Detail Attributes of Linear Dimensions

To save space on the paper, a parallel dimensions may be produced in a truncated form. Figure 12:12 below shows the truncated form of the dimension shown in Figuree 12:8 in .

Figure 12:12. Truncated Parallel Dimension

The truncation is produced by the TRUNCATE command, which has two forms as shown in the examples below.

For non-truncated parallel dimensions, the spacing between each dimension line is given an initial default value calculated to be sufficient to allow room for the dimension value (or a single line of dimension line text). The spacing is controlled by the Dimension Line Separator Attribute (DMSP).

In a macro, the separation can also be set in terms of Sheet or screen coordinates. Note that the minimum separation is governed by the DMSP attribute - the calculated spacing cannot be less than this minimum. shows the effect of varying the spacing.

Figure 12:13. Parallel Dimension Line Spacing

The initial value of DMSP is cascaded down from LAYE level

Dimension line text (DMTX) is set by a command of the form:

DMTX 'text’'

Figure 12:14. Dimension Line Text

#DIM in the example above takes the value of the dimension. #DIM is a simple case of intelligent text - see Intelligent Text. Note that in the case of non-truncated parallel dimensions, the dimension line spacing will automatically be adjusted to accommodate two or more lines of text if these are input. Dimension line text may be set at Dimension Point or Dimension level, although in the latter case the text input will attached to all the dimension lines involved. Associated commands are:

Dimension text is automatically centre-justified, but its position relative to the dimension line may be varied by changing the setting of the dimension text offset (DTOF) attribute. For example:

Note also:

The dimension text origin is at the centre of and approximately half a character height ‘below’ the text.

Note that if there is insufficient space between the ends of two projection lines to enable the dimension line text to be fitted in parallel to the dimension line it will be automatically rotated by 90 degrees. Reducing the text character size (see below) may result in their being enough room to display the text parallel to the dimension line.

Dimension text angle can be controlled using the DTANGLE attribute. This is available both at dimension and dimension point level. Possible settings are:

DTANGLE STANDARD

DTANG HORIZ

DTANG VERT

DTANG EXTERNAL

DTANG PARALLEL

PTANG DEFAULT

The STANDARD setting gives dimension line text parallel to the dimension line except when there is insufficient room for it, when it is drawn parallel to the projection-line - that means, external dimension line text. STANDARD is the default setting for Dimension elements. The text is positioned by default just above the middle of the dimension line except that external text is centered on the centre of the dimension line. If the text is not external, then its position is constrained to lie between the projection lines.

The HORIZONTAL and VERTICAL settings cause the dimension line text to be drawn respectively horizontally or vertically in the VIEW. By default the text is centered on middle of the dimension line.

The EXTERNAL setting forces the dimension line text to be drawn parallel to the projection line even though there is room for it to be drawn parallel to the dimension line. By default the text is centered on middle of the dimension line. If the text would not be external in the STANDARD case, then its position is constrained to lie between the projection lines.

The PARALLEL setting forces the dimension line text to be drawn parallel to the dimension line even though there may be insufficient space for it to fit. By default the text is positioned just above the middle of the dimension line. If the text would not be external in the STANDARD case, then its position is constrained to lie between the projection lines.

The DEFAULT setting is only available at Dimension Points. This allows the DTANGLE value to be taken from the Dimension element (LDIM or ADIM). Otherwise the setting at the Dimension Point is used. This is the default setting for Dimension Points.

Figure 12:15. Dimension Line Text Angle

Projection line text (PLTX) is set and manipulated in a similar way. For example, the commands:

PLTX ’PUMP /1501A’

PLTX ’PUMP /1501B’

(each at the appropriate dimension point level) could be used to give the text shown in .

Figure 12:16. Projection Line Text

Note also:

Projection line text axes are oriented relative to the projection line. The orientation is controlled by setting the PTOF attribute.

See for an example of changing the projection line text offset.

Figure 12:17. Projection Line Text Offset

Other options are:

Projection line text is justified ‘towards’ the appropriate dimension point by default, but may be justified ‘away’ from the dimension point or may be centered on the projection line, using the commands:

PJUST AWAY

PJUST CENTRE

Figure 12:18. Projection Line Text Justification

The initial value of PJUS is cascaded down from LAYE level.

Projection text angle can be controlled using the PTANGLE attribute. This is available both at dimension and dimension point level. Possible settings are:

PTANGLE HORIZ

PTANG VERT

PTANG STAN

PTANG DEF

The HORIZONTAL and VERTICAL settings cause the projection line text to be drawn respectively horizontally or vertically in the VIEW. In these cases, the projection line is not extended automatically to underline the text but only overshoots the dimension line by the distance specified by the OSHT attribute.

The STANDARD setting gives the projection line text parallel to the projection line. This is the default value for Dimension elements.

The DEFAULT setting is only available at Dimension Points. This allows the PTANG setting to be taken from the Dimension element (LDIM or ADIM), otherwise the setting at the Dimension Point is used. This is the default setting for Dimension Points.

Figure 12:19. Projection Line Text Angle

The standard character height for dimension line and projection line text is 4mm (cascaded from LAYE level), but this may be varied by commands such as:

Initial settings of these attributes are cascaded down from LAYE level.

Other text attributes (present at Dimension and Dimension Point level) are:

Initial settings of these attributes are cascaded down from LAYE level. See Miscellaneous Text Facilities for further information of letter height and text fonts.

Dimension line and projection line text can be edited through use of the EDTEXT command. In the following examples, the target string is ‘ACCESS DPACE’, = ‘ACCESS SPACE’ mistyped:

Note: When editing intelligent text the intelligent text code itself must be specified, not the resultant text. See Miscellaneous Text Facilities for full details of the EDTEXT command.

Dimension line terminators are arrowheads by default, but may be obliques, dots, or absent altogether - see .

Figure 12:20. Dimension Line Terminators

The terminators (DTER attribute) are set by the commands:

DTER ARROWS

DTER OBLIQUES

DTER DOTS

DTER OFF

Note: The first terminator of a truncated dimension (see ) can be set independently using the FTER attribute. The first terminator will be drawn 25% larger than the remainder.

FTER can have any of the same settings as DTER, or can be DEFAULT, in which case FTER assumes the same setting as DTER. FTER is applicable to LDIMs and ADIMs, or can be set at LAYE level, in which case its setting will be cascaded down to newly-created dimensions.

The size of the terminator is controlled by the TSIZ attribute:

The initial settings of DTER and TSIZ are cascaded down from LAYE level.

The line styles and colours used for dimension and projection lines may be set by

At an LDIM the initial settings of these four attributes are cascaded down from LAYE level. At dimension point level their initial values will be DEFAULT, that means, they use the values from the owning LDIM. See Colors and Styles for further information of colours and line styles.

Gaps in projection lines are most easily defined using the cursor, with either the start and end points or a mid point and a length being specified. Examples of the relevant commands are:

Up to ten gaps may be inserted in the projection line. Note that if the position of a Dimension is changed so as to substantially alter the path of the projection line then it will be redrawn solid until the gaps are redefined.

Gaps may be highlighted by giving the command:

SKETCH GAPS

at any element that contains gaps. A circle will be drawn with diameter equal to the gap length, centered on the gap centre. The command:

ERASE GAPS

will remove the circles. Either of the above commands may have an element name after the main command if the required element is not the current element.