About the Camera Commands Toolbar

The Camera Commands toolbar is displayed by default under the Menu bar when accessing the Real Time Rendering 2 workbench:

1. Select a camera in the list (where you see "None" right now) which contains all the cameras you may have previously created. The camera commands are activated:

   Note that if the camera you selected is a cylindrical camera (i.e. the lens type is "parallel"), only the first two commands will be activated because the Manipulate Focal command only applies to conical cameras (i.e. with a "perspective" lens).

2. If you want to position yourself behind the camera and observe the captured image, click Camera Window : a new window displaying the camera viewpoint is opened. When you manipulate the handler in this window, the camera is simultaneously positioned in the main window.

   You can choose three arrangements for the opened windows, i.e. horizontal, vertical and cascading by selecting the following commands from the menu bar: Window > Tile Horizontally Window > Tile Vertically Window > Cascade.

   Example of vertical tiling

   Once the Camera Window command is activated, the icon turns from to . To deactivate the command and close the camera window, you can either click the cross in the top-right corner of the window or reselect Window > Camera Window > Camera x.

3. To adjust (i.e. center) the camera when the viewpoint is modified, click Update from View .
   Do not forget that each time the viewpoint is modified, you need to click Update from View to re-adjust the camera.

   Picture 1 - Camera with starting viewpoint	Picture 2 - Camera after viewpoint modification
   If you want the camera to be adjusted automatically each time the viewpoint is changed, double-click Update from View (which turns ). To go back to the standard update mode, just click the icon again. Another method to adjust automatically the camera is to access the camera properties then select the Update Camera from View option. If you want to switch from one camera to another and position yourself behind the selected camera, press the Shift key and click camera.xxx in the Camera Commands toolbar.

4. Click Manipulate Focal to modify the focal length (i.e. the distance between the camera origin and the viewing plane) directly in the 3D viewer.

   A green circle appears with an arrow indicating the current focal length in millimeters as shown below:

   You can then drag the green arrow clockwise to increase the focal length or anticlockwise to decrease it. When you drag the arrow, the value in millimeters is updated and the focal length changes accordingly. The position of the camera origin is also modified simultaneously (the camera moves backward or forward) so that the model always fits into the camera field of view. Therefore, the perspective is modified without having to zoom in or out afterwards.

   The focal length can also be defined via the camera properties in the Lens tab. If you access the Properties dialog box, you see that the value displayed in the viewer matches the one displayed in the Focal Length box. Activating the Manipulate Focal command also keeps the Update from View command activated (the icon turns ): this means that the camera is automatically updated each time the viewpoint is modified. There is no need to click Update from View after each modification of the viewpoint.

   To exit the Manipulate Focal command, click .