTime. Average value is 0.0167, but I had variations. Minimum was 0.00177, maximum value was 0.2249519.
Settings:
Target Framerate is 60. I use Unity 2019.4.2f1 and as build target an iPhone X with iOS 14.2.
Scripts
public class Player: MonoBehaviour
{
float speed = 5f;
void Update()
{
transform.Translate(0,speed*Time.deltaTime,0);
}
}
public class CamFollow : MonoBehaviour
{
public Transform Player;
private Vector3 FollowVector;
void LateUpdate()
{
FollowVector = Player.position - new Vector3(0, -4.0f, 10);
transform.position = Vector3.Lerp(transform.position, FollowVector, Time.deltaTime * 4f);
}
}
Note: I need to use Lerp, because the Player may lower or increase the speed for one second, then the camera gently moves to the new position, before changing back. For the Obstacles I don't have a Script. They are moving, by using the Animation Component. For the Obstacles I only loop a change of the x value of the position.
My alternative solutions:
1. Changing the value for Time.deltaTime to a constant value of 0.01666667f:
void Update()
{
transform.Translate(0,speed*0.01666667f,0);
}
This makes the Player Object jitter a lot in the Unity Editor but only a little on the device
2. Using Fixed Update both for the Camera Follow and the Player Movement
This makes the movement and camera follow perfectly smooth, but the animated objects jitter a lot. I know Unity wants to adress the deltaTime issue in one of the next updates. But there should be a solution for my problem, so did anybody have a similiar problem, which could be solved? I prefer the 2nd alternative, because the movement looked really smooth and nice, so can I somehow make the animation part of "fixedUpdate"?
The variation in the 'deltaTime' is to be expected.
The variation is large on the PC because you are running on a complex computer with a complex operating system and lots of other applications running simultaneously, each with a multitude of threads, which every once in a while want to do some work. Thus, the scheduler of the operating system cannot guarantee that you are going to get a time slice at the precise moment that you want it in order to render your next frame.
The variation is smaller on the mobile device because it is a much simpler machine with a lot less going on, so the scheduler is able to give you time slices close to the precise intervals that you are asking.
You are already taking this variation into account when you do
transform.Translate( 0, speed * Time.deltaTime, 0 );
This is a fundamental technique in game development: the frame rate is never constant, so the distance by which you must move an object on each frame depends on the precise amount of time elapsed between this frame and the previous frame.
So, that part is fine.
Your problem lies in
transform.position = Vector3.Lerp( transform.position, FollowVector, Time.deltaTime * 4f );
Here you are passing Time.deltaTime * 4f for parameter t of Vector3.Lerp(). I have no idea what you are trying to accomplish, but the number you need to pass there needs to be a gradual transition between 0 and 1, and instead you are passing a randomly varying number of seconds multiplied by some magic constant 4. This does not look correct.
A couple of options that I can think of:
Always use 0.5 for t so that the camera always rushes to the right position and then slows down as it gets closer to it.
Calculate a separate speed vector for the camera, then move the camera using a translation just as you do for the player.
I know the title isnt very explanatory, but here's my problem:
I have a player (merely a cube with a rigidbody, a collider and a movement script), and I have a floor made of small 1 by 1 by 1 cubes (cubes with box colliders).
For some reason unknown to me, when my player cube falls and tries to collide horizontally with the floor, he just phases through... But want him to get blocked by the cubes just like it does vertically. Any help would be greatly appreciated ;)
heres how the scene looks like
heres a cube object
heres the player object
Here's a gif of the player going through the floor
Here's my c# player movement script (I know its very bad, but I prefer to put this here just in case its linked to my problem) :
void ApplyMovement()
{
transform.position += new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
}
If you need any more info to help me just tell me, I'll provide it as fast as I can.
The value of
new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"))
is framerate-dependent. This means the faster the framerate the faster your object will move. This is usually not what you want. Instead use Time.deltaTime
// Adjust the speed in the inspector
public float speedMultiplicator = 1;
//...
new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical")) * speedMultiplicator * Time.deltaTime
to get a framerate-independent movement. Also see the example in Input.GetAxis.
When dealing with RigidBody never change the transform.position (and rotation) directly!
If you would want to make the RigidBody jump to a certain position rather use
rigidBody.position = transform.position + ...;
However what you want is a smooth movement in order to keep the collision detection intact. So you should use RigidBody.MovePosition instead
rigidBody.MovePosition(transform.position + ...);
You don't have to deal with force etc.
Also add a RigidBody component to the floor objects. Even ifnthe object is not moving this improves the collision detection (at the cost of performance in the Physics engine ofcourse). And since the objects are not supposed to move set
isKinematic -> true
use Gravity -> false
you can also set freeze position and freeze rotation.
On both floor and player objects set Collision Detection -> Continous Dynamic. This improves the collision detection and looks for collisions also between frames.
Be aware, however, that dynamic detection is quite expensive so use it only if there is still trouble with too fast objects.
On the player you might want to also use interpolate as well.
Finally
Note that continuous collision detection is intended as a safety net to catch collisions in cases where objects would otherwise pass through each other, but will not deliver physically accurate collision results, so you might still consider decreasing the fixed Time step value in the TimeManager inspector
to make the simulation more precise, if you run into problems with fast moving objects.
For more information see the RigidBody manual and the Colliders manual
I recreated the scenario you described on my end. I put your "ApplyMovement" code in "Update". I was basically able to reproduce your results.
It seems to me that the issue might be Freezing Position X/Z on the Player. I think since you are doing that, you're telling the Rigidbody component that it is not allowed to modify the X/Z positions of the objects as part of it's collision resolution and physics simulation. When I turn those two off, I get results that are (I think) closer to what you're looking for.
One note: your "ApplyMovement" code is frame-locked, meaning your player will move at different speeds at different frame rates. To solve this, you'd need to multiply your Input.GetAxis values by Time.deltaTime.
Also, if your player moves too fast, it'll still be able to pass through collisions and cause odd behavior, so be sure to limit the max movement rate of the player to some reasonable value.
You should be applying a force to the Rigidbody of the character instead of directly manipulating the transform.position (this is preventing the physics engine from resolving the collisions). You're also freezing the X and Z position on the Rigidbody; you don't want that because it entirely prevents the Rigidbody from manipulating those values.
Instead of transform.postion += ... first get a reference to the Rigidbody somewhere in your script (best done in an Awake() method):
private Rigidbody _body;
private void Awake() {
_body = GetComponent<Rigidbody>();
}
Then make sure the vector built from your inputs is being applied to the object's "movement," not its position:
Vector3 inputVector = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
// You can multiply this vector by a float to adjust "speed"
_body.ApplyForce(inputVector, ForceMode.VelocityChange);
Finally, you should read up on the different ForceMode options and decide which one fits your preferences: https://docs.unity3d.com/ScriptReference/ForceMode.html
Don't forget this should happen in a FixedUpdate(), not an Update() (all physics operations should be done in FixedUpdate())
As a side note, there is also the possibility your rigidbodies still up moving too quickly and passing through each-other. Even when you're using forces and velocities, this is possible so if your run into this case down the line, investigate Collision Detection Modes. TLDR; they're settings for performance vs accuracy trade-offs.
In my 2D side-scrolling game I move my character using the built-in physics engine by manipulating the rigidbody.velocity.
I would like to add some sort of dodge (roll) ability, where the character moves 3 units in its direction.
Here is the code I used:
void FixedUpdate() {
if (Input.GetKeyDown(KeyCode.A) ) {
Vector2 pos = rb.position;
pos.x -= 5;
rb.MovePosition (pos);
}
}
This method works but the character kind of jumps to the position rather than moving to it (Lerping?) and also doesn't detect collisions despite the body type being dynamic.
Then I tried this:
if (Input.GetKeyDown(KeyCode.A)) {
rb.AddForce(new Vector2(-50, 0));
}
I found the AddForce way isn't accurate at all.
Is there a proper way of doing this?
Maybe you could change the Transform.pos inside Vector2.Lerp to make it look smooth? (Sorry, not enough experience with 2D in unity.)
Just increase rigibody.velocity for a set time. Your chararter object could then play a fitting aniamtion. If The player should not be able to cancle midrole jsut block the controls for that time.
I'm inexperienced with UnityScript and C#, and a solution I can study would be greatly appreciated.
The behavior I want is for Pickups to move in random directions on a terrain, changing direction if they encounter a rigid body or static object.
I tried the script "Wander.cs" available here:
http://wiki.unity3d.com/index.php/Wander
However, when played, the script turns the game object on end, and I cannot correct this. Also, objects tend to pool in corners instead of heading away.
There are two possibilities as far as I can understand your query.
I didn't try but hope it helps.
1- With help of parametric equation of circle i.e.
x=v.t.cos(theta)
y=v.t.sin(theta)
In you case:
x=v.t.cos(theta) + xDistance
z=v.t.sin(theta) + zDistance
where xDistance and zDistance are simple initial position value of your body. These value will not be changed after starting movement (during movement until collision occur).
In Update() apply these equations to your body with constant v and theta and increase t (t++ or t+= 0.1f) by time. When body collides, just retain the current translate (position) value. And start movement again, this time change the value of xDistance and zDistance with current value but only once.
2- With help of iTween. Its a free animation script available at Asset Store
You can use iTween.MoveTo to move body to any given direction (You can assign a random direction as well.). And stop and restart movement upon collision.
I'm using unity to develop my game. I've made a custom swipe gesture by calculating the startPosition and the end Position of the touch. I got the vector direction by subtracting the two positions and debugged it successfully.
But when it comes to applying force to my game object I'm not getting any success after trying a lot.
here's what I'm doing:
swipeDirection = new Vector3(endPos.x - startPos.x,0f, endPos.z - startPos.z);
swipeDirection.Normalize();
Debug.Log("The direction is "+ swipeDirection);
ball.rigidbody.AddForce(swipeDirection * 5);
where ball is just a GameObject. Whenever I run it on my iPhone, the game just gets stuck giving a EXC_BAD_ACCESS code after the first swipe.
So I just tested your code. And it works. This issue you may be having is that those number are pretty small most likely, and you need a LOT of force to move it noticeably. Try changing your 5 to a 1000 or something big so you can definitely see the change. Here is my code, just added to a ball with rigidbody.
void Start ()
{
Vector3 dir = new Vector3 (100f, 0f, 0f);
dir.Normalize ();
this.gameObject.rigidbody.AddForce (dir * 100);
}
almost identical. you just need to make the multiplier big enough to see.
good luck.