Getting The Mouse Coordinates

[mayanoob]

i want to continuesly monitor the mouse coordinates in the active viewport(x, y position)
how can i achieve this

Paul

[daniel-faust]

1.
You can do this with a MPxSelectionContext or a MPxContext.

There is a limitation on this, you won't be notified when the mouse hovers over the viewport, only on press, release, and drag.

Another limitation is that you need to enter that context, which means that you need to exit whichever context you were in, like move, select, rotate... This can be worked around if your context also implements the move tool and the selection tool, which are usually the normal contexts in which Maya is in. This is a bit difficult to implement, but very rewarding.

2.
Another way to do it is by positioning your code in a layer between of the OS and Maya, in the case of Windows you would install a Mouse Hook, in order to intercept mouse messages sent to from the OS to Maya. This is very flexible, but you need to check without the Maya API if you are above a viewport (classname ModelView) so this is really a hack and not the preferred way to work with Maya. But it is possible to get to the point to cast a ray into the scene from where the cursor hovers, I used it to implement smooth scrolling with the middle mouse button in layouts which allow scrolling, and also to check if I was hovering above certain objects in the scene, but this last function I moved into a context because this method had problems working together with the "artUserPaintCtx" (many redraws, very slow). So check before releasing that you are not messing up things like that because if s.o. uses such a context and it does not behave correctly with your hack, then you've got a big problem and need to start all over.

What do you want to do with that monitoring?

Daniel

[mayanoob]

continuously reading in the xyz coordinates under the cursors position( using gluUnproject)

Paul

[rob-bateman]

not doing some form of your own selection are you? You can use MGlobal::selectFromScreen() ....

[daniel-faust]

and instead of using gluUnproject M3dView::screentToView() would avoid you from getting into using glut

[mayanoob]

hehe i've just implemented the gluUnproject function, along with glReadPixels, but right now another ''problem" arises, i want the new XYZ location as the new pivot point for my camera
i'm pretty sure i've seen it somewhere, but some of you guys can point me in the right direction, coz i don't want to right my matrix math again

Paul

[daniel-faust]

you want to translate the entire camera or only the pivot?

In any case, get the M3dView::activeView()
then the dag path of the camera with M3dView::getCamera(dagPath) (I'm not sure what the exact function names are), then with the dagPath you get the transform and perform the translation.

[mayanoob]

well both if possible, just like the way when you press ''f'' on an object, but in a same way how maya behaves, right now i've found a class (mfncamera) that has the function setTumblePivot

MDagPath camera;
m_View.getCamera(camera);
MStatus stat;
point.x = x1[0];
point.y = y1[0];
point.z = z1[0];

MFnCamera cam;
cam.copyViewFrom(camera);
cam.setTumblePivot(point);

which will asaik change the pivot, but i don't know for sure coz i'm also right new to the api, and come from an opengl/java background, so i still have the bad habit to progam everything myself;)

Paul

[daniel-faust]

if you want to move/modify the camera which is filming that viewport, then create the function set as with the dagPath in the constructor:

MDagPath camera;
m_View.getCamera(camera);
MFnCamera cam(camera);

You probably don't want to change the pivot but the entire camera, if you say "well both if possible". When you translate the entire camera, the pivot is translated automatically with it.

There are several ways to change the position of an object, usually the best (because it is the most consistent) is to use the MFnTransform, but in your case MFnCamera also provides all you need.

point.x = x1[0];
point.y = y1[0];
point.z = z1[0];

So you probably want to use the MFnCamera::setEyePoint(point, MSpace::kWorld); to position the camera and MFnCamera::setCenterOfInterestPoint(centerOfInterest, MSpace::kWorld); to specify where to look at.

[joojaa]

But eye point also moves the centering! it is best to actually manipulate the translate rotate matrix directly because otherwise you might jumble up any animation attached to the camera, making the method less than useful.

Trying to make a rotate around object are we?

[daniel-faust]

I have not tried setting the eyepoint, but the docs say that the center of interest will stay fixed.

[kursat-turkay]

if you mean screen coordinates. getting-adding-removing the default panel left position with this command
I believe you can get...

but this small code gets current mouse position. (I used it to make popup my windows under my mouse pointer)

maybe will useful.

CODE
#include
#include
#include
#include

using namespace std;

DeclareSimpleCommand(getcurPos, "ManualDesk", "8.0");

MStatus getcurPos::doIt( const MArgList& )
{

        MStatus stat;WINSTA_READATTRIBUTES;

        LPPOINT lpoint=new tagPOINT;

        ::GetCursorPos(lpoint);

        clearResult();

        appendToResult(lpoint->x);
        appendToResult(lpoint->y);

    return MS::kSuccess;
}

[daniel-faust]

Yes, you'd use GetCursorPos if you work with a mouse hook, a context already provides you with that information.

Joojaa, my mistake, your absolutely right, the only thing I'd also change were the length of the center of interest so that rotations always result in rotations around the centered object and not around some displaced center.

MDagPath camera;
m_View.getCamera(camera);
MFnCamera cam(camera);
MFnTransform transform(camera.transform());

those are the only classes needed then and how to initialize them.

[mayanoob]

thanks guys, it works, the reason why it wouldn't work in the first place was that i forgot to call M3Dview::activeView()

@ jojaa yeah i want to let the camera hover around a user defined point of inters

cheers,

Paul