FCS Configurator and Parametric-Design Patterns

This document covers multi-file parametric-architecture patterns: gclass/gblock composition, distributions, deep-parameter hierarchies, constraint triggers, and the .fcc project folder structure.

1. Single-File Component (GClass / GBlock)

The most basic unit of reuse is a gclass + gblock pair.

# define the reusable component type
gclass {gcFence} filename "fence.fcs"

# instantiate with a local coordinate system (LCS)
gblock {gbFence1} gclass {gcFence} lcs { Origin={0,0,0}, Axes=GCS.Axes }
gblock {gbFence2} gclass {gcFence} lcs { Origin={5,0,0}, Axes=GCS.Axes }

Inside fence.fcs the geometry is authored in the local frame. The lcs transforms it to world position.

Parameter passing

gclass {gcWeight} filename "weight.fcs" parameters { H = T, B = T }
gblock {gbW1}     gclass {gcWeight} lcs { Origin={0,0,0}, Axes=GCS.Axes }

Variables in weight.fcs receive the values from the parameters { } block.

2. gblock … if (condition) — Conditional Placement

A gblock is only instantiated when the condition is true:

gblock {gbWindow} gclass {gcWindow} lcs { ... } if (buildingHasWindows)

This is the primary mechanism for optional geometry — openings, add-ons, accessories.

3. Distribution — Repeated Parametric Elements

distribution creates N copies of a gclass along a path, with per-instance parameter overrides.

distribution {dColumns} gclass {gcColumn}
    lcs { Origin={0,0,0}, Axes=GCS.Axes.Ry(-PI/2).Rx(PI/2) }
    transformation translation direction {1,0,0}
    repetitions spacings (columnSpacings)
    specialization ithparameters {
        ith 0 parameters { CssHead:= { h:=0.34 }, CssEnd:= { h:=0.54 } },
        ith 1 parameters { CssHead:= { h:=0.30 } }
    }

Source files

• TestData/new-Speed2/Configurator_SheatedBuildings_Structure/PrimaryFrame.fcs
• TestData/UnitTestsKnowledgeBase/examples/parametric-warehouse/PortalFrame.fcs

4. simpleRepresentation — LOD Switching

A coarser "view" of a component is shown at lower zoom levels. Declare it inside the gclass file:

simpleRepresentation {srFence}
    curve {cSimpleLine} vertex {v1} {v2}

The 3-D geometry is hidden when the viewer switches to simplified mode; only simpleRepresentation entities are rendered.

5. Constraint / Trigger System

Parameters in FCS can enforce consistency through constraints. A constraint fires when a watched variable changes and re-evaluates the target variable.

# Constraint: keep array length = SOA_N
SOA_N_trigger := {
    Constraints := [
        SecurityOpeningsArray_constraint_SOA_N
    ]
}

SecurityOpeningsArray_constraint_SOA_N := {
    Variable  = "SecurityOpeningsArray",
    Condition := (SecurityOpeningsArray.Count == SOA_N),
    Init      := SecurityOpeningsArrayUpdate,
    Explanation := "Number of openings has been changed"
}

# Update lambda: grow or trim the array to match the target count
SecurityOpeningsArrayUpdate := (
    (SecurityOpeningsArray.Count == SOA_N)
        ? SecurityOpeningsArray
        : ( (SecurityOpeningsArray.Count > SOA_N)
                ? SecurityOpeningsArray.Take(SOA_N)
                : SecurityOpeningsArray +
                  (SOA_N - SecurityOpeningsArray.Count) * [NewDefaultWindow(3.0, PrototypeWindow)] )
)

The three fields of a constraint object:

Source file

TestData/new-HiDumbbell.fcc/FenceGlobal.fcs

6. Deep-Property Paths in _updated.fcs

In an .fcc project the entry-point file *_updated.fcs initialises the parametric model's property tree. Deep properties are set with dotted paths and array indexing:

# from benchmark-HBC-2/Buildings.fcc/BuildingsComponentMain_updated.fcs
site.definitionBuildingsBase[0].inWidth_m            := 24
site.definitionBuildingsBase[0].inLength_m           := 48
site.definitionBuildingsBase[0].inEaveHeight_m       := 6
site.definitionBuildingsBase[0].inRoofPlaneSlope_per := 10

# nested array element (LINQ-object constructor inside array literal)
site.definitionBuildingsBase[0].inRoofPlaneProperties_CtArray := [
    RoofSectionSegmentInput{
        inRoofPlaneSlope_deg=10,
        roofSlopeMultiplierId="upwards",
        inRoofSlopeInputMethod="percent"
    }
]

# key-value shorthand (string value)
site.wallSheetingInput.pur.inColorSchemeVertical := "singleColor"

Rules:

• Use site. prefix for all building-level properties.
• Use [N] for zero-based array indexing.
• String values use double-quotes "...".
• Numeric units: _m = metres, _mm = millimetres, _deg = degrees, _per = percent.

7. _viewAll.fcs — Component Entry Point

Each .fcc folder has a pair of entry-point files:

The _viewAll.fcs file typically just imports the main component script:

# _viewAll.fcs (minimal example)
import "BuildingsComponentMain.fcs"

8. placeableItem2 — Insertable Component

Some gclasses are declared as placeableItem2, meaning the UI allows a user to drag and drop them at a pick point:

placeableItem2 {pi1}
    gclass {gcDoor}
    pickPoint {0, 0, 0}
    normal    {0, 1, 0}

This declares the insertion origin and orientation for interactive placement.

9. Expert-System Rule Propagation (fcsdrs)

Per-instance display configuration is stored in .fcsdrs / .fcsdrv resource files and loaded via gblock fcsdrs:

gblock {gbPanel} gclass {gcPanel} lcs { ... } fcsdrs ("panelStyle.fcsdrs")

The .fcsdrs file contains style assignments (colors, visibility flags, layer overrides) that are merged with the gblock's geometry.

Source folders

• TestData/new-GBlockFcsdrs/
• TestData/new-GBlockFcsdrs2/

10. _resources.fcs — Shared Resource Registration

In a multi-file project, one file (often _resources.fcs or Resources.fcs) defines all shared materials, section libraries, and helper gclasses. All other files import it:

# Resources.fcs
res := Resources{}     # singleton pattern

# PrimaryFrame.fcs
res := Resources{}
# ... use res.cssLib.mySection, etc.

The {} trailing brace allows parameter overrides when needed.

11. Quick Reference

# Basic gclass/gblock
gclass {gcX} filename "X.fcs" parameters { P1=v1, P2=v2 }
gblock {gbX1} gclass {gcX} lcs { Origin={x,y,z}, Axes=GCS.Axes }
gblock {gbX2} gclass {gcX} lcs { ... } if (someCondition)

# Distribution
distribution {dX} gclass {gcX}
    lcs { Origin={0,0,0}, Axes=GCS.Axes }
    transformation translation direction {1,0,0}
    repetitions count 5

# Constraint trigger
trigger := { Constraints:=[{ Variable="V", Condition:=(V==target), Init:=updateFn }] }

# Deep property path
site.subObject[0].propertyName_m := 12.5

12. Relevant Test Folders