IsometricMap.cs

using UnityEngine;

public class IsometricMap : MonoBehaviour {
    public Texture2D pattern;
    public int pixelToUnit = 100;
    public Vector2 pixelSize = new Vector2(64, 64);
    public Vector2 markerPosition;
    
    void OnDrawGizmosSelected() {
        drawIcon(markerPosition, pixelSize, pixelToUnit);
    }
    
    public void drawIcon(Vector3 markerPosition, Vector2 pixelSize, int pixelToUnit){
        Gizmos.DrawLine(new Vector3(markerPosition.x — (pixelSize.x * 0.5f) / pixelToUnit, markerPosition.y, markerPosition.z),
        new Vector3(markerPosition.x, markerPosition.y + (pixelSize.y * 0.25f) / pixelToUnit, markerPosition.z));
        Gizmos.DrawLine(new Vector3(markerPosition.x — (pixelSize.x * 0.5f) / pixelToUnit, markerPosition.y, markerPosition.z),
        new Vector3(markerPosition.x, markerPosition.y — (pixelSize.y * 0.25f) / pixelToUnit, markerPosition.z));
        Gizmos.DrawLine(new Vector3(markerPosition.x + (pixelSize.x * 0.5f) / pixelToUnit, markerPosition.y, markerPosition.z),
        new Vector3(markerPosition.x, markerPosition.y + (pixelSize.y * 0.25f) / pixelToUnit, markerPosition.z));
        Gizmos.DrawLine(new Vector3(markerPosition.x + (pixelSize.x * 0.5f) / pixelToUnit, markerPosition.y, markerPosition.z),
        new Vector3(markerPosition.x, markerPosition.y — (pixelSize.y * 0.25f) / pixelToUnit, markerPosition.z));
    }
}