Picking / Dragging Objects with Mouse

First problem: I'm setting a fixed Z to the mouse position and i want the object to stands in its original z axis. Any insights about that? I've tried some other things but it didnt work properly.

// ... (snip) ...
if (Physics.Raycast(ray, hit))           
    hit.transform.position = ray.origin + ray.direction * 10;
// ... (snip) ...

Second problem: I want the first click to doesnt move the object, the first just to select and after the click you move the mouse and then the object comes along. This way, any click the objects moves a little.

I didn't know if you want to drag while holding down the mouse button or if you want to toggle dragging with a mouse click. I provide a useToggleDrag to switch between the two styles.

var grabbed : Transform; var grabDistance : float = 10.0f;

var useToggleDrag : boolean; // Didn't know which style you prefer.

function Update () { if (useToggleDrag) UpdateToggleDrag(); else UpdateHoldDrag(); }

// Toggles drag with mouse click function UpdateToggleDrag () { if (Input.GetMouseButtonDown(0)) Grab(); else if (grabbed) Drag(); }

// Drags when user holds down button function UpdateHoldDrag () { if (Input.GetMouseButton(0)) if (grabbed) Drag(); else Grab(); else grabbed = null; }

function Grab() { if (grabbed) grabbed = null; else { var hit : RaycastHit; var ray : Ray = Camera.main.ScreenPointToRay(Input.mousePosition); if (Physics.Raycast(ray, hit))
grabbed = hit.transform; } }

function Drag() { var ray : Ray = Camera.main.ScreenPointToRay(Input.mousePosition); var position : Vector3 = transform.position + transform.forward grabDistance; var plane : Plane = new Plane(-transform.forward, position); var distance : float; if (plane.Raycast(ray, distance)) { grabbed.position = ray.origin + ray.direction distance; grabbed.rotation = transform.rotation; } }

// This drag wasn't like the OP wanted. function OldDrag() { var ray : Ray = Camera.main.ScreenPointToRay(Input.mousePosition); grabbed.position = ray.origin + ray.direction * grabDistance; }

I've discovered something that keeps the original Z on the object.

I've noticed that on the mousePos.z i have tu put the difference between my camera.z and my object.z and it works

Like this:

var desiredZ: float = Mathf.Abs(Utils.Round((Camera.main.transform.position.z - hit.transform.position.z),2));
mousePos = Vector3(Input.mousePosition.x, Input.mousePosition.y, desiredZ);

hit.transform.position = Camera.main.ScreenToWorldPoint(mousePos); It works, but does anyone have a more ellegant solution?

One more thing, everytime i click, it already moves a little bit the object, i just want it to moves after the click. Any ideas?

if (Physics.Raycast(ray, hit)) {
            newPosition = Vector3(Input.mousePosition.x, Input.mousePosition.y, hit.transform.position.z);
            hit.transform.position = Camera.main.ScreenToWorldPoint(newPosition);
}

The little "jump" that you keep experiencing is due to the grabDistance. what you really want to do is immediately do another raycast to simulate what the next frame would see with the Raycast layer of the grabbed object turned off. Then you can use the difference from the grabbed object's transform and that immediate second raycast as your offset for dragging.

The following is "smooth as silk" and also allows you to grab hierarchical objects -- well, single-layered ones at least :)

 var grabbed : Transform;
 var grabDistance : float = 10.0f;
 var grabLayerMask : int;
 var grabOffset : Vector3; //delta between transform transform position and hit point
 var useToggleDrag : boolean; // Didn't know which style you prefer. 
 
 function Update () {
     if (useToggleDrag){
         UpdateToggleDrag();
     } else {
         UpdateHoldDrag();
     }
 }
 
 // Toggles drag with mouse click
 function UpdateToggleDrag () {
     if (Input.GetMouseButtonDown(0)){ 
         Grab();
     } else {
         if (grabbed) {
             Drag();
         }
     }
 }

 // Drags when user holds down button
 function UpdateHoldDrag () {
     if (Input.GetMouseButton(0)) {
         if (grabbed){
             Drag();
         } else { 
             Grab();
         }
     } else {
         if(grabbed){
             //restore the original layermask
             grabbed.gameObject.layer = grabLayerMask;
         }
         grabbed = null;
     }
 }
 
 function Grab() {
     if (grabbed){ 
        grabbed = null;
     } else {
         var hit : RaycastHit;
         var ray : Ray = Camera.main.ScreenPointToRay(Input.mousePosition);
         if (Physics.Raycast(ray, hit)){          
             grabbed = hit.transform;
             if(grabbed.parent){
                 grabbed = grabbed.parent.transform;
             }
             //set the object to ignore raycasts
             grabLayerMask = grabbed.gameObject.layer;
             grabbed.gameObject.layer = 2;
             //now immediately do another raycast to calculate the offset
             if (Physics.Raycast(ray, hit)){
                 grabOffset = grabbed.position - hit.point;
             } else {
                 //important - clear the gab if there is nothing
                 //behind the object to drag against
                 grabbed = null;
             }
         }
     }
 }

 function Drag() {    
     var hit : RaycastHit;
     var ray : Ray = Camera.main.ScreenPointToRay(Input.mousePosition);
     if (Physics.Raycast(ray, hit)){      
         grabbed.position = hit.point + grabOffset;
     }
 
 },

hi gilson,i have same problem .do you solve it?could you plz show your complete code?