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Setting the Screen Scaling Mode

Determine the method used by ARC+ to scale your model

\sclmod

 

Choose the desired scaling mode: automatic, fixed, or off.

The new scaling mode takes effect immediately. The current scaling mode is indicated at all times on the status line.

A detailed discussion of the scaling modes is presented below.

Off Scaling Mode

In the off mode you have complete control of the view using the viewing commands and view and zoom control window settings. . In this mode you can view any part of the model closely. By moving the eye and target positions inside the model, you can display close-up interior views. Some parts of the model may lie off the screen.

Automatic Scaling Mode

When you switch to automatic mode, the view of your model is automatically scaled to fill the working window. If you subsequently change the view, the system rescales the projection to maintain a full-screen display.

You can use the zooming, panning, and scale commands or a zoom control window to temporarily override the automatic scaling. When you use any other viewing command, the automatic rescaling becomes active again.

image\ebx_1693072387.gif NOTE An exception to this mode is that the display is not automatically rescaled if the eye position lies inside or very close to the model in perspective mode. This helps to prevent perspective distortion of the display when you view the interior of the model in automatic mode.

Fixed Scaling Mode

Before you enter the fixed mode, set or zoom the view to display the desired part of the model. When you enter the fixed mode, the direction and scale of the view do not immediately change. However, the following viewing parameters are reset:

The target position is set to the center of the current zoom/pan rectangle.

The eye position is set according to the distance and direction from the current target.

The perspective cone is temporarily set (until you exit the fixed mode) according to the current screen scale.

Thereafter, you can conveniently rotate the eye position or change the mode of projection, and the display remains centered about the fixed target point in the middle of the working window.

The following commands operate somewhat differently in the fixed mode, as compared to the off or automatic modes.

Setting a predefined standard view (\planv, \elev, \axo) commands – do not change the target position and eye-target distance in fixed mode. Thus the display remains centered on the fixed target and the scale is maintained when you use these commands.

Setting the screen scale (\scale) command maintains the current viewing direction, but changes the eye and target positions to accommodate the scale that you specify.

View control window–the three-dimensional distance between eye and target can be changed by dragging the mouse. To override this and lock the eye-target distance, hold down the Alt key while dragging.