 |
-
Click
Create Camera
.
The camera is created at the current viewpoint.
-
Click the Camera item in the specification
tree and rotate the model to see the camera symbol:
 |
This standard visualization
is not affected by any change of scale ("zoom"). In case you wish
to hide the camera representation, right-click the camera in the
specification tree then select Camera object > Hide/Show
Representation. Inversely, this command lets you show a
hidden representation. |
 |
You can create
several cameras at different locations to have different
viewpoints.
The camera which is taken into account to render a given image is
said to be active. Any other camera is inactive. |
-
Use the two spheres
and the two squares displayed in green on the 3D representation to
interactively manipulate and position the camera.
This visualization is affected by
changes of view scale (zoom) and is activated when selecting a
camera in the scene or in the specification tree. Otherwise, all
elements are set to the standard visualization. |
 |
 |
Conical camera
Pyramid height = focal length
and
Pyramid base = film dimensions |
Cylindrical
camera Plane = film dimensions
|
|
- the source point (1)
rotates the camera around its target point
- the target point (2)
rotates the camera around its source point
- the source green square translates and rotates the camera
around its target point
- the target green square translates and rotates the camera
around its source point.
Cameras are needed to render and view a scene. "An image is
worth a thousand words": the better the camera is positioned, the
more accurate the saying. |
-
Select the camera in the
specification tree then right-click and select Properties (or
press Alt+Enter). The Properties dialog box is
displayed:
-
In the
Lens tab, select the lens type: Perspective or
Parallel, i.e. to obtain a conical or a cylindrical projection. The
Preview area shows the result of your selection accordingly.
A conical camera
is equivalent to a standard camera, with a non-zero focal length.
Parallel lines in the camera line of view appear to intersect at
the same point.
Perspective cameras are used in most cases since they are close to
the human vision.
In the case of
a cylindrical camera, parallel lines never appear as
intersecting.
These cameras are mainly used to define architectural viewpoints.
|
-
Specify the Focal Length,
which determines the field of view, in millimeters.
The focal length is the distance between the camera origin and the
viewing plane.
In a cylindrical
projection, the focal length is replaced by a zoom factor which
determines the scale of view (i.e. Scale appears instead
of Focal Length in the dialog box). |
 |
 |
You can also specify the
camera view directly inside the preview window by zooming, rotating
or panning the view: |
 |
-
Click the Position tab to define the target and origin
position.
-
Select the Update
camera from View check box to adjust (i.e. center) automatically
the camera whenever the viewpoint is modified:
 |
 |
This avoids using the
Update from View contextual
command each time a viewpoint modification is done. |
-
Click OK when finished.
-
If you want
to position yourself behind the camera and observe the captured image,
select Window > 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 |
-
To 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.
|