Re: [osg-users] Trackball and view question
Question 1) : You are trying to retrieve the Euler angles (i.e. rotation about X,Y,Z in some order) from a matrix. You can google for Euler and Matrix; alternatively start here: http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToEuler/index.htm Question 2) : As mentioned in previous replies, the translation retrieved will incorporate the lookDistance of the camera; hence you need to store and control the lookDistance of the camera - this is a bit similar to the idea of zoom on the trackball. For what it's worth, I do this with a combination of distance = (eye-centre).length(), trackball-setDistance(distance), and also retrieve the matrix with trackball-getInverseMatrix().getLookAt(eye,look,up,distance). David ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trackball and view question
Hello,
I am still stuck on this problem... :( Here is some concrete code so that maybe
someone
can help me figure it out and for those who understand code better than english
:)
First we are given a camera position (in world coordinate
system) and an orientation. The orientation is the yaw / pitch / roll to
transform the
vector (0,0,1) to the desired camera view direction.
osg::Vec3 camTrans(0.1443978698344,
0.0204530392050 ,
0.0124436690688 );
osg::Vec3 camRot(5.4461109291 ,
-4.7768289550 ,
90.9259008041 );
To set the view in the viewer I do:
/*
setView() method
Set view in viewer given camera
translation and rotation.
*/
osg::Vec4 vsCtr(0.0, 0.0, 1.0, 1.0);
osg::Vec4 vsUp(0.0, 1.0, 0.0, 0.0);
osg::Vec4 vsEye(0.0, 0.0, 0.0, 1.0);
osg::Vec4 newCtr, newUp, newEye;
osg::Matrix rotX, rotY, rotZ, transXYZ;
rotX.makeRotate(Deg2Rad(camRot.x()), osg::Vec3(1,0,0));
rotY.makeRotate(Deg2Rad(camRot.y()), osg::Vec3(0,1,0));
rotZ.makeRotate(Deg2Rad(camRot.z()), osg::Vec3(0,0,1));
transXYZ.makeTranslate(camTrans);
newCtr = vsCtr * rotZ * rotY * rotX * transXYZ;
newEye = vsEye * rotZ * rotY * rotX * transXYZ;
newUp = vsUp * rotZ * rotY * rotX * transXYZ;
osg::Vec3 v3Eye(newEye.x(), newEye.y(), newEye.z());
osg::Vec3 v3Ctr(newCtr.x(), newCtr.y(), newCtr.z());
osg::Vec3 v3Up(newUp.x(), newUp.y(), newUp.z());
pMainCam-setViewMatrixAsLookAt(v3Eye, v3Ctr, v3Up);
This works well. Now I want to be able to have
a function that gives the translation / orientation
from the current view matrix:
/*
getView() method
Find position and orientation parameters from view matrix
*/
osg::Matrix viewMat = pMainCam-getViewMatrix();
osg::Matrix invViewMat;
invViewMat.invert(viewMat);
osg::Vec3 translate = invViewMat.getTrans();
With this code I can recuperate the initial translation
(0.1443978698344, 0.0204530392050, 0.0124436690688).
Question 1:
How can I recuperate the initial rotation ?
(5.4461109291, -4.7768289550, 90.9259008041);
Question 2:
I'd like to add a trackball manipulator to my viewer.
I want to then position the view manually similar to what I
do in my setView() method. When I read back the translation,
the value is very different from (0.1443978698344, 0.0204530392050,
0.0124436690688).
How can I adapt my getView() to handle the trackball and give me
the value that I want ?
Any help / suggestion would be highly appreciated as I am struggling
with this.
best regards,
bill
-Original Message-
From: [EMAIL PROTECTED] on behalf of J.P. Delport
Sent: Fri 9/28/2007 2:36 AM
To: OpenSceneGraph Users
Subject: Re: [osg-users] Trackball and view question
Hi,
I am attaching an old email below that I think addressed some of the
same issues you are having.
Also attached is a code snippet of a modified manipulator base class I use.
regards
jp
Code:
---8--
/** get by distance, rotation, center. */
virtual void getDRC(double distance, osg::Quat rotation, osg::Vec3d
center) {
distance = _distance;
rotation = _rotation;
center = _center;
}
/** set by distance, rotation, center. This keeps the focus point
correct. */
virtual void setByDRC(double distance, osg::Quat rotation, osg::Vec3d
center) {
_distance = distance;
_rotation = rotation;
_center = center;
_thrown = false;
flushMouseEventStack();
}
Old email:
---8--
Hi Morne,
I've done something like this, though not exactly the same. One gotcha I
found was that getting the matrix from the Trackball was not enough to
reset it later. Internally the trackball works with a distance, rotation
and center, (thats a scalar, quat and vec3) and all this info is not
encoded in the final matrix used for drawing. I added getDRC and
setByDRC to the cameras I have.
You can prob find the code for these in the list archives. If you don't,
let me know.
regards
jp
ps. are you in South Africa by any chance?
Morné Pistorius wrote:
Hi,
I have a scene with various models loaded. I want to be able to double
click on a model and have the camera move and position itself in front
of the model, and afterwards return to the default trackball
manipulator.
I looked at the osgcamera and osganimation examples and I'm trying to
come up with a way of doing this. These are my thoughts:
1. Somehow get the current camera position and attitude from the
trackball manipulator.
2. Compute an animation path from this point to a point in front of the
model.
3. Replace the trackball manipulator with an AnimationPathManipulator
and set the animation
4. Once it is done, replace it with with the original trackball
manipulator and set its home position to the current camera position.
Does this sound like the right way to go forward? I would appreciate
any feedback on this, pointers or gothcas from people with more
experience than I have. Also
Re: [osg-users] Trackball and view question
Hi Bill, The camera manipulators role is to modifying the view matrix so I'm a bit perplexed that you are suprised by this. Also please considering move from SimpleViewer up to osgViewer::Viewer working as an embedded viewer in 2.x rather than using SimpleViewer as it only existed for a short while and has been totally superseded. Robert. On 9/18/07, Poirier, Guillaume [EMAIL PROTECTED] wrote: Hello everyone, I am using a SimpleViewer. I set up a post draw callback on its main camera. In it I read the camera eye, center, and up vectors. Initially, this give me (0, 0, 0), (0, 0, -1), and (0, 1, 0) respectively. This is what I expect and it gives me a particular view of my scene. Now I add a trackball manipulator to the main camera and set up the view similar to what I had previously. When I read back the data it is quite different. I would have expected the same camera position / orientation than before since what I see is similar. Unless the trackball affects the model position / orientation and not just the view ? How can I use a trackball and read back in the post draw callback the values I want ? sincerely, Bill ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trackball and view question
Hi,
I am attaching an old email below that I think addressed some of the
same issues you are having.
Also attached is a code snippet of a modified manipulator base class I use.
regards
jp
Code:
---8--
/** get by distance, rotation, center. */
virtual void getDRC(double distance, osg::Quat rotation, osg::Vec3d
center) {
distance = _distance;
rotation = _rotation;
center = _center;
}
/** set by distance, rotation, center. This keeps the focus point
correct. */
virtual void setByDRC(double distance, osg::Quat rotation, osg::Vec3d
center) {
_distance = distance;
_rotation = rotation;
_center = center;
_thrown = false;
flushMouseEventStack();
}
Old email:
---8--
Hi Morne,
I've done something like this, though not exactly the same. One gotcha I
found was that getting the matrix from the Trackball was not enough to
reset it later. Internally the trackball works with a distance, rotation
and center, (thats a scalar, quat and vec3) and all this info is not
encoded in the final matrix used for drawing. I added getDRC and
setByDRC to the cameras I have.
You can prob find the code for these in the list archives. If you don't,
let me know.
regards
jp
ps. are you in South Africa by any chance?
Morné Pistorius wrote:
Hi,
I have a scene with various models loaded. I want to be able to double
click on a model and have the camera move and position itself in front
of the model, and afterwards return to the default trackball
manipulator.
I looked at the osgcamera and osganimation examples and I'm trying to
come up with a way of doing this. These are my thoughts:
1. Somehow get the current camera position and attitude from the
trackball manipulator.
2. Compute an animation path from this point to a point in front of the
model.
3. Replace the trackball manipulator with an AnimationPathManipulator
and set the animation
4. Once it is done, replace it with with the original trackball
manipulator and set its home position to the current camera position.
Does this sound like the right way to go forward? I would appreciate
any feedback on this, pointers or gothcas from people with more
experience than I have. Also, if there are any examples that
better fit
what I am trying to do, I would be much obliged.
Thank you kindly,
Morne
---8--
Poirier, Guillaume wrote:
Well this is what I was trying, using
viewer.getCamera()-getViewMatrixAsLookAt(osg::Vec3 eye, osg::Vec3
center, osg::Vec3 up, float lookDistance=1.0f). In step 2 (with trackball
manipulator) I read back the
eye, center, and up values in the camera post draw callback. When the pose is
almost identical as in the
first step, I read the values and they look quite different than what I was
setting in the first step. I am still
unclear whether this is normal or not. So my question is, if it's normal,
is there a transformation
I can do to recuperate the step 1 values ? Or do I need to implement a custom
view manipulator to achieve
what I am looking for ?
regards,
bill
-Original Message-
From: [EMAIL PROTECTED] on behalf of Alberto Luaces
Sent: Thu 9/27/2007 4:38 AM
To: OpenSceneGraph Users
Subject: Re: [osg-users] Trackball and view question
Hi Robert et al.
Let me explain what I want to do accomplish an example:
I load a model with no camera manipulator. I know the camera parameters
(eye, ctr, up)
that yield a desired pose. I set the viewer camera with those parameters and
obtain the
desired pose.
Now I want to assume that I don't know those parameters. A user loads a
model with a trackball
manipulator. He / she can manipulate the model until the desired pose is
obtained and
recuperate the camera parameters (eye, ctr, up), which should be what I used
in the previous
step...
Is that more clear ? How would I achieve this ?
regards,
Bill
What about osg::Camera::getViewMatrixAsLookAt (osg::Vec3 eye, osg::Vec3
center, osg::Vec3 up, float lookDistance=1.0f) ?
Alberto
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Re: [osg-users] Trackball and view question
Hi Robert et al. Let me explain what I want to do accomplish an example: I load a model with no camera manipulator. I know the camera parameters (eye, ctr, up) that yield a desired pose. I set the viewer camera with those parameters and obtain the desired pose. Now I want to assume that I don't know those parameters. A user loads a model with a trackball manipulator. He / she can manipulate the model until the desired pose is obtained and recuperate the camera parameters (eye, ctr, up), which should be what I used in the previous step... Is that more clear ? How would I achieve this ? regards, Bill -Original Message- From: [EMAIL PROTECTED] on behalf of Robert Osfield Sent: Tue 9/18/2007 11:28 AM To: OpenSceneGraph Users Subject: Re: [osg-users] Trackball and view question Hi Bill, The camera manipulators role is to modifying the view matrix so I'm a bit perplexed that you are suprised by this. Also please considering move from SimpleViewer up to osgViewer::Viewer working as an embedded viewer in 2.x rather than using SimpleViewer as it only existed for a short while and has been totally superseded. Robert. On 9/18/07, Poirier, Guillaume [EMAIL PROTECTED] wrote: Hello everyone, I am using a SimpleViewer. I set up a post draw callback on its main camera. In it I read the camera eye, center, and up vectors. Initially, this give me (0, 0, 0), (0, 0, -1), and (0, 1, 0) respectively. This is what I expect and it gives me a particular view of my scene. Now I add a trackball manipulator to the main camera and set up the view similar to what I had previously. When I read back the data it is quite different. I would have expected the same camera position / orientation than before since what I see is similar. Unless the trackball affects the model position / orientation and not just the view ? How can I use a trackball and read back in the post draw callback the values I want ? sincerely, Bill ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org winmail.dat___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Trackball and view question
Hello everyone, I am using a SimpleViewer. I set up a post draw callback on its main camera. In it I read the camera eye, center, and up vectors. Initially, this give me (0, 0, 0), (0, 0, -1), and (0, 1, 0) respectively. This is what I expect and it gives me a particular view of my scene. Now I add a trackball manipulator to the main camera and set up the view similar to what I had previously. When I read back the data it is quite different. I would have expected the same camera position / orientation than before since what I see is similar. Unless the trackball affects the model position / orientation and not just the view ? How can I use a trackball and read back in the post draw callback the values I want ? sincerely, Bill ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Trackball and view question
Trackball and view questionHi, The trackballManipulator recomputes the home position (should be called home positions in fact since there are three of them) when the scene is set on the osgViewer if you don't call TrackballManipulator::setAutoComputeHomePosition(false). The View Matrix you'll get the first time is highly dependent of the TrackballManipulator::_homeCenter value (among others). Since it's a lookAt Matrix that is computed, you can have the impression your point of view is the same when looking your window even if you get different values in your code (if the direction of sight is the same, unnormalized, for example). Hope it helps, -- Christophe Médard Société OKTAL (http://www.oktal.fr) 2 impasse Boudeville 31100 Toulouse (France) Tél. : (+33) 5 62 11 50 10 Fax : (+33) 5 62 11 50 29 - Original Message - From: Poirier, Guillaume To: osg-users@lists.openscenegraph.org Sent: Tuesday, September 18, 2007 4:19 PM Subject: [osg-users] Trackball and view question Hello everyone, I am using a SimpleViewer. I set up a post draw callback on its main camera. In it I read the camera eye, center, and up vectors. Initially, this give me (0, 0, 0), (0, 0, -1), and (0, 1, 0) respectively. This is what I expect and it gives me a particular view of my scene. Now I add a trackball manipulator to the main camera and set up the view similar to what I had previously. When I read back the data it is quite different. I would have expected the same camera position / orientation than before since what I see is similar. Unless the trackball affects the model position / orientation and not just the view ? How can I use a trackball and read back in the post draw callback the values I want ? sincerely, Bill ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
