Using Vis(ible) Screen Picking to Select Items
Using Vis(ible) Screen-Picking to Select Items
As well as selecting items from a menu you may pick them from the screen using the mouse. A combination of selection from the menu and screen-picking may be used, they are simply different ways of performing the same task.
Screen quick-pick is always "live" in the graphics window once you have selected an object category that is capable of being picked, it is not necessary to select explicitly.
| Through quick-pick there is: | |
| "Scalar" picking of single items | Just click on the approximate centre of the item to select it. |
| "Rectangular Area" picking of a range of items | Click and drag out a rectangular area. Everything within the area is selected. |
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Within the panel there are the following further screen-picking options: |
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Will select automatically all "visible" items that are eligible.
Note that "visible" in this context means what is displayed
on the screen, but not necessarily what you can see.
Items hidden behind other items are still "visible", as are items off the border of the current window. A more precise definition of "All Visible" would be "things which would be visible in a wireframe plot autoscaled to fit in the current window". |
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| Screen Selection options: | |
| Is an alternative way of defining a rectangular area by picking two points at opposite corners. Eligible items within the rectangle are selected. | |
| Selects within a circular area. Click on the centre of the circle, drag out to define its radius and release to select eligible items within the circle. | |
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Selects within an arbitrarily shaped polygon. Select three or more points
(up to a limit of 100) to define the polygon, and close it when complete.
All eligible items within the polygon will be selected.
While the polygon may be any shape, and include concave sections, it should not be excessively complex; and it is also recommended that it should not have crossed edges since while these will work the algorithm used to distinguish "inside" from "outside" may become confused by them. |
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