Appearance of Radial Dimensions - Specific Attributes

The Radius/Diameter flag (DFLAG) attribute controls whether the RADIUS or DIAMETER is evaluated by the AKEY attribute as well as whether the dimension line is drawn from the centre (Radius) or across the diameter (Diameter). The default setting is RADIUS.

Figure 12:23. Radial Dimensions - DFLAG Setting

The Dimension Text (DMTX) attribute has the initial setting #DIM, which gives the value of the dimension controlled by DLFAG. For example for AKEY RINS and DFLAG DIAM, the text ’#DIM’ will be evaluated as the inside diameter of the element identified. The resulting value will be output on the drawing in place of this codeword. #DIM is a simple case of intelligent text - see Intelligent Text.

The Dimension Line Angle (DDEG) attribute controls the angle at which the dimension line is shown, relative to the 2D coordinate system of the VIEW. The default value is 0 (horizontal in the VIEW). Note that this is only horizontal in the Sheet when the VIEW has RCOD UP. DDEG may be set explicitly or by using the cursor (that means, DDEG @).

The Text Radius Flag (DTFLAG) attribute controls whether the text radius DTRAD (see below) is measured from the CENTRE, MIDPOINT or CIRCUMFERENCE of the radial dimension. The default setting is CENTRE. For radius dimensions, MIDPOINT is the midpoint between centre and circumference; for diameter dimensions MIDPOINT is the same as CENTRE.

The Text Radius (DTRAD attribute) is a signed distance (in Sheet units) that defines the radial position of the dimension text origin from the centre or circumference (according to the DTFLAG setting) of the dimensioned object. In the latter case, DTRA= 0 (the default value) means that the text origin is positioned at the 2D projection of the circumference of the object dimensioned.

If the text origin lies outside the circumference then the text is justified towards the centre of the circle. If the text lies inside the circumference then the text is centre justified unless the DSTYL is LEADER. In this last case, the justification is towards the circumference.

Text radius can be negative. For DTFLAG CIRCUMFERENCE, a negative value means inside the circumference. For DTFLAG CENTRE, a negative value places the text on the opposite side of the centre to its usual position. This is equivalent to reversing DDEG with a positive DTRA value.

Figure 12:24. Radial Dimensions - DTRA Setting

The Dimension Text Angle (DTANGLE) attribute controls the Dimension text angle. Possible settings are:

DTANGLE STANDARD

DTANG HORIZ

DTANG VERT

The default setting of DTANG is STANDARD. In this case the text is orientated radially. See Figure 12:25 below for the effects produced by changing DTANG.

Figure 12:25. Radial Dimensions - DTANG Setting

The Dimension Text Offset (DTOF) attribute defines the displacement of the text position from the text radial position. DTOF is a 2-dimensional array attribute. DTOF(1) defines the displacement along the text path direction (that means, Radial, Horizontal or Vertical depending on the DTANG setting), and DTOF(2) in the text ‘upvector’ direction. The default/initial value of DTOF is (0,0).

Further control of the text position in the upvector direction is given by use of the vertical alignment attribute ALIG . The actual position of the text for DTOF(2)=0 will depend on the value of ALIG. This allows you to align text independently of the character height DTCH. See Label Text Manipulation for further details of ALIG.

The second component of text offset, DTOF(2), is always applied in the upvector direction. Its value may be positive, zero or negative. See See Figure 12:26 below for for the effects produced by changing DTOF(2).

As an alternative to entering two values, DTOF may be set using the cursor, that means,

DTOF @

Note: In , ALIG=BBODY unless otherwise indicated.

Figure 12:26. Radial Dimensions - DTOF(2) Setting

The definition of the direction of application of the first component, DTOF(1), is more complex:

For DTANG STANDARD and text outside the circumference (that means, DTFLAG CIRCUM, positive DTRAD), DTOF(1) is in the direction of the radial displacement outwards from the text radial position. (In this case, it is preferable to modify the text radius (DTRAD) rather than DTOF(1); DTOF(1) is best left set to zero).

For DTANG HORIZONTAL and text outside the circumference, DTOF(1) is horizontal from the text radial position. In this case, the sign of DTOF(1) is determined by the DDEG attribute; for DDEG between -90 and +90, positive DTOF(1) adjusts the text position to the right of the radial position of the dimension text; for DDEG between 90 and 270, positive DTOF(2) adjusts the text position to the left. See See Figure 12:27 below for

Similarly, for DTANG VERTICAL and text outside the circumference, DTOF(1) moves the text up for DDEG between 0 and 180; and down for DDEG greater than 180 and less than 360.

Figure 12:27. Radial Dimensions - DTOF(1) Setting - Text Outside Circumference

In all three DTANG cases, if the text lies inside the circumference, the direction in which DTOF(1) is applied is reversed. DTOF(1) is always applied in the direction away from the Circumference.

Thus for DTANG Horizontal and DDEG=45, when the text is outside the circumference then DTOF(1) adjusts text to the right. However when text is inside the circumference, then DTOF(1) adjusts text to the left.

For DTANG Standard, then DTOF(1) would move text radially outwards for text outside the circumference; and inwards for text inside the circumference. However in this case it is better to leave DTOF(1) set to zero and modify the text radial position DTRAD. See See Figure 12:28 below for

Figure 12:28. Radial Dimensions - DTOF(1) Setting - Text Inside Circumference

The Dimension Style (DSTYLE) attribute, combined with DTANG, controls the overall dimension style. Possible settings are:

DSTYLE DIMLINE

DSTYLE LEADERLINE

DSTYLE EXTERNAL

The default setting of DSTY is DIMLINE. This style shows a radial dimension line with terminators. For DFLAG DIAM this is drawn across the diameter with two terminators; for DFLAG RADI this is drawn from the centre to the circumference with a single terminator. (See See Figure 12:23 above for ) If the dimension text lies inside the circumference, then the dimension line will be gapped if the text crosses it. The position of dimension text is controlled by the Dimension Text Offset (DTOFF) attribute - see earlier in this Section.

The dimension line will be extended beyond the circumference of the object dimensioned if the text radial position (DTRAD attribute - see earlier in this Section) lies outside the circumference. If the text is horizontal, then a horizontal line will be drawn from the radial dimension line to the actual text position. Whatever the text orientation, the line will be extended to underline the text if indicated by the DTUL attribute (see below).

The LEADERLINE style shows a radial leaderline from the circumference to the text radial position. If the text is horizontal, then the leaderline will be extended horizontally to the text offset position. No dimension-line will be drawn.

Text underlining will be controlled by the Dimension Text Underlining attribute, DTUL. This indicates whether the leaderline is extended to underline the text or not. If DTUL is ON, the leaderline will always be extended to underline the text even if this causes it to pass through the text string. The line will be drawn through the text offset position - thus there will be overlining for ALIG TBODY. DTUL is ignored for DSTYL DIMLINE unless the text radial position is outside the circumference. The default setting will be OFF.

See See Figure 12:29 below for for examples of the LEADERLINE style (all shown with DTUL ON).

Figure 12:29. Example RDIMs in LEADERLINE Style

The EXTERNAL style is a variant on the Dimline style. For Diameter dimensions, two short radial lines are drawn outwards from the circumference with terminators on the circumference. If the text radial position lies outside the circumference, then one line is extended to the text offset position (with optional text underlining).

For Radius dimensions with EXTERNAL style the appearance depends on the text radial position. If it lies inside the circumference, then a single short radial line is drawn outwards from the circumference with a terminator on the circumference.

If the text radial position lies outside the circumference, then the dimension is drawn exactly the same as in the DIMLINE style except that the terminator direction is flipped to be outside the dimension line. See See Figure 12:30 below for for examples of the EXTERNAL style (all shown with DTUL ON).

Figure 12:30. Example RDIMs in EXTERNAL Style