unity2d Problem With local positioning of child with rotating parent - unity3d

I am making a game, in which I have clouds that when shot are hidden using sprite masks, the sprite masks are then attached to the cloud via parenting, here is the function that attaches and positions the masks.
public void SpawnGasCloudMask(Transform collisionTransform, Vector2 difference)
{
GasCloudMaskController selectedGasCloudMask = null;
for (int i = 0; i < gasCloudMaskList.Count - 1; i++)
{
if (!gasCloudMaskList[i].gameObject.activeSelf)
{
selectedGasCloudMask = gasCloudMaskList[i];
break;
}
}
if(selectedGasCloudMask == null)
{
selectedGasCloudMask = InstantiateGasCloudMaskController();
}
selectedGasCloudMask.transform.SetParent(collisionTransform);
float angle = collisionTransform.rotation.z;
Vector2 straightPosition = new Vector2(difference.x / collisionTransform.localScale.x, difference.y / collisionTransform.localScale.y);
selectedGasCloudMask.transform.localPosition = straightPosition;
selectedGasCloudMask.gameObject.SetActive(true);
}
enter image description here
This is the result when the cloud is not rotated, However if I rotate it, say 90 degrees.enter image description here
I have tried using RotateAroundLocal, but it is said to be deprecated and I cannot see it having an effect. Obviously what I want is for the masks to be properly attached to the parent based on its rotation, I tried doing some geometry, but solving this remains yet out of my reach. I believe I have to change its local parameter position, I did manage to do it with non parented gameObject, however the local parameter does not offer the RotateAround function. I will appreciate any help.TY.

I found my answer:
selectedGasCloudMask.transform.RotateAround(collisionTransform.position,
-collisionTransform.forward, collisionTransform.eulerAngles.z);
Since the position to which the child attaches to the parent, you need to account for the parent's rotation. The deprecate function that did exactly that was replaced by the generic function, which requires you to understand what is going on.

Related

UNITY How do I change image position?

Below is a snippet of code thats running every update but when I log the local position of the image it still says 0,0,0 when it should be 10,10,10. What am I doing wrong??? Ultimately I am trying to understand how to programmatically move an image around on screen
public partial class MainCanvasSystem : SystemBase
{
protected override void OnUpdate()
{
if (MainGameObjectCanvas.Instance != null && SystemAPI.HasSingleton<MainEntityCanvas>())
{
Entity mainEntityCanvasEntity = SystemAPI.GetSingletonEntity<MainEntityCanvas>();
LocalToWorld targetLocalToWorld = SystemAPI.GetComponent<LocalToWorld>(mainEntityCanvasEntity);
Canvas canvas = MainGameObjectCanvas.Instance;
Image image = canvas.GetComponentInChildren<Image>();
var rect = image.GetComponent<RectTransform>();
rect.localScale.Set(10,10,10);
Debug.Log(rect.localPosition.x);
}
}
}
I think there is general misunderstanding here.
rect.localScale.Set(10,10,10);
does .. nothing!
Transform.localScale is a property and returns a COPY of a Vector3 struct.
You are calling Vector3.Set on it which replaces the values within that Vector3 copy, yes, but then you never actually apply it anywhere.
=> you need to actually set the property!
You rather would do e.g.
rect.locaScale = Vector3.one * 10;
or
rect.localScale = new Vector3(10,10,10);
However, this said, changing a localScale won't change the position at all. The RectTransform.anchoredPosition is probably rather the one to go with.

Best way to create a 2d top down race track procedurally

I am attempting to create a 2d top-down car racing game. This game will have a random road map each time the player plays the game. I have thought about doing this in two different ways: A tilemap, or just generate the roads by placing different prefabs (straight roads, turns, etc). I have decided to go with the prefab route.
The way I believe it should work is to have prefab square "tiles" which have their own colliders set on the edges so I can tell if a player goes off the track in which case they blow up. I would have a MapGenerator Script which will generate an initial random map by keeping track of the last tile placed (including its location and road type: left turn, straight, right, etc). This script will then keep adding onto the road randomly as the player gets closer and closer to the end which makes it an infinite road.
I just want to know if this is just not efficient or if I am thinking of this completely wrong.
Here are a couple of images showing my road tiles which I made in photoshop and then one prefab for a straight road (take note of the colliders on its edges).
A similar game to one I want to make is Sling Drift which I can provide the link if you want. I don't know the policy on adding links to forum chat.
Also, here is my code for the map generator:
//Type of tyle, types are normal (straight road or horizontal road) and turns
public enum MapTileType
{
NORMAL,
N_E,
N_W,
S_E,
S_W
}
//structure for holding the last tile location and its type.
public struct TypedTileLocation
{
public TypedTileLocation(Vector2 pos, MapTileType tyleType)
{
m_tileType = tyleType;
m_position = pos;
}
public Vector2 m_position;
public MapTileType m_tileType;
}
public class MapGenerator : MonoBehaviour
{
//Map Tiles
public GameObject m_roadTile;
public GameObject m_turnNorthWestTile;
//holds all the tiles made in the game
private List<GameObject> m_allTiles;
//Map Tile Widths and Height
private float m_roadTileWidth, m_roadTileHeight;
//Used for generating next tile
TypedTileLocation m_lastTilePlaced;
private void Awake()
{
//store the initial beginning tile location (0,0)
m_lastTilePlaced = new TypedTileLocation(new Vector2(0,0), MapTileType.NORMAL);
//set height and width of tiles
m_roadTileWidth = m_roadTile.GetComponent<Renderer>().bounds.size.x;
m_roadTileHeight = m_roadTile.GetComponent<Renderer>().bounds.size.y;
m_allTiles = new List<GameObject>();
}
// Start is called before the first frame update
void Start()
{
SetupMap();
}
void SetupMap()
{
//starting at the beginning, just put a few tiles in straight before any turns occur
for (int i = 0; i < 6; ++i)
{
GameObject newTempTile = Instantiate(m_roadTile, new Vector2(0, m_roadTileHeight * i), Quaternion.identity);
m_lastTilePlaced.m_tileType = MapTileType.NORMAL;
m_lastTilePlaced.m_position.x = newTempTile.transform.position.x;
m_lastTilePlaced.m_position.y = newTempTile.transform.position.y;
m_allTiles.Add(newTempTile);
}
//now lets create a starter map of 100 road tiles (including turns and straigt-aways)
for (int i = 0; i < 100; ++i)
{
//first check if its time to create a turn. Maybe I'll randomly choose to either create a turn or not here
//draw either turn or straight road, if the tile was a turn decide which direction we are now going (N, W, E, S).
//this helps us determine which turns we can take next
//repeat this process.
}
}
void GenerateMoreMap()
{
//this will generate more map onto the already existing road and then will delete some of the others
}
// Update is called once per frame
void Update()
{
}
private void OnDrawGizmos()
{
}
}
Thanks!
Have you tried splines? They let you make curvy paths like race tracks easily. If not, here is a video that might help: https://www.youtube.com/watch?v=7j_BNf9s0jM.

Instantiate GameObjects and change Material when it hits on the ground

There is a code for instantiate cube into the list and change a Material of each clone when it hits on the ground
The following code works but not in Real-Time. Update function works like a Start function for a Foreach method
How to get a value of item.transform.position.y in the Update function Real-Time?
public GameObject cubePrefab;
public Material RedMat;
public float GroudLevel = 0.5f;
void Update()
{
if (Input.GetMouseButtonDown(0))
{
List<GameObject> cloneList = new List<GameObject>();
//instantiate clones into the list
for (int i = 0; i < 10; i++)
{
var clone = Instantiate (cubePrefab,new Vector3(Random.Range(-3f, 3f),
Random.Range(4f, 10.5f),Random.Range(-3f, 3f)), Quaternion.identity);
cloneList.Add(clone);
}
//if clone is grounded change a Material for each clone
foreach (var item in cloneList)
{
//Debug.Log(item.transform.position.y);
//check if clone is on the ground
if(item.transform.position.y < GroudLevel)
{
item.GetComponent<Renderer>().material = RedMat;
}
}
}
}
There is a screenshot for a GroudLevel = 7
The reason this function isn't working is because the pivot (transform.position) of your item is always in the center of the object. This isn't something you can change in Unity (nor would you necessarily want to).
On top of this, you're checking if the item is under the ground, and not on it when you use < insteaad of <=, because the position needs to be less than groundLevel to return true.
There are several solutions here.
The simplest would involve moving all of this logic to an OnCollisionEnter or OnTriggerEnter method. For more information on this, check the Unity documentation.
Another solution would be to find a way tthe size of the object, divide it by two, and check if
item.transform.position - halfSize <= groundLevel;
This seems really cumbersome and overly complex, however. You'd be better off using Unity's built-in collision system, unless you have a reason not to.

Placing randomly sized objects side by side unity 2D

I am attempting to instantiate differently shaped prefabs next to eachother. I have a folder full of differently sized objects that allow for me to string them together randomly to create a 2D endless runner. My issue is that all the answers online about placing objects beside eachother don't work when different sized objects are used. Here is the code I am using to instantiate the sections. It works when it only randomly selects similar sized objects. When the selected prefab is a different length it leaves either a gap between, or overlaps, the previous object.
for(int i = 0; i < activeSectionsAtOnce; i++)
{
int index = Random.Range(0, sectionPrefabs.Length);
GameObject currentOb = sectionPrefabs[index];
Vector2 position = new Vector2();
if(activeSections.Count == 0)
{
//set a (0, 0) position for first object
position = Vector2.zero;
}
else
{
//get most recently placed object from list
GameObject lastOb = activeSections[activeSections.Count - 1];
//my attempt at getting bounds for the last object and for the next prefab that will be used
Bounds lasObbounds = new Bounds(lastOb.transform.position, Vector2.zero);
Bounds currentBounds = new Bounds(currentOb.transform.position, Vector2.zero);
//Include child objects(all have sprite renderers)
foreach (Renderer r in lastOb.GetComponentsInChildren<Renderer>())
{
lasObbounds.Encapsulate(r.bounds);
}
foreach (Renderer rend in currentOb.GetComponentsInChildren<Renderer>())
{
currentBounds.Encapsulate(rend.bounds);
}
//position object will be instantiated at
position.x = lastOb.transform.position.x + (lasObbounds.size.x / 2) + (currentBounds.size.x/2);
}
//instantiate at selected position
activeSections.Add(
Instantiate(currentOb, position, Quaternion.identity)
);
}
This is in the start method. I'm not sure if the problem is how I'm creating the bounds, or how im mathematicaly creating the x coordinate. This is the expected result that happens when I use same sized prefabs. This is what happens with different prefabs
The shorter protrusion from the first object should be cleanly between the other two without a gap.
Here's an image of one prefab
Thanks for any advice

Moving something rotated on a custom pivot Unity

I've created an arm with a custom pivot in Unity which is essentially supposed to point wherever the mouse is pointing, regardless of the orientation of the player. Now, this arm looks weird when pointed to the side opposite the one it was drawn at, so I use SpriteRenderer.flipY = true to flip the sprite and make it look normal. I also have a weapon at the end of the arm, which is mostly fine as well. Now the problem is that I have a "FirePoint" at the end of the barrel of the weapon, and when the sprite gets flipped the position of it doesn't change, which affects particles and shooting position. Essentially, all that has to happen is that the Y position of the FirePoint needs to become negative, but Unity seems to think that I want the position change to be global, whereas I just want it to be local so that it can work with whatever rotation the arm is at. I've attempted this:
if (rotZ > 40 || rotZ < -40) {
rend.flipY = true;
firePoint.position = new Vector3(firePoint.position.x, firePoint.position.y * -1, firePoint.position.z);
} else {
rend.flipY = false;
firePoint.position = new Vector3(firePoint.position.x, firePoint.position.y * -1, firePoint.position.z);
}
But this works on a global basis rather than the local one that I need. Any help would be much appreciated, and I hope that I've provided enough information for this to reach a conclusive result. Please notify me should you need anything more. Thank you in advance, and have a nice day!
You can use RotateAround() to get desired behaviour instead of flipping stuff around. Here is sample code:
public class ExampleClass : MonoBehaviour
{
public Transform pivotTransform; // need to assign in inspector
void Update()
{
transform.RotateAround(pivotTransform.position, Vector3.up, 20 * Time.deltaTime);
}
}