Monday, 10 March 2014

Revit Stair & Railing Selection


The new Revit 2013 Stair and Railing tools brought with them some tricky changes to the selection process that might catch you out.

Selection filters now have some new subcategories for stair components, stair annotation and railing components. All the new stair subcategories have been prefixed with the word “Stairs:”, which makes them easier to find in a list; new stair tags are likewise prefixed with "Stair". Sadly this logic was not applied to new railing subcategories: Top Rails, Handrails and Supports do not have a Railing prefix in the filter, so they don't show in the list in a sensible order.  In fact it can get quite confusing because we now have "Stairs: Supports" and "Supports", which are two entirely different things so you have to remember that the latter is for railings only.
When you look at a typical selection filter list the railing subcategories are jumbled up with the rest - this becomes important when you need to specifically exclude some of the subcategories from your selection (see further on).


The same naming convention is used in the properties dialog box.  At least it is consistent, if annoyingly wrong!

Railing Terminations and Extensions cannot be selected, nor do they list with separate subcategories - they are only accessible through the type properties of Top Rails and Handrails.

Visibility / Selection

Any of these railing or stair components can be Tab-Selected or selected by dragging across them.

The rules for selection/display of Railing Supports are mysterious and confusing:
  • In section and 3D views they are visible at all detail levels.
  • In plan views they are only visible in Fine detail level;
  • Railing Supports below the cut plane in plan views are visible (fine detail level only), and can be selected by dragging or tab-select;
  • Supports above the cut plane are only visible during pre-selection or selection highlight (fine detail level only);  they cannot be selected by any method except changing the view range cut-plane or going to another view on the next level up;
  • In Medium or Coarse detail level below the cut plane in plan view, they can be selected by dragging, in which case they display a pin only (no graphics);
  • In Medium or Coarse detail level below the cut plane plan view, they can be tab-selected (location by guesswork), in which case they do not display a pin but do show a highlight line at their origin (no graphics);
Medium or Coarse Detail Level

Fine Detail Level- railing supports visible

Hidden supports visible when railing is selected

 
It is important to note that railing supports can be selected even when not visible in plan - but only below the cut plane in medium or coarse level of detail.
Invisible Supports selected

Pinned Elements

If you select by dragging across a stair, you may get pins showing up on the stairs. These are actually for the Top Rails, Handrails or Supports, which are now separate sub-components (somewhat like curtain wall components) - this means that you can often get numerous confusing pins showing up on screen. This applies to new style railings on both old or new type stairs, but not old style railings.
You can also Tab-Select these railing sub-components individually.  Again, they display pins, but each behaves slightly differently (and differently to curtain wall sub-elements).

Once you have successfully selected a railing sub-component the displayed pin behaves slightly differently for each category, as described below.

Pinned Element Properties

You can unpin them to unlock and change some of the instance properties:
  • Type selector becomes available for all railing sub-categories when unpinned - so you can change the type (Type Selector grayed out when pinned)
  • Unpinned railing supports allow the "Hand Clearance" instance property to be changed
  • Type properties can be accessed and modified without unpinning them (any sub-category)
Pinned Railing Support

Unpinned Railing Support

Stair Component Properties

Stair components do not have pins, but some of their properties can be changed without editing the stairs.
  • Runs and landings allow height property changes - this will have knock on effects to adjacent components - refer to Modifying Landings
  • Stair supports may allow changes to cut properties of free ends

Sub-Category Selection Limitations

Depending on how you select elements (multiple selection by dragging across screen or tab-selecting), you will encounter some inconsistent limitations to what you can do with selected stair components or railing sub-categories:

  • Move Command (Multiple Selection).
    • If you have any pinned Railing Supports explicitly included in your selection of elements (ie, in selection filter list), it will not allow you to move the whole selection.  Therefore you have to remove the supports from your filter selection list before moving the selection.  This will surely catch out anyone but a railing expert.
    • This does not apply to Top Rails, Handrails or any stair components - whole selection can be moved even when they are explicitly shown in the selection list and pinned.
  • Move Command (Individual Selection).
    • If you individually select any stair components, they cannot be moved without first editing the stair - in fact the Move command is greyed out;
    • If you select a (railing) support, you can move it after unpinning it - within reason (beware of how much it moves - it measures up the diagonal even if you give a horizontal distance);
    • If you select a handrail or top rail, it cannot be moved even if unpinned - but it lets you try!
     
  • Delete Command (Individual Selection) 
    • Stair components cannot be deleted without editing the stair
    • Railing Supports, Top Rails and Handrails can only be deleted after unpinning them
    • Deleted Railing Supports can be reinstated by selecting the host Handrail and clicking Reset Rail, but it will reset all changes to supports on that handrail
    • Deleted Top Rails and Handrails can be reinstated by resetting the host Railing

  • Edit Rail Command 
    • Unpinning a Handrail or Top Rail seems to make no difference to allowing it to be edited - can be edited when pinned
    • However, if a pinned Rail is edited, it will flag the Handrail or Top Rail as unpinned
    • Repinning a Handrail or Top Rail will remove all edits and reset it to original state - beware, as it is easy to lose work, as you might think that the pin command will lock all your changes!
    • Likewise, repinning a Railing Support will restore it to its original location

     
  • Groups
    • If any stair or railing sub-component is explicitly selected, but its host is not selected, then the Create Group command will be greyed out and unavailable
    • In which case, you need only add the host element (stair or railing) to the selection to enable the Create Group command
    • If a railing is added to a group, all its hosted elements will go with it
    • If a stair is added to a group, its components will go with it (run, landing, support), but its railings will not be added (unless explicitly selected)
     
  • Design Options
  • The rules for adding selections to design options are subtlely  different from creating groups:
     
    • If Top Rails, Handrails or Railing Supports are explicitly selected along with their host railing they can be added to a design option
    • If Top Rails, Handrails or Railing Supports are explicitly selected without their host railing they cannot be added to a design option
    • The same rules apply to stair components
    • If a railing is added to a Design Option, all its hosted elements will go with it even if they are not explicitly selected
    • If a stair is added to a Design Option, all its hosted elements will go with it, including its railings, even if they are not explicitly selected.  This is different behaviour to creating groups

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