Hi, There is a mode in our application where the user does not control the camera. The camera is initially set to look at the z=0 plane (perpendicular to the plane) at a fixed height. We then get notifications from the application to move the camera in x and y only.
I was looking at our code we had for that, and I found out that we may have been doing a mistake. On the other hand, the view looks correct so I wanted to ask for more insight on this. When the application comes in with a delta [x, y], we only move the frustum of the orthographic projection, without moving the camera. I would imagine the right thing to do would be to move the camera in [x, y] without changing the frustum. But for some reason just moving the frustum works fine. I am not sure if this is valid or not. [I do know that if we were in perspective we would have to move the camera, since the frustum is defined by the angle and ratio of the view.] Just as an example, we start by setting the camera: Code: camera->setProjectionMatrixAsOrtho(-100.0, 100.0, -100.0, 100.0, 0.0, 320); // frustum of [200X200] camera->setViewMatrixAsLookAt( osg::Vec3(0.0, 0.0, 320.0), osg::Vec3(0.0, 0.0, 0.0), osg::Vec3(0.0, 1.0, 0.0)); // [eye, center, up] then at a later time, the application may say: "move the camera in x=50, y=25" Instead of moving the camera location we just call: Code: camera->setProjectionMatrixAsOrtho(-50.0, 150.0, -75.0, 125.0, 0.0, 320); Without moving the camera. Cheers, Ron ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=48990#48990 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
