Perspective View

3D-design usually utilizes the isometric 3D depiction. This means that a line located very far back appears to be as long on the screen as the distance located further to the front.

In reality, however, distances appear to shrink the farther they are removed from an object. This effect can be simulated with the perspective view.

The perspective view is a form of free view using a fictional camera. You are prompted for the position of source point (camera) and target point (motif, centre of picture) and this determine the line of vision. The parameter Focal Distance is used to indicate - as in photography - the focus of the camera. Larger values are used to zoom the object as if using a telephoto lens. Smaller values create a wide-angle effect.

The parameter Distance is used to subsequently change the distance to the target point and move back and forth along the indicated line of vision.

If you select the command, the following message appears in the command line: Select the desired function Off/Distance/Focal Distance/ <Set>. You can now select a function or select the command directly using the corresponding button:

Setting	Description
Set	The perspective view is activated. This requires that you first enter the target and source point of the view and then the focal distance of the camera. The program switches now to the perspective view.
Off	The perspective view is deactivated. The program switches now back to the isometric view.
Focal Distance	Here you can change the focal distance of the camera.
Distance	Here you change the distance of the camera from the target point.

Lines of vision changes are only possible using coordinates and the pick function is deactivated. Changing to the model global view does not yield the desired result until the perspective view is deactivated again.

Note: Remember that the perspective view is only a display view and does not allow any changes. For that, switch back to the isometric display.

In the following, you will see some examples of the difference between the perspective and the isometric display as well as the effect of the focal distance on the isometric display:

Isometric Display

The point down on the left (0,0,0) is also the point of origin of the world coordinate system.

3D Global View Isometric Display

You see a view with the settings

Target point = (5000,0,5000)

Source point = (5000,-100,5000)

Front View Isometric Display

Perspective Display

The source and target points are first set identically to the points of the isometric view.

However, since the picture is much too large, the distance from camera to target is increased to 30000.

This corresponds with the source point (5000,-30000,5000).

Front View Perspective View

Focal distance = 100

The focal distance of the camera is increased but the picture shows only a section of the result.