Total Length of Selected Objects in AutoCAD

When working with AutoCAD, it's essential to have accurate measurements and calculations. One common task is calculating the total length of selected objects. In this article, we'll explore how to achieve this using a simple LISP script.

The key challenge lies in selecting entities that can be measured accurately. If you filter your selection set for allowable entity types at the time of selection, you can ensure that everything in the set will have a length that you want to add to the total. However, this approach may not work well if you also need to find Xlines, as there may be issues determining their length.

A more effective solution is to use a script that can identify lines, polylines, splines, and other entities. For example, you could reduce your filter list to include only the following types: LINE, ARC, CIRCLE, *POLYLINE, SPLINE, ELLIPSE.

If you're looking for a way to simplify your routine, consider using an alert command with a string that displays the total length of selected objects. This can be achieved by concatenating a message with the total length using the RTOS function.

For those who are familiar with LISP programming, here's an example script that calculates the total length of selected objects:

```lisp

(defun tlen (/ ss ent itm obj l)

(setq ss (ssname nil 'ss'))

(alert (strcat 'Total length of selected objects is ' (rtos tl)))

((or (= obj 'CIRCLE) (= obj 'SPLINE) (= obj 'POLYLINE))

(if (minusp (setq l (- (cdr (assoc 51 ent)) (distance (cdr (assoc 10 ent))(cdr (assoc 11 ent)))))

(setq ent (entget (setq itm (ssname ss n)))

tl (+ tl l))))

tlen)

```

Unfortunately, the famous `tlen.lsp` script no longer works in AutoCAD versions 2010 and later due to changes in the area command's behavior with polylines. However, you can still use this script as a starting point for your own custom solution.

In conclusion, calculating the total length of selected objects in AutoCAD requires careful consideration of entity types and filtering. With the right LISP script, you can automate this process and save time and effort.

Tlen lisp autocad free download