In the previous post on the Tobin Center for the Performing Arts, we covered the modeling of the Veil which clads the exterior of LMN’s renovation. Another area of pattern exploration on the TCPA is the face of the hall into the main lobby. This is a tall space and the wall has a strong presence so we wanted to create a surface that was visually compelling and intricate without distracting from the spectacle of the surrounding social activity.
The design exploration of the feature wall consisted of three scales of geometric study:
- overall shaping of the wall
- breakdown of the surface into panels
- geometric articulation of those panels
It was a fluid process where each of these three scales were explored simultaneously through the use of parametric modeling. The overall form might be adjusted in responses to changes to the interior layout of the hall or clearance issues, with the layout of the panels adapting to those changes. Studies were done exploring the shaping of single panels and then this geometry would be morphed onto the panel layout, giving us a visualization of how the panels would change across the curvature of the form. Exploring each of these scales required a fair bit of work so this post will focus only on the panel layout and we’ll follow up with a post on the development of the individual panel geometry.
The form of the lobby wall is a revolved surface defined by a S curve in section that is swept along an arc in plan. A revolved surface provides a fabrication advantage because it can be subdivided into columns running perpendicular to the arc which can then be repeated around the entire form. This means that the number of uniquely shaped panels is dependent on how many panels a column needs to be divided into for fabrication purposes.
We looked at reference patterns ranging from Southwest Native American pottery to Moorish tile patterns to the gowns worn by women during Fiesta San Antonio and even the repeating patterns of origami. What really intrigued us with some of the Moorish patterns was their ability to create a reading of nested units. We thought this effect could be used to give a reading of the pattern at both the scale of the individual panels as well as creating a larger pattern that is read across panels. The pottery examples were interesting to us because of how the basic unit of the pattern varied due to the curvature of the overall form and we thought this effect had the potential to direct a viewer’s eye across the surface. We were also trying to draw in some of the alternating texture of the exterior Veil and contrast that more rigid rectilinear geometry with the subtle curvature of the lobby wall.
Our initial attempts to synthesize these various patterns involved generating 2D sample patterns that played with scale, rhythm, and differentiation. The 2D patterns were both developed manually through typical drafting processes as well as parametrically by using Grasshopper to iterate through a simple set of parameters. Drawing the patterns in 2D was simpler than trying to draw the pattern directly on the 3D surface but it didn’t really provide us with an accurate representation of how the pattern would change with the curvature of the wall.
To get around this the 2D patterns are UV mapped onto the doubly curved, lobby wall surface. This allowed us to generate and manipulate the patterns through 2D geometric operations while visualizing them on the 3D surface. In the case of the parametrically created patterns, it was possible to hide the 2D version and look only at the 3D copy, giving the impression that we were working in 3D.
All of these patterns were based off an orthogonal grid which made locating expansion joints much easier, but we were interested in the overall pattern being less linear. Going back to some of the reference images, we liked how some of the patterns created diagonal lines of focus rather than only horizontal and vertical. We found that we could keep the corner points of the orthogonal grid in our pattern but also add a number of other subdividing points to further breakdown the grid. This lead to shapes that were extending across the original orthogonal grid, creating a level of variation that we liked.