Detail Attributes of Linear Dimensions

DRAW Reference Manual

Dimensions : Linear Dimensions : Detail Attributes of Linear Dimensions

To save space on the paper, parallel dimensions can be produced in a truncated form.

The truncation is produced by the TRUNCATE command, which has two forms:


TRUNCATE BY 5	- truncate affected dimension lines by 5%
TRUN TO 10	- truncate dimension lines to 10mm from nearest dimension point
TRUN OFF	- turn off truncation

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).


Example:
DMSP 30 - set separation to 30mm DMSP @ - set separation with cursor

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. The example illustrates the effect of varying the 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’


Example:
DMTX ’ACCESS SPACE’ DMTX ’ACCESS SPACE #/#DIM’

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


DMTX DEFAULT	- (at Dimension Point level): set dimension text to that of owning Dimension

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


DTOF 0 5	- move dimension text origin 5mm along axis parallel to projection line in text up vector direction (= perpendicular to dimension line in most cases)
DTOF @	- move dimension text origin to cursor position
DTOF N 1 @	- move x coordinate of dimension text origin to cursor position (y coordinate not changed)
DTOF N 2 5	- change y coordinate of dimension text origin by 5mm (x coordinate not changed)

Note also:


DTOF DEF	- use default Dimension offset value, not Dimension Point value
DTOF STAN	- equivalent to DTOF 0 0, the standard position
DTOF ENDP OF /LINE1 QUAL X500 Y500	- DTOF defined by a ‘constructed point’. Refer to Point and Line Construction for further information.

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 is automatically rotated by 90 degrees. Reducing the text character size can 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. The attribute 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, for example, 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 centred 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 centred 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 centred on middle of the dimension line. If the text is not 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 is not 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. The DTANGLE value can be taken from the Dimension element (LDIM or ADIM). Otherwise the setting at the Dimension Point is used, which is the default setting for Dimension Points.

Dimension line continuous mode (DLCNTMODE) flag is available on dimension points, dimensions and dimension styles. It is available on all dimension types, but it is most useful on linear dimensions. It is normally set on the end vertex of a dimension line segment, so that it only affects that particular segment.

The available values are:


ON	- continuous mode enabled
OFF	- continuous mode disabled
DEFAULT	- inherit value from owning dimension (dimension points only)
BYVSTYLE	- inherit value from dimension style

This flag applies in two situations.

•

When the placement of the dimension text is straddling the dimension line (which often happens when the text has two or more lines), the part of the line that would go through the text would normally be suppressed. If dimension line continuous mode is enabled, the line is drawn. If there are an odd number of text lines, the line may go through the text, the user can rectify this by moving the text, if required.

•

When the projection lines are close together, the dimension line and terminators are drawn outside the space to allow for the text to be positioned between the projection lines without being obscured by the terminators. When the text placement is parallel or external (DTAN is PARALLEL or EXTERNAL), with the text not overlapping the dimension line, the line between the terminators can be put back by setting the dimension line continuous flag to ON.

Dimension line extended (DAEXLL) flag is available on the LDIM. When the flag is set, and the dimension lines are EXTERNAL, moving the text parallel to the dimension line extends the dimension line to stay in line with the end of the text.

If this is the starting point:

Moving the text to the left beyond the end of the dimension line extends the dimension line to the left:

Moving the text to the right beyond the end of the dimension line extends the dimension line to the right:

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

PLTX ’PUMP /1501A’

PLTX ’PUMP /1501B’

(each at the appropriate dimension point level) can be used to produce text.

Note also:


PLTX STAN	- no projection line text (the standard option)
PLTX DEF	- use default Dimension setting, not Dimension Point setting

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


Example:
PTOF -5 -5

The example illustrates the projection line text offset.

Other options are:


PTOF @	- Set PTOF by cursor
PTOF STAN	- Equivalent to PTOF 0 0, the standard position
PTOF DEF	- Use default Dimension value, not Dimension Point value
PTOF CENTRE OF /CIRCLE1	- PTOF defined by a constructed point. Refer to Miscellaneous Text Facilities for further information.
PTOF N 1 @	- Move x coordinate of projection line text origin to cursor position (y coordinate not changed)
PTOF N 2 5	- Change y coordinate of projection line text origin by 5mm (x coordinate not changed)

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

PJUST AWAY
PJUST CENTRE

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

Projection text angle can be controlled using the PTANGLE attribute. The attribute 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, the default value for Dimension elements.

The DEFAULT setting is only available at Dimension Points. The PTANG setting can be taken from the Dimension element (LDIM or ADIM). Otherwise the setting at the Dimension Point is used, which is the default setting for Dimension Points.

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


DTCH 2	- set dimension line text character height (DTCH) to 2mm
PTCH 2	- set projection line text character height (PTCH) to 2mm

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

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


PLSP	- Projection text line-spacing
PFON	- Projection text Font
DFON	- Dimension text Font
DT COLOUR	- Dimension line text colour (cascaded down from LAYE’s TX COLOUR)
PT COLOUR	- Projection line text colour (cascaded down from LAYE’s TX COLOUR)
PTLH	- Projection text letter height (0.8* character height)
DTLH	- Dimension text letter height (0.8* character height)

Initial settings of these attributes are cascaded down from LAYE level. Refer to Miscellaneous Text Facilities for further information.

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


EDTEXT DMTX ’DPACE’ ’SPACE’	- Change dimension line text to ‘ACCESS SPACE’
EDTEXT PLTX ’DPACE’ ’SPACE’	- Change projection line text to 'ACCESS SPACE

Note:

When modifying intelligent text the intelligent text code itself must be specified, not the resultant text. The EDTEXT command is described. Refer to Miscellaneous Text Facilities for further information.

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

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

Note:

The first terminator of a truncated dimension can be set independently using the FTER attribute. Refer to Detail Attributes of Linear Dimensions for further information. The first terminator is 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 is cascaded down to newly-created dimensions.

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


TSIZ 4	- set size to 4mm (default 3mm

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

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


DLSTYLE integer/line_pattern, PLSTYLE integer/line_pattern	DLCOLOUR integer/colour_name PLCOLOUR integer/colour_name

At an LDIM the initial settings of these four attributes are cascaded down from LAYE level. At dimension point level their initial values are DEFAULT, for example, they use the values from the owning LDIM. Refer to Colours and Styles for further information.

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:


GAP @	- Specify gap by giving start and end points
GAP AT @	- Specify a default length gap (2mm) centred on given point
SETDEF GAP 15	- Set default gap length to be 15mm
GAP AT @ L 10	- Specify a 10mm gap centred on given point
GAP OVER @	- Specify gap start and end points with cursor, and delete all other gaps in line
GAP DELETE @	- Delete gap specified by cursor
GAP DELETE ALL	- Delete all gaps on the current projection line or dimension line

Up to ten gaps can 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 is redrawn solid until the gaps are redefined.