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GUI.Matrix and setting center of rotation

Discussion in 'Immediate Mode GUI (IMGUI)' started by Predster, Mar 12, 2008.

  1. Predster

    Predster

    Joined:
    Sep 11, 2007
    Posts:
    145
    Greetings,

    I'd like to draw a little rotation radar thing using UnityGUI, like the middle dial (with the blue) here: http://www.itreviews.co.uk/graphics/normal/games/g125.jpg.

    Currently, I'm using GUI.Matrix to rotate the texture, but I can't seem to figure out how to define the center of rotation!

    I though of perhaps using GUIUtility.RotateAroundPivot, but after reading this thread:
    http://forum.unity3d.com/viewtopic.php?t=8834&highlight=rotatearoundpivot

    I gather it's not shipped yet.

    This is the code I am using (I want to ONLY get the rotation of the main camera on the Z-axis, and have the 2D texture rotate accordingly):

    Code (csharp):
    1. var rotationradar : Texture2D; //the radar image
    2. var target : Transform;   //assign main camera to this variable
    3.  
    4.  
    5.  
    6. function OnGUI () {  
    7.   var tOffset = Vector3.zero;   //transform
    8.   var tScale = Vector3.one;     //Scale
    9.   var newRotation = target.rotation.eulerAngles.z;   //rotation variable
    10.   GUI.matrix =  Matrix4x4.TRS(tOffset, Quaternion.Euler(0, 0, newRotation), tScale);
    11.        
    12.   GUI.Label(Rect(10, 10, 320, 240), rotationradar);  //draw Gui element
    13. }
    14.  
    15. function Update () {
    16. transform.rotation.eulerAngles.z = target.rotation.eulerAngles.z;   //get the rotation on the z-axis
    17. }
    Can anyone help out? Thanks.
     
  2. Brian-Kehrer

    Brian-Kehrer

    Joined:
    Nov 7, 2006
    Posts:
    411
    this is a little thing i made


    Code (csharp):
    1.  
    2. var difference = (((angleBetween + Mathf.PI) * Mathf.Rad2Deg) - CameraTransform.eulerAngles.y);
    3. //this is an angle of rotation
    4.  
    5. var tempv2 = Vector2(Screen.width/2, Screen.height - 40);
    6. //this is pivot point
    7.  
    8.     GUIUtility.RotateAroundPivot(difference,tempv2);
    9.     GUI.Label(Rect(tempv2.x-15, tempv2.y-15,30,30),CompassMark);
    10. //the -15 makes sure the pivot is centered since its 30,30
    11.  
     
  3. Aras

    Aras

    Unity Technologies

    Joined:
    Nov 7, 2005
    Posts:
    4,770
  4. Predster

    Predster

    Joined:
    Sep 11, 2007
    Posts:
    145
    Awesome! It appears to be shipped. But I'm not sure exactly how to use it (from the docs). :oops:

    Code (csharp):
    1. RotateAroundPivot (angle : float, pivotPoint : Vector2)
    Can I just set the pivot point as two screen coordinates e.g. ( Vector2(50,50))?
    If I want it to rotate around 360 degrees (with camera rotation), can I just set it to 360 degrees?
     
  5. Brian-Kehrer

    Brian-Kehrer

    Joined:
    Nov 7, 2006
    Posts:
    411
    see my previous example


    or here, clarified

    Code (csharp):
    1.  
    2. var theAngle : float = 45.0;
    3. //this is an angle of rotation
    4.  
    5. var thePoint : Vector2 = Vector2(100,100);
    6. //this is pivot point
    7.  
    8. GUIUtility.RotateAroundPivot(theAngle,thePoint);
    9. //i think everything below this gets rotated
    10.  
    11.    GUI.Label(Rect(thePoint.x-15, thePoint.y-15,30,30),"hello");
    12. //the -15 makes sure the pivot is centered since its 30,30
    13.  
    to match camera rotation, hmm - a quick way
    Code (csharp):
    1.  
    2. var theCamera : Camera;
    3. function Update(){
    4. var theAngle = theCamera.transform.eulerAngles.y;
    5. }
    6.  
     
  6. Predster

    Predster

    Joined:
    Sep 11, 2007
    Posts:
    145
    Thanks Brian! But this code gives me an "Unknown Identifier" error for "theAngle"

    to match camera rotation, hmm - a quick way
    Code (csharp):
    1.  
    2. var theCamera : Camera;
    3. function Update(){
    4. var theAngle = theCamera.transform.eulerAngles.y;
    5. }
    6.  
    [/quote]

    Does it need to be defined elsewhere, for instance

    Code (csharp):
    1. var theAngle : float = 45.0;
    2. //this is an angle of rotation
    As in the first example?


    Edit: Whoops I completely missed your first post, also thanks!
     
  7. Brian-Kehrer

    Brian-Kehrer

    Joined:
    Nov 7, 2006
    Posts:
    411
    yeah, that was just psuedo code. Make it a public variable or something


    Code (csharp):
    1.  
    2. var theAngle : float = 0.0;
    3.  
    4. function Update(){
    5. theAngle = .....
    6.  
    7. }
    8.  
     
  8. Predster

    Predster

    Joined:
    Sep 11, 2007
    Posts:
    145
    Ok, I see :oops:

    Basically, I've been trying to set that variable to a variety of constants between 45 and 360 degrees and it hasn't changed anything. Also, changing the Vector2 values hasn't changed anything either.

    The script I have doesn't seem to have any errors, but also doesn't change the center of rotation at all :x


    Code (csharp):
    1.  
    2. var rotationradar : Texture2D; //the radar image
    3. var target : Transform;   //assign main camera to this variable
    4.  
    5. function OnGUI () {  
    6.   var tOffset = Vector3.zero;   //transform
    7.   var tScale = Vector3.one;     //Scale
    8.   var newRotation = target.rotation.eulerAngles.z;   //rotation variable
    9.   var thePoint : Vector2 = Vector2(210,170);
    10.   var theAngle : float = 360;
    11.   GUI.matrix =  Matrix4x4.TRS(tOffset, Quaternion.Euler(0, 0, newRotation), tScale);
    12.   GUIUtility.RotateAroundPivot (theAngle, thePoint);  
    13.      
    14.   GUI.Label(Rect(50,50, 320, 240), rotationradar);  //draw Gui element
    15. }
    16.  
    17. function Update () {
    18. transform.rotation.eulerAngles.z = target.rotation.eulerAngles.z;   //get the rotation on the z-axis
    19. }
    20.  
    21.  
     
  9. Brian-Kehrer

    Brian-Kehrer

    Joined:
    Nov 7, 2006
    Posts:
    411
    try this
    EDIT: make sure your rotation is in the z axis, usually for fps it's in the y axis -- also, i just tested this, and it works.

    Code (csharp):
    1. var rotationradar : Texture2D; //the radar image
    2. var target : Transform;   //assign main camera to this variable
    3. var theAngle : float = 0.0;
    4. var thePoint : Vector2 = Vector2.zero;
    5.  
    6. function OnGUI () {  
    7.  
    8.  
    9.   GUIUtility.RotateAroundPivot (theAngle, thePoint);
    10.      
    11.   GUI.Label(Rect(50,50, 320, 240), rotationradar);  //draw Gui element
    12. }
    13.  
    14. function Update () {
    15.  
    16.   thePoint = Vector2(210,170);
    17.   theAngle = target.rotation.eulerAngles.z;
    18.  
    19. }
     
  10. Predster

    Predster

    Joined:
    Sep 11, 2007
    Posts:
    145
    Brian, thanks!! It works!! :D :D :D

    I do need it for the z-axis--I've added a script to the main camera for "barrel roll" type rotation, so I wanted a gauge to show the rotation.