koobas.hobune.stream
Camera rotate to look at GameObject from Raycast
Hi guys,
I'm trying to write a C# script that zooms a stationary camera via scroll wheel. I want it so that when a scrolling motion is detected, if the mouse position is over a game object, then the camera rotates towards the game object to look at it and zoom in/out. I'm using Physics.Raycast and having a few problems with accessing the position of the object that is hit for camera.transform.LookAt...
My code so far:
private const int ZoomSpeed = 7;
void Update() {
if(Input.GetAxis("Mouse ScrollWheel") != 0) {
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
RaycastHit hit;
if(Physics.Raycast(ray,out hit, Mathf.Infinity)) {
camera.transform.LookAt (hit.collider.gameObject.position);
//This doesn't work
}
}
var zoomDelta = Input.GetAxis("Mouse ScrollWheel")*ZoomSpeed*Time.deltaTime;
if (zoomDelta > 0 && Camera.main.fieldOfView >10){
Camera.main.fieldOfView--;
}
if (zoomDelta < 0 && Camera.main.fieldOfView <60){
Camera.main.fieldOfView++;
}
}
Any suggestions appreciated!
camera.transform.LookAt (hit.collider.gameObject.transform); worked! (Thank you!)
Follow-up question: I'm wondering if there's a way to get the camera to zoom in/out to any spot that the mouse is over (not necessarily at game object)?
Try using:
camera.transform.LookAt (hit.collider.gameObject.transform);
Ok, here is the final version of the zoom to mouse cursor script via scroll wheel by using Lerp... This script tries to zoom towards/around the mouse cursor so that the mouse is still on the object/area it was initially pointing at (a bit like Google Maps zoom). The Lerping out is still a little buggy, however. Note that the values are tailored to my game and it sometimes shifts a little off the mouse:
Quaternion init;
void Start()
{
init = camera.transform.rotation;
}
void Update () {
if (Input.GetAxis("Mouse ScrollWheel") < 0)
{
camera.transform.rotation = Quaternion.Lerp(init, camera.transform.rotation, .3f);
}
else if (Camera.main.fieldOfView < 50 && Input.GetAxis("Mouse ScrollWheel") < 0)
{
var startR = camera.transform.rotation;
camera.fieldOfView -= 10*Input.GetAxis("Mouse ScrollWheel");
camera.transform.rotation = Quaternion.Lerp(init, startR, .7f);
}
else if (Camera.main.fieldOfView > 7 && Input.GetAxis("Mouse ScrollWheel") > 0)
{
var currentPos = Input.mousePosition;
currentPos.z = 7.3f;
var startR = camera.transform.rotation;
camera.transform.LookAt(camera.ScreenToWorldPoint(currentPos));
camera.fieldOfView -= 10*Input.GetAxis("Mouse ScrollWheel");
camera.transform.rotation = Quaternion.Lerp(transform.rotation, startR,((float)Camera.main.fieldOfView -(float)20*Input.GetAxis("Mouse ScrollWheel")) /((float)Camera.main.fieldOfView) );
}
}
Thanks for all the help!
Regarding your followup question:
You can get the world position under the mouse cursor by using...
worldPos = camera.ScreenPointToRay(mousePosition).GetPoint(distanceInWorldUnits);
As you can see, you need to provide a distance from the camera for the 3D mouse position. This is because the mouse position is 2D screen space and obviously the world space is 3D. A distance of 0 would put your 3D point on the cameras near plane. How to determine the distance you want the 3D point to be is up to you.
