koobas.hobune.stream
Drag and Drop on RTS camera
I have this code to drag and drop 3d objects on a world:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class SpyAI : MonoBehaviour {
Animator anim;
private Vector3 screenPoint;
private Vector3 offset;
// Use this for initialization
void Start () {
anim = gameObject.GetComponent<Animator>();
}
// Update is called once per frame
void Update () {
}
void OnMouseDown()
{
anim.SetBool("drag", true);
screenPoint = Camera.main.WorldToScreenPoint(transform.position);
offset = transform.position - Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenPoint.z));
}
void OnMouseDrag()
{
Vector3 curScreenPoint = new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenPoint.z);
Vector3 curPosition = Camera.main.ScreenToWorldPoint(curScreenPoint) + offset;
transform.position = curPosition;
}
void OnMouseUp()
{
anim.SetBool("drag", false);
anim.SetBool("idle", true);
}
}
The problem is: When im dragging the object, sometimes, depending on the mouse movement it goes undergound How can I make the object to stay above the ground while dragging it?
You're going to have to raycast against the ground to test its elevation and also get the object's y axis extents and add both to your offset. You can also get the ground normal and adjust the rotation of your object to the ground normal if you like.
Use a raycast whose origin is at the dragged objects position that goes downwards. Should look like this:
RaycastHit hit;
Ray ray = new Ray(new Vector3(selectedObjectPos), Vector3.down);
Debug.Log(hit.point.y);
This should print the y coordinate of the collider under the dragged object (selectedObjectPos is the position of the dragged object). You may need to account for the objects size so I believe that you would need to subtract the Collider.bounds.extents.y of the dragged object from the hit.point.y like so: yPos = hit.point.y - selectedObject.GetComponent<Collider>().bounds.extents.y;
Note that this is in C#.
Hope that helps!
Thank you. It worked. Here's the code:
Vector3 curScreenPoint = new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenPoint.z);
Vector3 curPosition = Camera.main.ScreenToWorldPoint(curScreenPoint) + offset;
Ray ray = new Ray(new Vector3(transform.position.x, transform.position.y, transform.position.z), Vector3.down);
float yPos = hit.point.y - collidedrr.bounds.extents.y;
transform.position = new Vector3(curPosition.x, -yPos, curPosition.z);
