Growth Opportunity Area: 3D Prototypical Transit Village

The sequence of public meetings, workshops, charrettes, and open house were crucial in establishing the information baseline and the stakeholder trust – fundamental to successful community engagement. The critical questions and development principles that emerged from the “Where Do We Grow?” and “How Do We Grow?” exercises framed the community’s choices for alternative density scenarios, the concept of Growth Opportunity Areas, and the rating of the visual simulations – “building blocks” – that illustrated urban design possibilities from the neighborhood to the village center. To ensure that the consensus achieved on the development scenarios that would form the core of the Kona Community Development Plan was fully understood by all of the stakeholders, a 3D Digital Model of a Prototypical Transit Village was created by assembling the community’s preferred “building blocks.” The Growth Opportunity Area, visualized in the 3D Prototypical Transit Village, synthesized the community’s choices and preferences up to this point in the consensus building process- the vision all stakeholders could actually see and experience, before recommending the plan for approval by the county.

The 3D Prototypical Transit Village provided a means to understand what exactly is meant by walkable, mixed-use, mixed-income, and mixed-density villages. While many planners use photographs from other communities to illustrate these concepts -- visual preference surveys, for example -- a more compelling approach, and one that seems to produce a higher level of comfort for citizens, is to illustrate these concepts in a real time 3D model that uses local building typologies. Real-time 3D simulation also increases the level of trust because citizens are free to move through the simulation as they wish, on their own paths and own pace, rather than a pre-recorded fly-through. In addition, linking the 3D model to a GIS database adds a level of confidence that the density shown visually is, in fact, the stated density.

Illustrating an entire Growth Opportunity Area, with miles of roads, hundreds of buildings, and all the associated features, such as vegetation, cars, and pedestrians – would be a laborious for any 3D modeling technician. And even before the model could be built, an architect or planner would have to design the entire neighborhood. To assist planners in the process, the Environmental Simulation Center has developed a number of tools and techniques described below.

The Design and 3D Model Process

Typically, the planner would sketch out a rough road layout and blocks, sizing the blocks to accommodate certain types of units at different densities. Although the overall target average density for a Kona Growth Opportunity Area was 8 units per acre (net), this did not mean that every block was 8 units per acre. Residential densities and housing options in the Growth Opportunity Area needed to be varied to accommodate different lifestyle choices, incomes, and stages of life. The community supported more mixed-use development, requiring a blend of commercial properties and residential uses.

In the design process, the Environmental Simulation Center often uses CommunityViz® to inform the designer as she is sketching, rather than measuring areas and calculating densities and impacts after the fact. At the schematic level, different areas are drawn and designated for different land uses and different densities – ranging from 2 – 36 dwelling units per acre (see illustration). As each polygon is drawn on the map and designated for a particular density, CommunityViz® calculates the total amount of land used, the number of dwelling units, and the gross and net residential densities on the fly. This allows for accurate and relatively quick alternative scenario generation.

The design for the prototypical development area that was selected to be modeled in 3D consisted of hundreds of building and miles of roads and sidewalks. Kona also has sloping terrain and vegetation that would need to be modeled as well if the 3D simulation was to look like the actual place. Fortunately, many 2D GIS map features of terrain and roads were able to be used to parametrically generate corresponding 3D models. Representative models of other objects, such as trees and buildings, were placed in the 3D scene, having been added to the GIS map. Generating the 3D scene from the GIS database assured that 3D simulation was backed by actual data and was similarly quantifiable. The result was that the final model captured the look and feel of Kona, and accurately depicted the density of a compact and walkable transit village. It was a very large 3D model, and pushed the technology of the time to its limits. The tools and techniques were only appropriate for planners with a high skill level in GIS and 3D modeling. In the end, the technology proved to not be reliable enough for real-time design charrettes. The work that lies ahead will involve a series of plugins for 3D modeling software and CommunityViz® that automate some of the more difficult techniques used to build the Kona model. These will vastly improve the workflow process so users don’t have to be GIS experts in order to create accurate, information-rich real-time 3D models.