RESONATE
RESONATE is a parametric design tool built in Dynamo for REVIT to help architects and designers optimize the geometry and material selection of outdoor music pavilion shells to improve acoustic performance and decrease embodied carbon.
While more elaborate and well funded concert venues undergo extensive and complex audio analysis and testing to assess performance, this is often done at later stages in design and may not be available to designers working on smaller budget projects, such as for performance venues in local parks or shared community spaces. With RESONATE, designers are able to quickly enter site and project specific parameters before a generative design analysis is run to construct and assess various design options for acoustic performance and predicted embodied carbon.
RESONATE generates a 3D clamshell surface, panelizes it, computes acoustic reflections from a stage source point to an audience zone, and evaluates each panel's contribution to sound coverage and sound reflection delay. Panels are color coded in the generated design based on risk of echo, with red panels indicating those hindering proper acoustic performance. Shell panel material types are also tested and evaluated, as material choice has direct impact both on sound reflection/absorption as well as embodied carbon and environmental impact.
With RESONATE, the acoustic quality once reserved for world-class concert halls becomes accessible to the community stages, neighborhood bandshells, and public pavilions that need it most.
RESONATE is intended for architects, designers, and acoustic consultants working on early-stage design of performance venues such as bandshells, music pavilions, amphitheaters, and other temporary performance structures. The tool is designed for use during schematic and early-stage design to help discern ideal dimensions and properties given basic floor area inputs by designers, and give feedback on approximate acoustical performance before more detailed software is engaged at later stages in design and construction.
Outdoor music pavilion shells are acoustically complex structures where geometry and material choice both significantly affect performance. Designers currently have little feedback during early design stages and acoustic consultants are typically brought in during later stages of design, if at all, to run full simulation tools like ODEON or CATT-Acoustic, both of which require detailed models and specialist expertise. RESONATE provides immediate, geometry-linked acoustic feedback so designers can make informed decisions about shell shape and material during the conceptual phase, before commitments are made, and at minimal to no cost, ideal for smaller-scale and community based projects. Music pavilions are meant to be a gathering space for people to collectively share and experience artistic works. RESONATE works to emphasize and improve audience experience and sustainability.
Inputs include:
- Stage depth
- Height of Pavilion at edge of stage
- Height, protrusion of canopy into audience
- Curvature stage in various dimensions
- Material type (including acoustic reflectivity, embodied carbon of standard panels)
- Panelization count
- Size of audience
Based on the inputs, either set by the designer or via the generative design analysis, 3 arcs are constructed and a panelized surface is lofted between them, creating a 3D clamshell-like structure.
The panels are created using Panel.PanelQuad, and at each panel centroid the tool will:
- Compute the incoming vector from the stage point source to the panel
- Compute the panel surface normal
- Apply a reflection formula to find the reflected ray direction from source to panel and off
- Check whether the reflected audio ray points at the audience zone (done to a point location at the audience center with a requirement of being 50% similar in orientation to a direct vector to the audience, which is generally considered a standard adequate requirement in outdoor pavilion design)
- Computes the final acoustic performance (out of 100%) based on panel material audio reflectivity potential
- Computes the embodied carbon associated with the panel type and lofted surface area
- Coverage percentage (percentage of panels reflecting toward audience zone)
- Acoustic score (coverage adjusted for material reflectivity)
- ITDG (Initial Time-Delay Gap): measured in milliseconds, reports the delay between initial delivery of sound to audience from point source vs time for reflected sound to reach audience; computed via path lengths and speed of sound; <80ms necessary to avoid echo like results, ideal ITDG is minimized to create a warmer, more intimate sound
- Average, Max, and Min all reported
- Embodied carbon (Total kgCO2e of panels given material type)
- Panel heat map (shell colored based on individual panel ITDG value, indicates which panels will create echo like effect, useful if all located in one area may indicate necessary space for design improvement)
- Generative Design also performed to help designer evaluate the tradeoffs between desired metrics, such as optimizing for a combination of highest acoustic performance, lowest ITDG, and lowest embodied carbon
This project took a significant amount of time not only to get the nodal logic and design to work, but to adjust the logic to be a meaningful approximation of acoustic performance and to ensure the bounds of inputs and options were conducive to constructing a meaningful and relatively fast generative design output.
Going forward, there are several features RESONATE could improve upon.
First, I would include second order reflections, between panels, in the calculation of coverage and ITDG to evaluate acoustic performance and echo. Second I would find another, more comprehensive way to model the audience, such as using a broader object or average across multiple point evaluations to better approximate overall perfromance rather than a 50% approximation at one central point.