Using camera rotation around its own axis

 Using camera rotation around its own axis Using camera rotation around its own axis

 Rotation of camera around its own axis allows the change the shape of the view area projection. This feature can be useful in CCTV design. By turning a camera you can exclude from the view area unnecessary objects or vice versa expand the view area in the needed direction, without replacing the lens to a short-focus one, so without sacrificing the pixel density. At this a little rotation doesn't worsen readability of camera image for an operator.

Problem

Study the effect of camera rotation around its axis on the form of the view area projection.

Order of work

 1. Create new camera by the same way as in the previous examples.   2. Place several 3D models within the camera's view area.   3. For better clearness choose View area projections bounds>2 Levels, Fill projections>Filling.   4. Open the 3D Video.   5. Open the Camera geometry box and try to change value in the Axial rotation angle, watching on the form  of the view area projection in the 3D Video.   The parameters in the Camera geometry box can not reflect the shape of view area rotated around its main optical axis. So the rotation around the axis within + -45 degrees does not affect the parameters. The parameters of the Camera geometry box continue to show values ​​as if the camera is not rotated.

When the rotation angle is more than 45 degrees, the parameters abruptly change their values to ones corresponded to the camera rotated on 90 degrees.

In this position the lateral faces of the view area will become the upper and lower faces, and upper and lower faces will become lateral ones.

When the rotation angle is more than 135 degrees, the parameters will reflect the initial position of the camera.

When reducing the camera tilt angle, the axial rotation transforms the projection of view area to a narrow beam. This is not the vertical projection, but the horizontal projection on the ground!

The beam can be endless.

The view area projection takes on even more unusual form when it is build taking into account the rotation around camera's axis and lens distortion at the same time. Below there is one of possible example.