Hi gang,
First post so let me know if theres any ediquette rules or otherwise I’m breaking 
Details of this are:
- This is all based on the below tutorial for a non world space UI inventory.
- I’m working on a 3d game with a first person perspective at the moment.
- I’m trying to make a grid system that can be accessed anywhere in the world space.
- There’s multiple grids, they can be detected via onpointerenter
The problem
- Currently this script only works when inputs are coming from a 0,0 degree angles (so the camera is facing a specific angle). Anything else and the results are inaccurate
- I think this is due to the script this is based on not being designed for 3d use. The mouseposition coordinates can get very high/low and thats one obvious cause to the inaccurate grid results
The code
public Vector2Int GetTileGridPosition (Vector2 mousePosition)
{
var pos = mousePosition;
Vector3 output = Vector2.zero;
RectTransformUtility.ScreenPointToWorldPointInRectangle(this.rectTransform,pos,cam,out output);
positionOnTheGrid.x = (output.x - ((rectTransform.position.x ) ));
positionOnTheGrid.y = rectTransform.position.y - output.y;
tileGridPosition.x = (int)Mathf.Abs((positionOnTheGrid.x/tileSizeWidth));
tileGridPosition.y = (int)(positionOnTheGrid.y/tileSizeHeight);
return tileGridPosition;
}
Example of method call
Debug.Log("This tha" + selectedItemGrid.GetTileGridPosition(Input.mousePosition));
Example of the script that detects grid via mouse enter
private void Awake()
{
Cursor.visible = true;
inventoryController = FindObjectOfType(typeof(InventoryController)) as InventoryController;
itemGrid = GetComponent<ItemGrid>();
}
public void OnPointerEnter(PointerEventData eventData)
{
inventoryController.selectedItemGrid = itemGrid;
}
public void OnPointerExit(PointerEventData eventData)
{
inventoryController.selectedItemGrid = null;
}
Example of a full script (attached to camera) calling on mouse position in grid
{
if (selectedItemGrid == null) { return;}
Debug.Log("Testing position " + selectedItemGrid.GetTileGridPosition(Input.mousePosition));
if (Input.GetMouseButtonDown(0))
{
Vector2Int tileGridPosition = selectedItemGrid.GetTileGridPosition(Input.mousePosition);
if (itemModel == null)
{
itemModel = selectedItemGrid.PickUpItem( tileGridPosition.x, tileGridPosition.y);
}
else{
bool complete = selectedItemGrid.PlaceItem(itemModel, tileGridPosition.x, tileGridPosition.y);
if (complete)
{
itemModel = null;
}
}
}
}
Gamespace Examples
I also attached two examples of this happening in unity testing.
Attached are two images, rotation on the Y axis is the reference for both.
In the incorrect one the character is facing 90 degrees on the y axis and when the mouse enters square 4,4 it returns 0,3.
In the correct one the character is facing 20 degrees on the Y axis and the mouse when entered on the same 4, 4 square returns 3,3. This is the intended interaction.
