UGUI血条跟随

定义常量

public class Content
{
    //当前UI分辨率
    public const float UI_Width = 1366f;
    public const float UI_Height = 768f;

    //手机屏幕大小的二分之一
    public static float screen_width_half = Screen.width / 2;
    public static float screen_height_half = Screen.height / 2;

    //手机屏幕与UI的比率
    public static float screen_width_ratio = UI_Width / Screen.width;
    public static float screen_height_ratio = UI_Height / Screen.height;
}

血条跟随代码实现

using UnityEngine;

public class UI_Follow : MonoBehaviour
{
    public Camera m_camera;
    public Transform m_target;
    public RectTransform m_ui;
    
    private Vector3 position_sp;

    private void Awake()
    {
        if (m_camera == null)
        {
            m_camera = Camera.main;
        }
        if (m_ui == null && transform is RectTransform)
        {
            m_ui = (RectTransform)transform;
        }
    }

    private void LateUpdate()
    {
        if (m_target != null)
        {
            position_sp = m_camera.WorldToScreenPoint(m_target.position);
            Format_Position(ref position_sp);
            m_ui.localPosition = position_sp;
        }
    }

    private void Format_Position(ref Vector3 pos)
    {
        pos.x -= Content.screen_width_half;
        pos.y -= Content.screen_height_half;
        pos.x *= Content.screen_width_ratio;
        pos.y *= Content.screen_height_ratio;
    }
}

UGUI canvas.renderMode需设置为overlay，或camera但camera.projection需改为正交模式【在透视模式下会发生偏移】

实现拖动3D物体

using UnityEngine;

public class DragObject : MonoBehaviour
{
    private Transform m_target;

    private Vector3 pos_target;
    private Vector3 pos_mouse;
    private Vector3 pos_temp;

    private void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            RaycastHit hit;
            if (Physics.Raycast(ray, out hit))
            {
                if (hit.transform.CompareTag("Untagged"))
                {
                    m_target = hit.transform;
                    pos_target = Camera.main.WorldToScreenPoint(m_target.position);
                }
            }
        }
        if (Input.GetMouseButton(0))
        {
            if (m_target != null)
            {
                pos_mouse = Input.mousePosition;
                pos_mouse.z = pos_target.z;
                pos_temp = Camera.main.ScreenToWorldPoint(pos_mouse);
                m_target.position = pos_temp;
            }
        }
        if (Input.GetMouseButtonUp(0))
        {
            if (m_target != null)
            {
                m_target = null;
            }
        }
    }
}