November 27, 2016

ACA: Interference Condition vs Subtraction in Area Calculations

For all of the work I have done with the Schedule Feature of AutoCAD® Architecture over the years, I have not done much with trying to produce accurate Space Schedules, particularly where Interference Conditions and/or Linework Subtraction is involved.

A question came up the other day about this, and I was surprised to learn that even though an Interference Condition "removes" any visible Hatch Component from a Space in a plan (Top) view, it does not have any effect on any of the reported Area properties of a Space. I did discover that using the AecLineworkSubtract command, the area removed does affect the reported area. I cannot speak to the reasons behind this, but given that an Interference Condition (SpaceInterferenceAdd command) only affects the Floor/Floor thickness of a Space, whereas the AecLineworkSubtract command removes the projected 3D volume of a selected 2D Polygon from bottom to top of a Space, perhaps that would be considered to be "by design".

Some additional notes regarding the use of the AecLineworkSubtract command:
  • As noted in the previously linked article on the AecLineworkSubtract command, associative Spaces are not affected (even though the command will allow you to select them as objects from which to subtract). See below for a partial exception when Manual offset boundaries are used.
  • The setting of the Offset boundaries property of a Space (By style, By Standard or Manual) will affect how the AecLineworkSubtract command works.
  • When the Offset boundaries property is set to By style, if the Space is not associative, the AecLineworkSubtract command will affect all of the reported Area values (Gross, Usable, Base and Net), with the offsets specified in the Space Style (on the Design Rules tab, at the bottom right) applied to the area to be subtracted as well. Depending upon the size of the offset and the dimensions of the area to be subtracted, it is possible that some or all of the area to be subtracted could be negated by the boundary offset, giving the appearance of there being no effect. If the Space is associative, then the AecLineworkSubtract command will have no effect.
  • The By Standard offset boundary option is only offered for associative Spaces, so the AecLineworkSubtract command will have no effect on Spaces with this setting.
  • When using Manual offset boundaries with non-associative Spaces, only the the boundaries that are currently set to be editable will be affected by the AecLineworkSubtract command. You can toggle the editability of a boundary using the round gray grips that appear around the location grip or by selecting the Space, right clicking and choosing Edit Boundary and then the boundary whose status you want to toggle, from the context menu.
    The All option on the context menu, only offered when all are not already enabled, will enable all four boundaries. The Reset option on the context menu will enable just the Base boundary. For an associative Space with Manual offset boundaries, only the Gross, Usable and Net boundaries can be manually edited; the Base boundary is associative to the bounding elements. The AecLineworkSubtract command will have no effect on the area reported for the associative Base boundary, but will be applied to the three editable boundaries.
Note: AecLineworkSubtract and LineworkSubtract are two names for the same command. The autocomplete function only recognizes LineworkSubtract, so if you are going to type the command name, omit the "Aec".

November 12, 2016

ACA: WALL Command

I was asked a question about the various command line options for the WALL command in AutoCAD® Architecture, and was surprised to find that the online Help does not have an article on this command. I suppose that, in recent years, most people use the WALLADD command to add a new Wall, most likely through a Tool Palette tool, Ribbon tool or the Styles Browser, but the WALL command still exists. There are other ways to execute the other options as well. The heyday of the WALL command was most likely back in the early days, before Tool Palettes and the Styles Manager (let alone the Styles Browser), but if it is good enough to remain in the program, it should be covered in the Help.
For ease of future reference, here are my findings on the command line options:
  • Add: This option is the equivalent of running the WALLADD command, and allows you to create a new Wall.
  • COnvert: Use this option to select lines, arcs, circles, or polylines and convert them into Walls. You will be given the option to keep or delete the selected linework. Using this option appears to result in a Standard-style Wall, regardless of what the current drawing's default Wall Style is. You may be better served by right clicking on a Wall tool on a tool palette which references the desired final style and then choosing Apply Tool Properties to > Linework from the context menu. (Applying a style to linework is not available from the Styles Browser.)
  • Properties: Use this option to select one or more Walls and have the Properties palette open (if closed) and display the Wall's properties. Unless you do not keep the Properties palette open all the time, this option is fairly worthless. Even if you keep it closed, selecting the Wall, right clicking and choosing Properties from the context menu is faster than typing WALL and choosing the Properties command option. It is a relic from the bad old days before the modern Properties palette, when each AEC Object had its own Properties dialog.
  • Styles: Opens the Style Manager, filtered for Wall Styles.
  • CLeanup groups: Opens the Style Manager, filtered for Wall Cleanup Group Definitions.
  • Dimension: Allows you to select one or more Walls and have AutoCAD Dimensions (not AEC Dimensions) added to it/them. The dimensions will be oriented parallel to the first Wall selected, so choose wisely.
  • Interference: Allows you to add or remove a Wall interference. If you are going to add an interference, you will need to have the AEC object(s) that will be the interfering objects in the drawing and selectable prior to executing the command. Likewise, to remove an interference condition requires that the AEC Object(s) doing the interfering are selectable when the command is run, so if any are on layers that are Off or Frozen, you will want to turn those layers On and/or Thaw them and your display settings need to have an active Display Representation that has visible graphics for those objects.
  • Reverse: Reverses the direction of one or more selected Walls. More easily done for individual Walls with the flip grip in more recent versions of the program, but if you had a reason to reverse the direction of a large number of Walls at once, do not want to maintain the location of the justification line, dislike using tools on contextual ribbon tabs or right-click menus and would rather not click on all those flip grips, one by one, the Reverse option of the WALL command is the way to go.

November 05, 2016

Off Topic: SEPTA Strike, Work Week 1

The union representing the City Division of the local transit agency, SEPTA, went on strike at midnight, Monday, October 21/Tuesday, November 1, leaving me with a six-mile walk to get to work each morning and again on the return trip. I usually try to get 10,000 steps in every day (weather and schedule permitting), but the strike has me over that before I even get to the office each morning.
Both sides in the negotiations have been feeding at the public trough for so long that they have forgotten that most of the people who provide the money that pays for their salaries and benefits through fares paid and tax-payer funded subsidies make quite a bit less in total compensation for equivalent levels of education and experience, and that those very people are the ones hurt most by their grandstanding and inability to compromise. Drive enough people away from using public transit, and there will not be any money to argue over.