VS3D / VScad3 User's Guide




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VScad3 Model Manipulation

2.5.6 View mode.

This mode is used for panning, zooming, or rotating a view. When a view is zoomed or rotated, the center point of the scaling or rotation is located at the center of the Workspace Region. The Workspace Region can be set via the main "Workspace / Region..." menu. Manipulating a view merely changed the viewpoint from which the model is viewed. It does not change the entities themselves in any way. Light sources do not rotate with a view. They stay fixed relative to the screen. When a view is manipulated, any other views on the page will go dark (will not be drawn), so that better performance may be obtained for view manipulation. When the view manipulation is finished (the mouse button is released), all other views will become visible again.

"View" : This setting determines which view to manipulate. If there is only one view on the page, then this setting has no meaning. Clicking a mouse button on a view (while in "View" mode) will select that view for manipulation, and the "View" setting will be adjusted to the number of the view that was clicked on ("1", "2", "3", or "4").

"Pan | Zoom | Rotate" : This specifies the type of transform to be applied to the view.
In "Pan" mode, click and drag a mouse button to pan the view in the desired direction.
In "Zoom" mode, click and drag the right mouse button upwards (towards the top of the screen) to zoom the view larger. Drag downward to zoom the view smaller.
In "Rotate" mode, click and drag the left mouse button left-right & up-down to rotate the view in 3D about the X and Y screen axes. Click and drag the right mouse button to pivot the view about the screen Z axis.

"Vector..." : This will bring up the view transformation dialog for typing in the view parameters.
In "Pan" mode, enter the X,Y "Pan Vector" (distance).
In "Zoom" mode, enter the "Zoom Factor". The Zoom Factor must be greater than 0.
In "Rotate" mode, enter the X,Y,Z "Rotate Axis" vector, and the "Rotate Angle" (in degrees counter-clockwise).

"Eye..." : This will bring up the "View Eye Point" dialog. The view type can be set to an "Orthogonal" (parallel) projection, or a converging "Perspective" projection. The Near and Far Z clipping plane positions are measured relative to the screen and they control the near and far display clipping of entities. These settings will override the settings entered in the Workspace Region dialog. After a view has been set to the desired orientation, use the View mode "Eye" dialog to move the far clipping plane out to a far distance so that no distant geometry is clipped (typically, best results are obtained by setting the Far Z clipping plane distance to a large negative number).

The "Eye Point" setting determines how close the eye is to the model for Perspective projections. The Eye Point setting has no effect on Orthogonal projections. The Eye Point should be closer to the screen than the Near Z clipping plane position. If an Eye point distance is entered which puts the Eye Point inside the clipping planes, then the Eye Point will automatically be bumped just outside the Near Z clipping plane. So, to specify the most drastic (least parallel) view possible with the current view, enter an Eye Point of 0 and let the system adjust it accordingly.

"Reset" : This will reset the view back to it's default un-panned, un-zoomed, and un-rotated orientation. The main Workspace Region setting determines the default view area.

2.5.6 A