About Variable Curtain Walls

Variable Curtain Walls offer more control over the design of curtain walls than the Curtain Wall feature. You can model variable curtain walls using horizontal bands, vertical bands, and regions. Each band and region can have a unique pattern.

The following topics are discussed:

This page discusses:

Bands and Regions

You can subdivide a variable curtain wall using horizontal and vertical bands, which demarcate regions within a variable curtain wall. For example, in the image below, the regions are highlighted in blue, horizontal bands are highlighted in red, and vertical bands are highlighted in yellow.

Horizontal Bands and Vertical Bands

You can create horizontal bands using a horizontal plane as a reference. The system places a horizontal band where the reference plane meets the variable curtain wall face.

You can create a vertical band by using a point as a reference. The system places a vertical band where the reference point is projected to the baseline of the variable curtain.

While horizontal bands are always parallel to the ground plane, vertical bands may not be strictly vertical. The orientation of a vertical band depends on the geometry and orientation of the host face.

Row and Column Offset

You can create offset patterns in a region or band.

  • Row Offset: You can create a horizontal running bond pattern in a region or horizontal band by applying a row offset. The system applies the row offset distance from the blue anchor line to alternating rows of a region or horizontal band. In the image below, a row offset is applied in the yellow horizontal band.

  • Column Offset: You can create a vertical running bond pattern in a vertical band by applying a column offset. The system applies the column offset distance from the blue anchor line to alternating columns of a vertical band. In the image below, a column offset is applied in the yellow vertical band.

Mullion, Panel, and Surface Offset

You can offset mullions, panels, and the variable curtain wall itself from the host surface.

  • Mullion Offset: You can offset the mullions from the host surface of the variable curtain wall. Mullion offset is measured perpendicular to the panel, away from the building mass. Negative values flip the direction of the offset.

    For example, in the image below, the mullions are highlighted in blue. Both the horizontal and vertical mullions have a depth of 0.5 meters. But the horizontal mullions are offset by 0.5 meters from the host surface, while the vertical mullions are not offset.



  • Panel Offset: You can offset the panel from the host surface of the variable curtain wall. For example, in the image below, the panels highlighted in aqua blue are offset by 0.5 meters from the host surface.

  • Surface Offset: You can offset the entire variable curtain wall from the host surface. You can also create multiple variable curtain walls on the same host surface. For example, in the image below, the brown curtain wall is hosted on the same surface as the previous curtain wall, and offset by 1 meter. You can use multiple variable curtain walls to create a multilayer curtain wall or a rain screen.

Make Unique, Make Similar, and Match

A region may have a unique pattern definition or share the same pattern definition with other regions. By default, all regions in a single variable curtain wall share the same pattern. For example, if you change the mullion pattern in one region, all the other regions in the variable curtain wall reflect the change in the pattern. You can use Make Unique to create a pattern definition that is unique to a single region. You can use Make Similar to share a pattern definition across multiple regions.

Regions, horizontal bands, and vertical bands do not share pattern definitions with each other. Region pattern definitions may only be shared by other regions. Horizontal band pattern definitions may only be shared with other horizontal bands, and so on.

You can use Match to copy a pattern definition from one region to another, even copy from a region in a different variable curtain wall. Match creates unique pattern definitions for both regions, while Make Similar shares the same pattern definition between two regions. The same is true for horizontal and vertical bands.

You can use Match to make a copy of an existing variable curtain wall on a new host surface. The system copies the maximum number of pattern definitions, including horizontal bands to the new variable curtain wall. Vertical bands are not copied.

You can use Match to make a copy of an existing variable curtain wall on the same host surface. You can then offset the copy from the surface to create multilayer curtain walls or rain screens. Horizontal bands, vertical bands, and pattern definitions are copied to the new variable curtain wall.

Overlapping Bands

When horizontal bands and vertical bands cross, one band overlaps another where they cross. By default, new bands are created over existing bands. You can use Bring to front or Send to back on a band to change the order of overlap.

Region Keyboard Navigation

You can use the keyboard arrow keys to navigate and highlight regions and bands in a variable curtain wall. You can press Enter to activate the selected region or band.

Modeling of Variable Curtain Walls

Each region and band in a variable curtain wall contains two bodies; a mullion body and a panel body. Mullions are sweeps that optionally can be joined together to create cleaner intersections. Panels are modeled as a single surface per region.

Each region and band pattern definition has unique settings for mullion and panels. You can set the width, depth, and offset of horizontal and vertical mullions. You can set the thickness and offset of the panel. You can also control the color and transparency of mullions and panels for each unique region or band pattern definition.

Placement of Variable Curtain Walls

Pattern definitions within regions and bands have a horizontal and a vertical anchor. While editing a variable curtain wall, when a region or bands is active, the blue line represents the anchor position. For horizontal bands, the anchor positions can be left, center, or right. For vertical bands, the anchor positions can be top, middle, or bottom. The blue anchor line may be offset from these anchor positions. Offsetting the blue anchor line of a band may shift the location of the band relative to the reference plane or point. The start of the pattern may also be offset from the blue anchor line.

While editing a variable curtain wall, when a region or band is active, the yellow lines represent pattern definition lines. These lines get repeated across the surface. You can drag the yellow line to change the distance between neighboring mullions in the active region or band.



While editing a variable curtain wall, when a region or band is active, the green lines represent the repeated pattern lines. You can click a green line to turn it into a yellow pattern definition line.



Variable Curtain Wall Properties

You can set variable curtain wall properties that affect the entire curtain wall area.

  • Isoparametric vertical mullions: By default, vertical mullions follow lines that are formed by vertical plane cuts. You can instead have vertical mullions follow isoparametric lines on the curtain wall surface.
  • Horizontal mullions parallel to ground: By default, horizontal mullions are normal to the host surface. You can instead have horizontal mullions parallel to the xy plane.
  • Merge triangular cells: A curtain wall pattern may create triangular panels where vertical mullions meet an angled border. You can avoid creating triangular panels by merging them to the neighboring panel.
  • Join mullions: By default, horizontal and vertical mullions overlap each other on the variable curtain wall surface. You can join mullions to create cleaner geometry and improve the visual appeal of the curtain wall. Joining mullions increases the build time for the curtain wall, and therefore impacts system performance.
  • Mullions at cutouts: You can create mullions at the edges produced by doors, windows, openings, glazed panel walls, and other cutouts in the host surface. The widths of horizontal and vertical mullions at the edges of cutouts are the same as that of other horizontal and vertical mullions respectively in the region.
  • Opposite side: By default, the variable curtain wall is created on the surface away from the building mass. You can instead create the curtain wall on the opposite side of the hosting surface.