Applet
There are two parts to the applet - one is the User Interface Panel
and the other is the Canvas where the images are displayed.
User Interface Panel
The Interface panel allows the user to input the values necessary to
control the camera and perspective transforms. The input values are
- Approximate Up Vector
- Look To Vector
- Look From Vector (Camera Position)
- Near Plane Distance
- Far Plane Distance
- Screen Height
The default values can be changed by two methods. One method is to
change the values directly in the textfield. The value is accepted
only when you hit the ENTER key. The textfield accepts only integer values,
both positive and negative.Another method is to increase or decrease
the values by 1 by clicking on the ">" and "<" buttons.
Canvas
There are four different canvases which display images of the object and
the viewing frustrum.The objects along with the frustrum can be rotated by dragging the
mouse over the particular canvas. This is possible only in the World,
View and Screen space. By rotating the images, you can view the object
from all sides of the viewing frustrum.The Far Plane of the frustrum
is colored blue, and the Near Plane is colored Yellow. This color
coding is consistent in the World Coordinate Space, View Coordinate
Space and the Screen Coordinate Space. The UP vector is indicated by the Green Arrow.
- World Coordinate Space
In the World Coordinate Space,
the X, Y and Z axes rotate along with the object and the frustrum and
this helps to understand the position of the object in the World Space
- View Coordinate Space
- Screen Coordinate Space
- Screen Projection
Click here to see the JAVA Applet for
Camera and Perspective Transforms