Develop Reference

How to instantiate object on correct position?

I have one really big issue with my game . When i try press play when he spawn first prefab everything is correct X position is -0.604f , z is -1.49f..But when i spawn second object the second and the third object get spawned on wrong position of x and z.
On the second object X position is not good ( in this case second Z position of object is -1.208 and i need here same value as before -0.604) I really don't know why this happens and I don't know how i can change Z position when i spawn third object in other side so if first two objects are on right and left and when i spawn third object he get Z position of -4.968 which is not correct because I need on third position on Z = -1.655984 and i am getting on third object z position of ~-5f.
Here is my code to spawn objects..
public class StackPiecesSpawner : Singleton<StackPiecesSpawner> {
public GameObject stackPrefab;
[SerializeField] public Transform StackPieceSpawnPoint;
[SerializeField] public float PieceSpawnSize = 0.1f;
[SerializeField] public float PieceSpawnWidth = 1.0f;
[SerializeField] private float speed = 1f;
public Vector3 OriginalSpawnPointPosition;
protected override void Awake()
{
base.Awake();
OriginalSpawnPointPosition = StackPieceSpawnPoint.position;
}
public void SpawnNextStackPiece()
{
//StackPieceSpawnPoint.position += new Vector3(0f,PieceSpawnSize,0f);
StackPieceSpawnPoint.position += new Vector3(0.604f, 0.1f, -1.656f);
//GameObject go = GameObject.CreatePrimitive(PrimitiveType.Cube);
GameObject go = GameObject.Instantiate(stackPrefab);
//go.transform.localScale = new Vector3(PieceSpawnWidth,PieceSpawnSize,PieceSpawnWidth);
go.transform.localScale = new Vector3(0.4f, 0.4f,0.05f);
go.transform.position = nextSpawnPosition();
go.AddComponent<Rigidbody>();
go.GetComponent<Rigidbody>().isKinematic = true;
go.AddComponent<StackPiece>();
go.transform.parent = transform;
go.transform.name = "StackPiece_" + (StackPiecesManager.StackPieces.Count + 1);
StackPiece piece = go.GetComponent<StackPiece>();
piece.TargetTransform = StackPieceSpawnPoint;
piece.Speed = speed;
StackPiecesManager.Instance.AddNewPiece(piece);
}
private Vector3 nextSpawnPosition()
{
System.Random rnd = new System.Random();
int num = rnd.Next(0, 100);
Vector3 modifier = new Vector3();
modifier = num < 50 ? Vector3.back : Vector3.left;
modifier *= StackPiecesManager.Instance.SpawnDistance;
Vector3 returned = (StackPieceSpawnPoint.position - modifier) + Vector3.up * (StackPiecesManager.Instance.ExtraHeight);
// returned = (StackPieceSpawnPoint.position) + Vector3.up * (StackPiecesManager.Instance.ExtraHeight);
return returned;
}
public void Reset()
{
StackPieceSpawnPoint.position = OriginalSpawnPointPosition;
}
}

I cannot completely answer this question as not all the code and context is available, however, I could maybe point you in the right direction.
Parent-child relationship
In the SpawnNextStackPiece you instantiate a prefab and have its current parent transform equal the current transform(of the object this script is attached to), check if the transform you're changing the parent to is shifting each time a prefab is instantiated. I tend to avoid changing parent transforms, I usually try to attach it to different parents and change the actual objects offset not the parents, it can be easier to manage. I suspect go.transform.parent = transform; is causing a problem.
Diagnosing the problem through zeroing out values
Try forcefully making the z-axis 0 so you can see how much it is getting offset by each time it spawns, that may make diagnosing the problem much easier. Do this with StackPieceSpawnPoint.position = new Vector3(0.604f, 0.1f,0f);

OnMouseOver() and OnMouseExit()

I am trying to instantiate a number of planes to use as my terrain and give them OnMouseOver() to change them to some color and OnMouseExit() to change them back to the original color.
I attached a plane instantiation script to the main camera to generate the plane prefab and a mouse event script to the plane prefab. I get them all instantiated and the events pass to them, but in-game the mouse events are being applied to either long strips of planes, an entire quadrant, or a random single plane not at the location of the mouse cursor.
I made a new material and applied it to the place prior to turning it into a prefab to replace the standard material set upon creation of the plane.
I have started attempting to use the mouse position to apply the color change to the plane at the current mouse position with Physics.CheckSphere, but I don't fully understand how to tell specifically what gameObject is at a specific position.
public class TerrainGeneration : MonoBehaviour {
[SerializeField]
private Transform groundTile;
private Vector3 row;
private int max = 10;
// Use this for initialization
void Start () {
for ( int i = 0; i <= max; i++)
{
for (int x = 0; x <= max; x++) {
row = new Vector3(i, 0, x);
Instantiate(groundTile, row, Quaternion.identity);
}
}
}
}
public class MouseEvents : MonoBehaviour {
private Color isTargeted;
private Color notTargeted;
private MeshRenderer groundTileMeshRenderer;
private Vector3 mousePosition;
private float mouseX;
private float mouseY;
void Start () {
groundTileMeshRenderer = gameObject.GetComponent<MeshRenderer>();
isTargeted = Color.cyan;
notTargeted = groundTileMeshRenderer.material.color;
}
void Update()
{
mouseX = Mathf.RoundToInt(Input.GetAxis("Mouse X"));
mouseY = Mathf.RoundToInt(Input.GetAxis("Mouse Y"));
mousePosition = new Vector3(mouseX, 0, mouseY);
if (Physics.CheckSphere(mousePosition, 1))
{
**//Get the specific gameObject located at the current mouse position
//Set the gameObject as the target for the color change**
}
}
void OnMouseOver()
{
groundTileMeshRenderer.material.color = isTargeted;
}
void OnMouseExit()
{
groundTileMeshRenderer.material.color = notTargeted;
}
}

So, I found out what the answer is thanks to the Unity forums. My error was in the instantiation transform script. Because I was using the plane primitive 3d object I was not accounting for the size of the plane correctly. The following code snippet for instantiation of each row removes the overlapping that was occurring as the planes are too large to simply place at (0,0,0), (0,0,1), (0,0,2) for example.
row = new Vector3(i * 10, 0, x * 10);
Instantiate(groundTile, row, Quaternion.identity);

tag your gameObjects as necessary and then you can identify them.
If you do, then you can use them like so (purely for example):
public virtual void OnTriggerEnter(Collider other)
{
if (other.gameObject.tag == "planeA")
{
//do something
}
}

How to draw latitude/longitude lines on the surface of a Sphere in Unity 3D?

I'm a beginner of Unity 3D. And I'm trying to create a globe with Unity 3D as shown below. I created a Sphere game object on a scene and set the radius as 640. Then, I want to draw latitude/longitude lines (every 10 degree) on the surface of this Sphere in C# script.
I tried to draw each lat/long line by using LineRender, but did not get it work.
My code:
public class EarthController : MonoBehaviour {
private float _radius = 0;
// Use this for initialization
void Start () {
_radius = gameObject.transform.localScale.x;
DrawLatLongLines();
}
// Update is called once per frame
void Update()
{
}
private void DrawLatLongLines()
{
float thetaStep = 0.0001F;
int size = (int)((2.0 * Mathf.PI) / thetaStep);
// draw lat lines
for (int latDeg = 0; latDeg < 90; latDeg += 10)
{
// throw error here.
// seems I cannot add more than one component per type
LineRenderer latLineNorth = gameObject.AddComponent<LineRenderer>();
latLineNorth.startColor = new Color(255, 0, 0);
latLineNorth.endColor = latLineNorth.startColor;
latLineNorth.startWidth = 0.2F;
latLineNorth.endWidth = 0.2F;
latLineNorth.positionCount = size;
LineRenderer latLineSouth = Object.Instantiate<LineRenderer>(latLineNorth);
float theta = 0;
var r = _radius * Mathf.Cos(Mathf.Deg2Rad * latDeg);
var z = _radius * Mathf.Sin(Mathf.Deg2Rad * latDeg);
for (int i = 0; i < size; i++)
{
var x = r * Mathf.Sin(theta);
var y = r * Mathf.Cos(theta);
Vector3 pos = new Vector3(x, y, z);
latLineNorth.SetPosition(i, pos);
pos.z = -z;
latLineSouth.SetPosition(i, pos);
theta += thetaStep;
}
}
}
}
What's the correct way to do this?
I don't want to write custom shader (if possible) since I know nothing about it.

The usual way to customize the way 3d objects look is to use shaders.
In your case, you would need a wireframe shader, and if you want control on the number of lines, then you might have to write it yourself.
Another solution is to use a texture. In unity, you will have many default materials that will apply a texture on your object. You can apply an image texture that contains your lines.
If you don't want a texture and really just the lines, you could use the line renderer. LineRenderer doesn't need a 3D object to work. You just give it a number of points and it is going to link them with a line.
Here is how I would do it:
Create an object with a line renderer and enter points that create a
circle (You can do it dynamically in c# or manually in the editor on
the line renderer).
Store this as a prefab (optional) and duplicate it in your scene
(copy paste. Each copy draws a new line
Just be modifying the rotation, scale and position of your lines you
can recreate a sphere
If your question is "What is the equation of a circle so I can find the proper x and y coord?" here is a short idea to compute x and y coord
for(int i =0; i< nbPointsOnTheCircle; ++i)
{
var x = Mathf.Cos(nbPointsOnTheCircle / 360);
var y = Mathf.Sin(nbPointsOnTheCircle / 360);
}
If your question is "How to assign points on the line renderer dynamicaly with Unity?" here is a short example:
public class Circle : MonoBehavior
{
private void Start()
{
Vector3[] circlePoints = computePoints(); // a function that compute points of a circle
var lineRenderer = GetComponent<LineRenderer>();
linerenderer.Positions = circlePoints;
}
}
EDIT
You can only have one per object. This is why the example above only draws one circle. You already have a earth controller, but this controller can't add many LineRenderes to itself. Instead, the idea would be that the earth object has a script that does the something like following:
private void Start()
{
for(int i=0; i<nbLines;++i)
{
GameObject go = new GameObject();
go.AddComponent<LineRenderer>();
go.AddCOmponent<Circle>();
go.transform.SetParent = transform;
go.name = "Circle" + i;
}
}
Then you will see several objects created in you scene, each having exactly one LineRenderer and one Circle component
From there you should be able to do what you want (for instance, pass parameters to the Circle so each Circle is a bit different)

Unity 2017.3: transform.position assign attempt is not valid. Input position is { -infinity, 0,0 }

I've been trying to build a raycast controller for a 2D game, and have followed some tutorial series to help me better understand how this is done. So far everything has been going well, and I've actually followed several tutorials on this topic to completion without issue.
However, while using this current character controller I am getting a slew of errors on play, even with no compiler errors present. I have never seen this error, and have not been able to find a solution online about how to fix it. Basically my character disappears on play (I assume its being moved infinitely to the left).
I get two errors: "transform.position assign attempt is not valid. Input position is { -infinity, 0,0 }," and "Invalid world AABB. Object is too large or too far away from origin."
The error occurs on lines 90:
public void LateUpdate()
{
Move(Velocity * Time.deltaTime);
}
and 126:
characterTransform.Translate(deltaMovement, Space.World);
I have tried a bunch of different things, including changing my character's scale, changing Vector2s to Vector3s, removing Space.World, and calling transform.Translate directly (as opposed to using my characterTransform). Nothing seems to work, and for some reason my camera gives me an error sometimes too, though it is hard to reproduce. If I remove either line of code I get no errors, but obviously my character cannot move.
Screenshot of the errors: https://imgur.com/a/24KIN
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
/// <summary>
/// Handles the character movement with raycasts
/// </summary>
public class CharacterController2D : MonoBehaviour {
//Defines the number of rays
private const int totalHorizontalRays = 8;
private const int totalVeritcalRays = 4;
private RaycastOrigins raycastOrigins; //References the RayCastOrigins struct
private const float skinWidth = .02f; //Defines the skin width of the rays, which places the origin point of the rays slightly inside the character's box collider
private static readonly float slopeLimitTanget = Mathf.Tan(75f * Mathf.Deg2Rad);
public LayerMask platformMask; //Defines the layermask that will be used to determine how different layers interact with the character
public ControllerParameters2D defaultParameters; //References the ControllerParameters2D class
public ControllerState2D State { get; private set; } //References the ControllerState2D class
public ControllerParameters2D Parameters { get { return overrideParameters ?? defaultParameters; } } //Returns updated parameters, or default parameters if overrideParameters is null
public Vector2 Velocity { get { return velocity; } } //Defines the character's velocity
public bool CanJump { get { return false; } } //Defines whether or not the character can jump
public bool HandleCollisions { get; set; } //Defines whether or not the character needs to handle collisions (because it is colliding with something)
private Vector2 velocity; //The field for the Velocity property
private BoxCollider2D boxCollider; //References the box collider on the character
private ControllerParameters2D overrideParameters; //References the updated parameters (that is, the updated parameters, not the default ones)
private Transform characterTransform; //References the character's transform
private Vector3 localScale; //References the character's scale
//The distance between raycasts
private float horizontalDistanceBetweenRays;
private float verticalDistanceBetweenRays;
private struct RaycastOrigins //Stores the value types that define where the raycasts are created on the box collider
{
public Vector2 topLeft, topRight; //Creates variables to define the upper position of the raycasts
public Vector2 bottomLeft, bottomRight; //Creates variables to define the lower position of the raycasts
}
public void Awake()
{
State = new ControllerState2D(); //Accesses the ControllerState2D script
boxCollider = GetComponent<BoxCollider2D>(); //Accesses the character's box collider
characterTransform = transform; //Accesses the character's transform
localScale = transform.localScale; //Accesses the character's scale
//Gets the ray spacing
horizontalDistanceBetweenRays = CalculateHorizontalRaySpacing();
verticalDistanceBetweenRays = CalculateVerticalRaySpacing();
}
public void Start()
{
}
public void AddForce(Vector2 force)
{
velocity += force;
}
public void SetForce(Vector2 force)
{
velocity = force;
}
public void SetHorizontalForce(float x)
{
velocity.x = x;
}
public void SetVerticalForce(float y)
{
velocity.y = y;
}
public void Jump()
{
}
public void LateUpdate()
{
Move(Velocity * Time.deltaTime); //Moves the character per its velocity, scaled by time
}
public void OnTriggerEnter2D(Collider2D other)
{
}
public void OnTriggerExit2D(Collider2D other)
{
}
private void Move(Vector2 deltaMovement)
{
var wasGrounded = State.IsCollidingBelow; //Keeps track of whether or not the character is grounded
State.Reset(); //Resets the state
if (HandleCollisions) //If the character should handle collisions
{
HandlePlatforms();
CalculateRaycastOrigins();
if (deltaMovement.y < 0 && wasGrounded) //If the character is moving down, and was previously grounded...
{
ClimbDownSlope(ref deltaMovement);
}
if (Mathf.Abs(deltaMovement.x) > .001f) //If the character is moving left or right...
{
MoveHorizontally(ref deltaMovement);
}
MoveVertically(ref deltaMovement); //Calls the MoveVertically method always, since the character always has the force of gravity enacted on it
}
characterTransform.Translate(deltaMovement, Space.World); //Moves the character after all potential movement scenarios have been accounted for
if (Time.deltaTime > 0)
{
velocity = deltaMovement / Time.deltaTime; //Sets the current velocity equal to the change in movement
}
//Clamps the velocity to the maximum x and y velocity defined in Parameters
velocity.x = Mathf.Min(velocity.x, Parameters.maxVelocity.x);
velocity.y = Mathf.Min(velocity.y, Parameters.maxVelocity.y);
if (State.IsMovingUpSlope) //If the character is moving up a slope...
{
velocity.y = 0;
}
}
private void MoveHorizontally(ref Vector2 deltaMovement)
{
var isGoingRight = deltaMovement.x > 0; //Defines if the character is going right
var rayDistance = Mathf.Abs(deltaMovement.x) + skinWidth; //Defines the distance of the raycasts
var rayDirection = isGoingRight ? Vector2.right : -Vector2.right; //Defines in which direction the rays will shoot, depdending on character direction
var rayOrigin = isGoingRight ? raycastOrigins.bottomRight : raycastOrigins.bottomLeft; //Defines the current ray origin
for (var i = 0; i < totalHorizontalRays; i++) //Loops through each of the 8 horizontal rays
{
var rayVector = new Vector2(rayOrigin.x, rayOrigin.y + (i * verticalDistanceBetweenRays)); //Builds the rays (stacking them up with each ray that is added)
Debug.DrawRay(rayVector, rayDirection * rayDistance, Color.red);
var rayCastHit = Physics2D.Raycast(rayVector, rayDirection, rayDistance, platformMask); //Actually draws the rays
if (!rayCastHit) //If the raycast hits something... (rayCastHit is true)
{
continue;
}
if (i == 0 && ClimbUpSlope(ref deltaMovement, Vector2.Angle(rayCastHit.normal, Vector2.up), isGoingRight)) //If the character is now climbing a slope...
{
break;
}
deltaMovement.x = rayCastHit.point.x - rayVector.x; //Clamps horizontal movement based on ray collision
rayDistance = Mathf.Abs(deltaMovement.x); //Clamps the ray distance based on how far the character is allowed to move (i.e. ensures the rays end at walls)
if (isGoingRight) //If the character is going right...
{
deltaMovement.x -= skinWidth; //Ensures that the character moves with the correct value (otherwise would be able to move slightly more based on skinWidth value)
State.IsCollidingRight = true;
}
else //If the character is going left...
{
deltaMovement.x += skinWidth;
State.IsCollidingLeft = true;
}
if (rayDistance < skinWidth + .0001f) //If a collision gets bugged for some reason...
{
break;
}
}
}
private void MoveVertically(ref Vector2 deltaMovement)
{
}
private void ClimbDownSlope(ref Vector2 deltaMovement)
{
}
private bool ClimbUpSlope(ref Vector2 deltaMovement, float angle, bool isGoingRight)
{
return false;
}
private void HandlePlatforms()
{
}
private float CalculateHorizontalRaySpacing()
{
Bounds bounds = boxCollider.bounds; //Sets the 'bounds' variable equal to the bounds of the box collider on the game object
bounds.Expand(skinWidth * -2); //Enforces the skinWidth variable
return bounds.size.y / (totalHorizontalRays - 1); //Ensures that all rays are spaced evenly on the sides of the box collider
}
private float CalculateVerticalRaySpacing()
{
Bounds bounds = boxCollider.bounds; //Sets the 'bounds' variable equal to the bounds of the box collider on the game object
bounds.Expand(skinWidth * -2); //Enforces the skinWidth variable
return bounds.size.x / (totalVeritcalRays - 1); //Ensures that all rays are spaced evenly on the bottom and top of the box collider
}
private void CalculateRaycastOrigins()
{
Bounds bounds = boxCollider.bounds; //Sets the 'bounds' variable equal to the bounds of the box collider on the game object
bounds.Expand(skinWidth * -2); //Enforces the skinWidth variable
//Creates the starting positions of the raycasts
raycastOrigins.bottomLeft = new Vector2(bounds.min.x, bounds.min.y);
raycastOrigins.bottomRight = new Vector2(bounds.max.x, bounds.min.y);
raycastOrigins.topLeft = new Vector2(bounds.min.x, bounds.max.y);
raycastOrigins.topRight = new Vector2(bounds.max.x, bounds.max.y);
}
}

After doing some research, it seems this is a bug that can sometimes occur.
Not sure why I didn't try this sooner, but reinstalling Unity fixed all the issues...

Memory overload on for loop

I am making an object spawn script in which on the start of the script the spawning function is called and in it is a for loop which creates an object each iteration. It first picks a random X position for it and then checks if it is in a range of another prefabs coordinates so they don't spawn too close or worse, one in each other. If it is in the same coordinates as another prefab it will return 0 and this same goes out for the Z axis too. It also picks a random Y axis rotation so it doesn't all face the same direction. After this it spawns the prefab and sets it's coordinates and rotation after which it check if the coordinates in the X or Z axis are 0, and if any of those two are 0 it goes back one iteration and the last object to be spawned is destroyed so it doesn't flood. This works perfectly but when you want to set it to spawn too much objects it floods the RAM because there is nowhere to spawn more objects. I tried finding the highest X position and highest Z position and multiplying them, and setting them both to positive, and then dividing them by the space between the prefabs but this doesn't work as it sets it to a really really high number. How would you fix this?
Script:
using UnityEngine;
using System.Collections;
public class PrefabSpawner : MonoBehaviour {
public int amountOfPrefabs;
public int maxAmountOfPrefabs;
private int currentSpawnedPrefab;
public float spaceBetweenPrefabs;
private float positionX;
private float positionZ;
private float maxPositionX;
private float maxPositionZ;
private float multipliedPosXZ;
private bool previousSpawnHadZero;
public GameObject prefab;
private GameObject point1;
private GameObject point2;
private GameObject currentSpawn;
private Vector2[] positions;
void Start () {
currentSpawnedPrefab = 0;
previousSpawnHadZero = false;
point1 = gameObject.transform.GetChild (0).gameObject;
point2 = gameObject.transform.GetChild (1).gameObject;
if (point1.transform.position.x > point2.transform.position.x)
maxPositionX = point1.transform.position.x;
else
maxPositionX = point2.transform.position.x;
if (point1.transform.position.z > point2.transform.position.z)
maxPositionZ = point1.transform.position.z;
else
maxPositionZ = point2.transform.position.z;
multipliedPosXZ = maxPositionX * maxPositionZ;
if (multipliedPosXZ < 0)
multipliedPosXZ += multipliedPosXZ + multipliedPosXZ;
maxAmountOfPrefabs = Mathf.FloorToInt (multipliedPosXZ / spaceBetweenPrefabs);
if (amountOfPrefabs > maxAmountOfPrefabs)
amountOfPrefabs = maxAmountOfPrefabs;
point1.GetComponent<MeshRenderer> ().enabled = false;
point2.GetComponent<MeshRenderer> ().enabled = false;
gameObject.GetComponent<MeshRenderer> ().enabled = false;
positions = new Vector2[amountOfPrefabs];
SpawnPrefabs (amountOfPrefabs);
}
void SpawnPrefabs (int amount) {
for (int i = 0; i < amount; i++) {
if(previousSpawnHadZero)
i -= 1;
currentSpawn = (GameObject)Instantiate (prefab);
positionX = GetRandomPositionX ();
positionZ = GetRandomPositionZ ();
currentSpawn.transform.position = new Vector3 (positionX, this.transform.position.y + currentSpawn.transform.localScale.y, positionZ);
currentSpawnedPrefab += 1;
if (positionX == 0 || positionZ == 0) {
previousSpawnHadZero = true;
currentSpawnedPrefab -= 1;
Destroy (currentSpawn);
}
if (positionX != 0 && positionZ != 0) {
previousSpawnHadZero = false;
positionX = 0;
positionZ = 0;
}
}
}
IEnumerator Pause () {
yield return null;
}
float GetRandomPositionX () {
//Finds a random position for the X axis and then checks it and returns either 0 if the position is taken or the position if not
}
float GetRandomPositionZ () {
//Finds a random position for the Z axis and then checks it and returns either 0 if the position is taken or the position if not
}
bool CheckPositionAvailable (float pos, int axis) {
//Checks if the position is available.
}
}

Code is really long to debug but the problem is clearly visible and is from the SpawnPrefabs function. Currently, when you instantiate a prefab, you check if the generated position is 0. If 0, you subtract 1 from the i in the for loop then destroy the instantiated object and then start the for loop again from the current loop-1.
So the combination of Instantiate, Destroy and repeating it over again in the for loop is causing the memory issue.
What to do:
You have to re-write the whole function and this will require modification in your whole code too. Do not instantiate and destroy object in that loop unless when needed.
1.In the Start() function, create one prefab.
2.Make it to be invisible in the scene by disabling its mesh/sprite renderer.
3.Use that prefab in the for loop to check if the generated position is valid. If it is valid, you can now create/instantiate an object in the loop.
This prevents instantiating and destroying objects in the loop when you only create objects when if (positionX != 0 && positionZ != 0) .