Creating the ‘A-Ha!’ Moment for Clients

Architectural illustrator Gene Corbell uses ray-traced rendering to drive home design concepts.

Corbell averages about 60 test renderings a week and three to four final renderings a month of buildings and interiors under design by Clark Nexsen, a 270-person full-service architecture, engineering, and interior design firm headquartered in Norfolk, Virginia. Corbell works with 53 architects and architectural interns throughout the firm's five offices.

Clark Nexsen designs government, commercial, retail, industrial, and academic facilities. Its work goes beyond architecture to all aspects of design, including planning, interior design, and engineering services. The company communicates its designs to clients through high-resolution, photorealistic images.

The 'A-Ha' Moment
"Sometimes clients and even architects have a hard time visualizing the final building or interior space by viewing the plans and concept sketches," says Corbell. "A photorealistic rendering of the design with all the materials and lighting helps us with our visual communication by showing how the plans are developing. It most often leads to that 'a-ha' moment, when all the ideas come together in the everyone's mind."

Corbell uses drawings or plans as the basis for building models in Autodesk's AutoCAD software. The models contain the 3D geometry of the buildings or interior space, including fixtures for exterior work and furniture for interior environments. He exports completed models to Autodesk VIZ, where he adds basic lighting, textures, and extras such as people, trees, and cars.

In the past, Corbell used VIZ's renderer to create effects such as shadows, reflections in glass, natural lighting to show the time of day, and textures for details such as pavement, stonework, grass, and fabric.

Time for Change
But rendering times were too long for Corbell. Images often had to render overnight or tied up his workstation during the day when other work required immediate attention. Much of the time, Corbell had to render an image several times to get the realistic results that Clark Nexsen requires.

In his search for a new rendering solution, Corbell came across an article about RenderDrive from ART VPS, a rendering appliance that provides accelerated ray tracing based on the real-world physics. The system, which is application independent, can provide full-frame previews in seconds, speeding up iterations for tasks such as lighting set-up, shot composition, and material mapping. It works offline, leaving the user's workstation free for other tasks.

At Corbell's urging, Clark Nexsen purchased a RenderDrive 3500 to render the models he creates. With dedicated ray-tracing chips, the new system can manage realistic effects that are traditionally expensive and time-consuming to calculate, including multiple area lights, accurate motion blur and depth of field, secondary illumination, and physically based materials, lighting, and camera properties. Corbell uses a plugin called RenderPipe to access RenderDrive directly from the VIZ graphical user interface.

Corbell says he can complete a moderate-sized image of the outside of a building, which previously took as long as 18 hours to render, in one to two hours using RenderDrive (figures 1 and 2).

Figure 1. Images such as this daylight version of an office building take only one or two hours to render using RenderDrive.

Figure 2. Gene Corbell uses RenderDrive to create realistic effects that are traditionally expensive and time-consuming to calculate, such as the multiple area lights shown in this nighttime version of an office building.

Fringe Benefits
The new system also gives Corbell greater flexibility.

"Since the RenderDrive is independent of my machine, I can work on other projects during the rendering," says Corbell. "I can also preview an image and make changes as needed without going through repeated, long rendering processes."

The new rendering capabilities have enabled Corbell to more realistically depict actual materials that will be used in a project.

"I have always used scanned textures and applied them to the models -- from building materials for exteriors to fabric and paint swatches for interior projects," says Corbell (figure 3). "But with the RenderDrive, the effects of the materials creates a more realistic image. You can get a sense of the true texture of the material."

Figure 3. This rendering of a waiting room shows how Corbell applies real-world material textures to images to achieve realistic effects.

Clark Nexsen uses Corbell's final, high-resolution images in presentations to clients, on signs posted at construction sites, and in client marketing efforts. Recently, Corbell rendered photographic-quality 3D images for several university buildings and a waiting area for a local medical facility.

As the lead 3D illustrator at Clark Nexsen headquarters, Corbell is always going to be under pressure, but increased rendering performance provides a degree of comfort.

"A great rendering tool doesn't eliminate tight deadlines," says Corbell, "but it helps me meet them without sacrificing the high level of detail our architects and clients expect."

Links
Clark Nexsen
ART VPS
Autodesk