Rayfront User Manual

Parallel View

A parallel view is normally used to display floor plans or evelations. A parallel view which is tilted with regards to the main orientation of the viewed objects is also called axonometry, and can serve to clarify spatial context. On the other hand, such a view may easily look a little akward or "unnatural", as all objects are displayed at the same scale, regardless of their distance.

Parallel View Properties

There is no single viewpoint in a parallel view. The viewpoint given to define the view just specifies the center of the image plane. All views are sent into the same direction, each from it's point on the image plane. A parallel view just cuts a volume of contant rectangular cross section through the model space.

There are also no opening angles in a parallel view. Instead, the horizontal and vertical size of the view are given directly in model units. The diagonal size is the actual digonal of the image in model units. There is no upper limit to any of those values. Since there are no opening angles, there can be no focal length either.

The diagram to the left illustrates the projection of the points on the image plane into the model space. This is obviously the simplest projection possible.

The diagram below illustrates the three dimensional properties of a parallel view. The virtual extrusion volume of the image plane (the rectangle to the left) is projected through the model space. Objects or parts thereof that are within this volume will be seen in the image, objects of parts thereof that are outside (shown with darker shading in the diagram) will be cut off.

Navigation: