Gare do Oriente - Revit Nested Repeaters - part 3

In previous posts I described how to use Revit adaptive components and repeaters to start creating a model of Santiago Calatrava's roof structure of the Gare do Oriente in Lisbon:
Part 1 - The rig for one structural column
Part 2 - Placing roof panels onto the rig

This time we will look at creating the structural elements to put on the rig.

Here is a youtube tutorial on creating the structural elements as an adaptive component, and placing the adaptive components to become a 'Repeater'

Steps

Here is a quick checklist of steps required:

• Start new adaptive family
• Place a point at the origin, plus two more points
• Make the points adaptive
• Join all three points with reference lines, ensuring that 3D snapping is ON

Add an arc between points 1 and 3;  the arc must be kept planar with the 3 points, so it needs to be hosted to a rig (or alternatively a plane - not shown here)

• Place a hosted point midway along the line between points 1 and 3
• Place a reference line from that hosted point to adaptive point 2
• Place another hosted point on that new line
• Place a reference arc by Start-End-Radius, snapping to adaptive points 1, 3 and then to the latest hosted point

Create a curved swept blend along the arc:

• Place two more hosted points close to each end of the arc

 

• Create a new profile family from a generic adaptive template (not a traditional profile family template)
• It does not require an adaptive point
• Draw a 2D profile closed shape on the level work plane - in this example a T-shape
• Dimension it and make it parametric

 

• Save and load into the first adaptive family
• Place a profile component onto each of the hosted points on the arc
• NB. The reason for hosting the profiles onto points that are themselves hosted on the arc is that it gives much better control:  The points have rotation parameters as well as parameters to control their distance along the arc - required to vary depending on the structural connections. Hosting the profiles directly on the arc would not give those controls.
• Duplicate the type of the profile component closest to adaptive point 1
• Make its dimensions larger
• Select both profiles plus the reference arc 
• Create form

• It will generate a swept blend that tapers to a smaller size towards point 3 
• NB. For more detail on this procedure, refer to my post on Adaptive swept blends

Create a simple extrusion family

• Create a new family from a generic adaptive template
• Place two points (one at the origin)
• Make them adaptive
• Place a reference line between the points 
• Host two points close to each end
• Associate their 'Segment or Chord Length' properties to parameters for offsets from ends
• Make the reference planes of the points always visible

• Set the Work Plane as the reference plane of one hosted point
• Draw a profile for the extrusion - I just made it a simple circle
• Give it dimensions and associate to parameters
• Repeat the same profile on the other hosted point

• Select both profiles and the reference line
• Create Form
• Save the family - I like to use a code to indicate it is adaptive and how many placement points
  eg:  AC 2pt Tube
• load it into the first adaptive family
• Place one of the new extrusion components between adaptive points 2 and 3
• Associate its properties to parameters in the parent family as desired
• Flex the adaptive points to check it is all working

 This structure now requires an additional placement point in a different plane to the rest

• Add another point close to point 3
• Make it adaptive (4)
• Move it down in the Z direction
• Link points 2 and 4 with a reference line (optional)
• Link points 3 and 4 with a reference line (optional)
• Place one of the tubular 2 point adaptive components between points 2 and 4 
• Place another between points 3 and 4 
• The structure family is now ready to use
• Save it and load it into the rig family created in part 1 - The rig for one structural column

Assembling the structure on the Rig

• On the rig, add a new hosted point onto the vertical reference line - this represents the springing point of the structure where it starts to curve out
• Below this will be a rectangular extrusion, to be added later
• This point will host the base of the structure adaptive components
• Change its Measurement Type property to segment or chord length
• Associate its segment/chord length to a parameter for Height of springing point

 

• If you have the roof panels already in place on the rig (Step 2), it will probably be easier if you temporarily hide them before starting, to make snapping easier.
• Place one of the support adaptive components, making sure to snap the 4 placement points onto the rig in the right order:

1. Springing point
2. Central valley hosted point on vertical line
3. Divided path point on inner circle (orthogonally, along X axis from origin)
4. Divided path point on outer circle, one division around anti-clockwise

Array a pattern around the circle using the Revit Repeater function:

• If you select just the one structural element and repeat it, you get a straightforward radial pattern - this is not what we want (so, undo it)

 

• We need to teach Revit how the array pattern should go - so you have to place a second structural component:
•  Place another adaptive component 90 degrees around the circle in the same sequence
• The first two placement points go onto hosted points that are already occupied by the first structural component - so it is vital that you snap to the host points, and not to end points or adaptive points on the component.
• Watch the prompt in the bottom left corner of the screen before each point placement - the first two should be to Point of Reference points

•  The second two should be onto Point of Divided path

• Use this technique for every subsequent placement of adaptive points - it gets progressively more tricky as you go

• Select the two adaptive structural components
• Click on the Repeater icon
• You should get the desired pattern if all adaptive points were hosted correctly.  

• If not you may be able to rehost the points (if you can guess which one is wrong!) - or just delete the adaptive component and place it again
• The next step is to place two more structural components in the reverse direction (clockwise)
• You could try placing them to the correct hosts, but it is really difficult with all those elements in the way - so it is easier to temporarily hide the repeater first
• You may find that when you hide the repeater, the nested tubular components around the top do not hide.  In which case, you need to select one, then right-click to select all instances and hide those too
• Once placed, the two new structural components will fit in the gaps between the first repeater element

• Some of the structural members will be in the same place as the original ones, so you may get a warning message about identical instances.  

• If this is an issue (for scheduling etc), then you will need to go back into the adaptive structural component and give the common elements a visibility instance parameter - back in the rig family, you can then switch off the duplicate structural members on the two newly placed components.
• Select the two new components and array them using the Repeat function
• Now the basic structure should be complete

• Try flexing the parameters for the rig dimensions to check that the structure moves with it.
• If you have the roof panels already placed, make them visible again to check that it aligns correctly

Click below to proceed onwards:
Step 4  Adding Struts to the structure
Part 5 - Assembling the Array of Structural Columns