9 minute read
The path towards Simulation-Based Architectural Design
Rhys Goldstein, Principal Research Scientist, Autodesk Research
Kean Walmsley, Platform Architect & Evangelist, Autodesk Research
Advertisement
Divyae Mittal (Student, M.Sc in Building Technology, Faculty of Architecture, TU Delft)
Introduction
In the future, a large selection of computational analyses will be readily available to evaluate designs based on various measures of human experience. Computers will help designers answer questions such as the following. How will people experience a built environment? How will they travel from one place to another? What will they see? What will they hear? How much daylight will they be exposed to at various times of the day? Will they be comfortable? Will they be healthy? Will they have privacy when appropriate? Will they feel socially engaged when appropriate? Computer-generated insights pertaining to human experience will increase architects’ awareness of the tradeoffs between one design and another, hopefully preventing the most user-unfriendly designs from being built. The same technology will allow designers to consider a far greater diversity of options than is currently possible, which should lead to better environments and improved wellbeing. New space analysis tools are already starting to change the design process. Yet these tools only scratch the surface of what is to come. As the analysis of human experience begins to incorporate the time dimension and systems modeling approaches, architectural design will become a largely simulation-based discipline. Here we’ll explore this transition by looking at a few projects led by Delft University and Autodesk Research.
From Space Analysis to Simulation-Based Design
By Rhys Goldstein and Kean Walmsley
Currently, efforts to quantify human experience in built environments tend to focus on geometrical analyses, ignoring the dimension of time. A well-known example of such an analysis is the isovist, the region of space visible from a single point. The name isovist comes from the space syntax community, which has pioneered a wide range of analyses based on the geometry of building floor plans and urban neighborhoods. As of the past few years, isovists and other spatial analyses have been used to compute metrics for generative design projects, a notable example being the layout of Autodesk’s Toronto office. In this project, the arrangement of meeting rooms and working areas was suggested by a computer in order to minimize visual distractions and maximize views to the outside, among other goals.
Figure 1. Autodesk’s Toronto office is an example of generative design based on spatial analyses. The arrangement of meeting rooms and working areas was suggested by a computer to meet several objectives, such as maximizing views to the outside.
To help architectural researchers and designers pioneer their generative design workflows, Autodesk Research recently developed the SpaceAnalysis package for the Dynamo parametric design tool. SpaceAnalysis performs pathfinding, visibility, and acoustics analyses from which various experience-related metrics can be computed. The tool uses a grid-based approach for all three types of analysis. Travel barriers, visual barriers, and sound barriers such as walls and columns are represented by severing connections between neighboring grid points. This results in a lattice suitable for various types of calculations. The grid-based approach makes it easy to feed geometry into the SpaceAnalysis tool and interpret the data that comes out.
Although much can be achieved by analyzing space alone, certain human experiences can only be fully captured through the simulation of scenarios involving events that unfold over time. For example, analyzing travel paths can give one a sense of which areas in a building may become congested. Yet to confidently predict when and where crowding will occur, and how severe it will be, it is necessary to simulate people moving through a building over time. Crowd simulation tools exist and are used to design transportation hubs and analyze building evacuations.
Figure 2. An example of pathfinding and visibility analyses produced in Dynamo using the SpaceAnalysis package.
But there is a wide range of human experiences that emerge in all types of built environments as people go through their day-to-day activities. Most day-to-day scenarios are not captured by existing simulation tools, and designers are not always aware of the impact of their designs on the human experience. Incorporating time is the next step in the progression toward simulation-based architectural design.
Figure 3 (Bottom). Example of day-today activities being simulated over time. The simulation shows customers (yellow) and employees (purple) moving through a hypothetic hotel. Green glowing effects indicate windows being opened to cool the indoor environment.
Systems Modeling for Built Environments
By Rhys Goldstein and Kean Walmsley
Buildings and cities should be regarded not as physical structures, but rather as systems that continuously progress from one state to the next. The design should account for processes such as human perception and decision-making, weather, light, thermodynamics, sound, transportation systems, and building control systems. If computers are to help a designer analyze a built environment as a system, we must be able to simulate these types of processes and the interactions between them.
Simulations are often developed in an ad-hoc manner. One starts by modeling one aspect of a system, then adds another aspect, and another, and another. Every time a new aspect is added to the simulation, the code becomes more complicated and difficult to work with. Before long, the simulator becomes so unwieldy that no one is willing to enhance it further. Progress slows to a halt, and eventually, someone decides to rewrite everything from scratch. And then the process repeats.
To help researchers move beyond ad-hoc practices and adopt a more scalable approach to simulation development, Autodesk Research has been investigating modeling theories that date back to the 1970s. On such theory is the Discrete Event Systems Specification or DEVS. The main insight behind DEVS is that more-or-less all simulations involving the advancement of time can be represented in a common form. This form is essentially a state machine, except that the state is augmented with time variables.
In an effort to make the theory easier to interpret, researchers at Autodesk designed a symmetrical version of DEVS involving four types of ports and four types of event handlers. Two of the ports are flow ports, which are similar to the ports used in dataflow visual programming tools like Dynamo and Grasshopper. These ports are associated with event handlers that are executed at the beginning and end of a simulation. What distinguishes DEVS from dataflow programming are the two message ports and their associated event handlers. They work as follows:
1. messages from other models trigger unplanned events;
2. time variables within the model are used to trigger planned events;
3. planned events can send messages to other models.
This mechanism allows communication between simulation models to be coordinated by a single modelagnostic simulator.
Figure 4. This symmetrical version of DEVS is intended to provide a common form for all simulation models.
The vision is to have different experts work on models of people, models of weather, thermodynamics models, control system models, etc., then connect the different models together and simulate entire buildings or urban communities. At Autodesk Research, we wanted to make this systems modeling approach available to the architectural research community, so we developed an open-source framework called SyDEVS. The framework allows people to implement models in our symmetrical version of DEVS, connect them, and run simulations. SyDEVS is written in C++. It is available at https://autodesk.github.io/sydevs/.
Case Study: Distraction in Office Environments
By Divyae Mittal
Studies show that humans typically spend 87% of their lifetime indoors. Half of this time can be considered spent at institutions like schools, offices, and leisure places. Thus, it is quite clear that the experience of occupants in these institutions plays a vital role in their productivity and performance. One such example is the modern workspace. In the last 50 years or so, there has been a rise in the number of open-plan offices. This rise is attributed to increased financial returns associated with that type of space. At the same time, these offices are also considered very distracting and noisy.
Figure 5. The view of the selected case study.
Source: Author
An often-cited reason for these distractions is noise due to employee interactions and movement. The evaluation of such a problem is done right now through a postoccupancy survey, which makes it difficult to make any design changes due to the high cost involved in later design stages. So, what if we can predict the user experience of the space in the early design stage? What if we can analyze the spatial layout considering user movement patterns, personalities, and reactions?
In a graduation thesis project at the Faculty of Architecture, TU Delft, Divyae is trying to develop a simulation workflow by combining SyDEVS, SpaceAnalysis, and an acoustical simulation package with studies of environmental psychology. The recent development of agent-based modeling allows such evaluations to be performed, using pre-existing data and theories from psychological researches at an early design stage. Each agent is given behavioral traits or rules according to collected data, and simulation is performed to study patterns and cumulative results that may arise during the actual use of the space.
The pathfinding component of the SpaceAnalysis package is used to trace possible paths for the employees in the office layout. The paths are used in the SyDEVS framework to perform user movement. The studies about human perception to sound, the interaction between employees, and the reaction to the disturbance provide a logical framework to perform the simulation using cause-effect loops.
Figure 6. Case Study with the paths analysis of occupants from different work desks to meeting area and pantry area.
Thus, the simulation workflow, which now takes only movement and sound into account, holds the possibility of extension into aspects like energy modeling, environmental analysis, and thermal behavior of users. Systems modeling frameworks like SyDEVS, combined with SpaceAnalysis tools, will provide architects with a way to study their designs through the simulation of different scenarios and activities.
About Authors:
Rhys Goldstein is a simulation expert at Autodesk Research who specializes in modeling paradigms, visual programming, and applications of simulation to architectural design. His main interest is helping designers create more compelling and sustainable urban environments by modeling buildings and cities as systems. Rhys is the lead developer of the SyDEVS framework and was part of the team that created the SpaceAnalysis package for Dynamo.
Kean Walmsley is a platform architect and evangelist working for Autodesk Research. He blogs and tweets about developing with Forge, AutoCAD and other Autodesk technology, especially with respect to the Internet of Things, Generative Design, Virtual Reality, and Augmented Reality. Kean co-developed the SpaceAnalysis tool and has written extensively about its use.
Divyae Mittal is a master student pursuing Building Technology track at Faculty of Architecture and Built Environment, TU Delft. He is primarily interested in improving user experiences in the built environment through modern technology. He is trying to make it possible by combining knowledge of computational design, simulation, and psychology.
