topic Re: Dynamic Block with build in array Using Lisp or block editor in Visual LISP, AutoLISP and General Customization Forum

Dynamic Block with build in array Using Lisp or block editor

anton.chmidtMDYV8 — Mon, 16 Feb 2026 08:58:42 GMT

Hi,

I need some help to finish this project. I have created a dynamic block for a stair element section view, where the user can modify the step dimensions. Now I need to find a way to copy/array the objects a user‑defined number of times. For example, if the staircase has 7 steps, the array should move upward and to the right 7 times (as shown with the red dashed example lines).

As you can see in the file, I managed to create a dynamic array (Array_Test) that almost does what I want, but I cannot lock the distance and angle of the array so that they remain constant based on other parameters. Ideally, this array would only ask for the total number of copies and then automatically calculate the angle and distance. Currently it only asks the user to pick an endpoint, which won’t work for this project. (It may seem to work now because I drew red guideline lines for you to snap to, but in a real scenario there will be no correct snap points for Array_Test.)

Requirements:

The objects should align so that the two connection points match (marked by arrows in my DWG).
The step parameters must remain editable even after the array is created, so that if there are, for example, 7 steps, the user can still adjust the rise or tread depth dynamically for all iterations.

Thank you!

Re: Dynamic Block with build in array Using Lisp or block editor

ВeekeeCZ — Mon, 16 Feb 2026 16:12:53 GMT

Possibly something like this...

(defun c:DynStairsFlight ( / e n r b a d)
  
  (if (and (setq e (ssget "_+.:E:S" '((0 . "INSERT"))))
	   (setq e (ssname e 0))
	   (setq n (getint "\nNumber of stairs: "))
	   (setq r (getpropertyvalue e "AcDbDynBlockPropertyRise"))
	   (setq b (getpropertyvalue e "AcDbDynBlockPropertyTread"))
	   (setq a (atan (/ r b)))
	   (setq d (/ b (cos a)))
	   )
    (progn
      (setpropertyvalue e "AcDbDynBlockPropertyArray_Test_Distance" (* d n))
      (setpropertyvalue e "AcDbDynBlockPropertyArray_Test_Angle" a)
      ))
  (princ)
  )

Re: Dynamic Block with build in array Using Lisp or block editor

ВeekeeCZ — Mon, 16 Feb 2026 13:31:05 GMT

@anton.chmidtMDYV8 wrote:

.... Ideally, this array would only ask for the total number of copies and then automatically calculate the angle and distance. ...

Well, number of copies is not enough. The angle needs to remain fixed. The routine only calculates the Array_Test_Distance.

Anyways, the routine above shows you how to get and set the parameters needed. You can adjust the formula as you need.

Re: Dynamic Block with build in array Using Lisp or block editor

anton.chmidtMDYV8 — Mon, 16 Feb 2026 14:44:58 GMT

This seems like an easy task to complete before we hit the limits of the Block editor/Parameter Manager table, especially since it does not allow us to set an dynamic array path based on a formula.

Ideally, the angle could somehow be calculated by the Block Editor, Parameter Manager, Lisp, or whatever solution we come up with.

The X‑offset of the next step is always equal to the Tread (in example file: 270).
The Y‑offset is always equal to the Rise (in example file: 166.7).

In an ideal situation, the Parameter Manager would calculate both the angle and the distance for the array, or we would somehow generate a invisble helper line to use as the array path.

If we cannot create an ideal solution—meaning a stable and straightforward block with a built‑in array using only the Block Editor—then could we read the values (Tread and Rise) from the block (user can point to the block ) and use LISP to copy/array the blocks instead?

Re: Dynamic Block with build in array Using Lisp or block editor

ВeekeeCZ — Mon, 16 Feb 2026 16:14:19 GMT

Ok, updated to the ideal solution.

Now it resets array angle based on Rise and Tread.

Array distance is set by that angle and number of stairs.

BTW

You can use this line to see all the properties you can easily retrieve from selected entity (a block in this case)

(dumpallproperties (car (entsel)))

Re: Dynamic Block with build in array Using Lisp or block editor

Sea-Haven — Tue, 17 Feb 2026 00:16:45 GMT

Do you really need a dynamic block ? Like 30+ years ago pick 2 points a base point and a top landing point, based on stair rules get min max Rise and run combo that is based on the country of origin stair standards.

For me AS 1657:2018, require a maximum of 18 risers per flight, with heights between 115mm–190mm and treads (going) of 240mm–355mm.

Some other stuff.

Re: Dynamic Block with build in array Using Lisp or block editor

anton.chmidtMDYV8 — Tue, 17 Feb 2026 13:47:27 GMT

Thanks for the LISP and the dumpallproperties tip.
Regarding the LISP: does it work properly for you when you change the rise or tread values?
For me it seems to work with the default values, but when I use different ones, some misalignment happens.

Re: Dynamic Block with build in array Using Lisp or block editor

ВeekeeCZ — Tue, 17 Feb 2026 14:23:31 GMT

Well, you need to fix your block definition to make work this way.