Issue link: https://digital.copcomm.com/i/457057
36 cgw j a n u a r y . f e b r u a r y 2 0 1 5 the Canon 7D camera. The images were then imported into LightWave Modeler and scaled and positioned so they lined up with a scale model of the business card for accu- rate sizing. "This meant good dimensional accuracy could be obtained alongside quality textures," says Greenyer. In addition to size refer- ence, the photos were used for textures in the visualiza- tion. However, because of the restrictions in the game engine, all the texturing had to be achieved with simple layers and two UVs only in order for the piece to export from LightWave, through the FBX Exporter, and into Unity. This meant using a diffuse unlit color map (which could be a tile repeating pattern on the first UV) and a color light map. According to Greenyer, in instances where there wasn't any high-frequency data and the texture was not reused on the color UV, then the light was baked into the texture. For the Fritz bed in the visu- alization, which contains a rich wood frame with a plaid cover- ing, the artists used a high-res- olution pattern for the fabric that was tiled onto one UV map, along with a second low-resolu- tion color, diffuse, modifier map. So, UV1 was the diffuse, unlit color, high-frequency repeating tile-map texture on a color layer, while UV2 was a baked color map on a luminosity layer. "With textures in a game engine, you are ideally looking for repeating elements that do not look like they are repeating, so you have high-frequency repeating textures like patterns and grains, and low-frequen- cy detail like color casting," explains Greenyer. "I developed a technique whereby we baked the color of objects around the target object that was colored mid-gray. By doing so, we could capture the bounce light and the direct light with all the con- trast into a color light map that would adjust the high-frequen- cy, repeating-texture compo- nent colors, such as the bed fabric. It is richly detailed and to scale, but when you look closely, you have the changes you would expect from radiosity." As Greenyer points out, the project required a good amount of trial and error when it came to techniques. "Everything we needed to develop the visualiza- tion, I developed from scratch, including the lighting technique. There was no documented way to create reflection maps in the way it had to be done here, so I created cubic reflection maps for the chrome and other reflec- tive surfaces," he says. For the highly reflective surfaces, such as chrome stools and door handles, Unity- compatible reflection cube maps were initially made from specialized LightWave cameras, rendered in LightWave using Liberty3D UberCam's Skybox, and then processed by Photo- shop scripts and exported to Unity, where the artists applied the textures. Although the Unity engine presented certain roadblocks, the decision to go with Unity as opposed to another option, such as the Unreal Engine, was a financial one. There are no costs to start out, with licensing purchased at the time the project is published. "We chose Unity because we did not know if this would ever go live, since we were still negotiating [with the museum] while we were building the visualization," says Greenyer. "Also, we didn't know what platforms we would be offering this on." Presently, the visualization runs on PC, Mac, iOS, and Android platforms. D I G I T A L B U I L D I N G B L O C K S According to Greenyer, the linear color space workflow in LightWave helped the artists maintain the same color throughout every part of the pipeline, with predict- able results. Moreover, GLSL representation in the LightWave viewport ensured that when the artists matched the lighting in the application to the photo source, the final results seen in LightWave would look the same as they would in Unity. "Another important thing was the surface baking tools. The custom cameras enabled us to create the reflection maps and adjust the individual textures in HDRI to match up everything," Greenyer explains. "It was about getting fast realism without re- sorting to full-lighting solutions, which were not practical here." Also, FBX interchange proved invaluable, enabling the artists to transfer assets easily into Unity. A lot of heavy liing was done using LWCAD, which allowed for easy and accurate rail extrusion and mesh cleanup. "It really helped speed the modeling pro- cess, making it easier to obtain accurate models," Greenyer adds. Pilgway's 3D-Coat was anoth- er key tool when it came to the all-important UVs, as well as for painting the base color map and baked light map cleanup. In ad- dition, the program's retopology tools helped generate more opti- mized meshes from higher-fidel- ity models in order to run better within the Unity engine. While older PCs were used for the modeling, newer PCs with high-end Nvidia graphics cards, including a GeForce GTX Titan, were employed for the texturing within 3D-Coat. A RAID 5 server was used for RESTRICTIONS OF THE GAME ENGINE REQUIRED THE ARTISTS TO USE SIMPLE LAYERS FOR THE VARIOUS TEXTURES.