T-FLEX Parametric CAD. Fundamentals. 2D Design

Fundamentals. Two-Dimensional Design
300
Successful definition of a hatch contour requires the graphic
lines to form “tight” contour (with no gaps).
The result of the automatic tracing is affected by the parameters set for
this mode. The automatic search parameters are defined in a dialog
called by the option . In this dialog window, first of all specify the
types of the graphic lines to be considered in the automatic search for
the hatch contour.
The threshold value of the gaps between graphic lines is determined by
the parameter “Gap”. If the graphic lines pass at the distance, which is
less than or equal to that defined by the given parameter, then the
system will assume that they have an intersection point and may
therefore include them in the hatch contour.
The “Search:” parameter allows defining more specific requirements to the result of tracing a hatch contour.
If this parameter has the “External contour” value, then the system will search for the largest closed
contour. The internal contours are ignored in this case. When using the “Internal Contours” value, the
system finds the minimal contour which still contains the position of the pointer while searching. The
internal contours processing depends in this case on the state of the additional flag “Search for Islands
(Holes)”. If this flag is set, then be found internal contours are included in the resulting hatch contour (so that
the identified islands are not filled with a hatch). When the flag is cleared, the internal contours are ignored.
Scanning for hatch contours may take a while on very crowded drawings. Search can be restricted per the
“Only on Visible Part of Page” flag. In this case, only the entities will be processed whose outline boxes
overlap with a portion of the drawing display on the screen. An outline box is the least horizontally oriented
rectangle that fully covers the entity. Examples of outline boxes and contour processing situations are shown
on the following diagrams.
“Scan Fragment Lines” flag will add lines of 2D fragments for scanning the hatch contour. This flag is set
off by default meaning that lines of the fragments will not be considered when searching the closed contours.
Several contours can be selected subsequently. Should there be common graphic lines between different
contours, the contours get automatically joined along these lines.
Manual Hatch Contour Input Mode
When manually defining a hatch contour, object snapping is active. Moving the cursor over a drawing
element modifies the cursor appearance accordingly and pre-highlights the element. The object snapping can
be turned off by pressing on the icon on the “View” toolbar. In complicated situations, when snapping to
the right element is difficult, the elements can be selected by typing commands on the keyboard as described
below.