How to manage the recorded camera

In this page, we explain how to manage the recorded camera. The recorded camera is available on componentSofaBaseVisual. You have three modes to manipulate the camera: rotation mode, translation mode and navigation mode.

The rotation mode

The camera can rotate, if you define the rotation center, the rotation axis and the rotation start point. The rotation path is visible if you check the option “if true, draw the rotation path”.

The translation mode

This mode enables to move the camera between intermediate camera positions. The camera path is then defined with a linear spline linking these intermediate positions.You can select the intermediate positions on the orthogonal views of the plugin image by double-clicking on the point. Each time you double-click on a point you have to update the ImageViewer component. Image:Example.jpg The camera can navigate along the path with a default view up, if you check the option “if true, translation will be performed”. To draw the translation path check the option “if true, translation path will be performed”. An example navigationInVolume.scn is available in the plugin image.

• How is camera orientation defined ? To define the camera orientation, you have to determine the look-at vector and the view-up vector. The camera looks at the next point of the linear spline. To define the up vector, we initialize it with a default value. Then in order to guarantee a stability during the navigation, the up vector is oriented almost in the same orientation. Indeed for each step n, the right vector is defined as the cross product between the previous up vector and the current focal vector.

The navigation mode

The navigation mode enables to move between selected intermediate camera view points. A view point corresponds to a camera position and a camera orientation. Therefore, the main difference between navigation mode and translation mode is that the camera orientation is defined in the navigation mode by interpolation between intermediate orientations. To save an intermediate camera view point select in the mouse manager (edit->Mouse manager) the operation “Save camera’s view point for navigation”. To navigate select the operation “Start navigation if camera’s view points have been saved”, which works if at least 2 view points have been saved. An example navigationRecordedCamera.scn is available in examplesComponentsvisualmodel.