UNESCO Project Unveiled
LightWave and LWCAD come together to re-create a UNESCO World Cultural Heritage site in the Czech Republic
Posted: Tue 10 Feb 2015
If you cannot visit the Czech Republic’s famed Villa Tugendhat in person, you can do the next best thing: visit it virtually through an interactive reconstruction created using LightWave 3D and WTools3D’s LWCAD.
When it was constructed in 1930, the Villa of Greta and Fritz Tugendhat in Brno, Czech Republic, was already considered quite special. Designed by Architect Ludwig Mies van der Rohe, the building was a pioneering monument to modern architecture in Europe. Today, the freestanding, three-story villa is a must-see structure for those interested in architectural marvels, and its unique design and construction earned it designation as a UNESCO World Cultural Heritage site. Often there is a two-month wait for tickets to tour the villa.
There is no wait, however, for the digital re-creation, which enables users to interactively explore the upper and main floors of the structure, all presented in amazing detail. The artists are working on a subsequent phase for the lower floor containing the infrastructure (air conditioning, heating, and so forth). The real-time immersive visualizations are being built by InterMoca, a Czech company formed by Robert Greenyer and Ian Childers, in conjunction with the Museum of the City of Brno.
Greenyer and Childers began the project with a number of goals in mind. Initially, it started as a training exercise for the artists at their game studio in India, with the team using publicly available images as references. But after realizing the potential of the project, they began construction anew with the goal of re-creating protected buildings and UNESCO monuments as real-time, accurate visualizations, eventually forming InterMoca based around that business model.
Creating an architectural visualization to increase skill sets for real-time presentations is one thing, but to do a precise re-creation is another, and one that requires exacting detail.
Over the course of two years the digital artists worked to reconstruct the virtual villa, using a book about the villa for reference. Three to four artists worked on the project whenever time allowed.
Unfortunately, the plans of the Villa Tugendhat depicted in the book were inaccurate. The group followed those plans, creating the model in LightWave 3D and LWCAD, which are real-world scale applications, only to find that one floor did not align with the one below it. So the group reconstructed the outline of the building to obtain the proper alignment, and then generated the textures. Because this would be a real-time application intended to run on 1GB, 2012 smart devices, a lot of time was spent developing processes that would result in a high-quality model with a very small footprint.
The workflow, in short, required the team to obtain proper source information on-site, and then do the modeling, texturing, and pre-lighting of the objects, baking of the light maps, separating the high- and low-frequency details, determining when to bake the lighting into the texture maps, then building the interactivity within the Unity game engine, where the shaders, textures, compressions, and so forth would have applied.
First, the team had to obtain resources and reference information inside the villa. Instead of using scanning equipment, Greenyer used cameras, taking a large number of photographs and video clips using a Canon 7D and a GoPro. While using the 7D, the group obtained small Raw files since they had more color depth.
Greenyer obtained principal measurements, such as key object dimensions and room heights, using a tape measure. Additionally, he would place a business card (that was a known size) in each picture to provide a scale reference.
In instances when the objects were not photographed square on, Photoshop distortion tools were used to “unwarp” the images with the reference scale applied. The group also used the Camera Raw lens adjustment tools in Photoshop, which compensated for lens distortions from the Canon 7D camera. The artists then imported the images into LightWave Modeler and scaled and positioned so they lined up with a scale model of the business card for accurate sizing.
According to Greenyer, during the early part of the development process when the project was still a training exercise, the group used LWCAD extensively because of its snapping, aligning, and scaling tools. LWCAD comprises modeling plug-ins for LightWave 3D that extend computer-aided design tools and features to LightWave users. But, with the recent improvements and streamlining of LightWave’s modeling tools, the group could do more work directly in Modeler on the second go-around than they could during the initial visualization.
In addition to size reference, the photos were used for textures. 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. For the Fritz bed, which contains a rich wood frame with a plaid covering, they used a high-resolution pattern for the fabric that was tiled onto one UV map, along with a second low-resolution color diffuse modifier map. So the first UV was the diffuse unlit color high-frequency repeating tile map texture on a color layer, while the second UV 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-frequency 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 contrast into a color lightmap that would adjust the high-frequency repeating texture component 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, this was a learning process, and most of the techniques that they developed in LightWave and Unity happened over a period of time. “Everything we needed to develop the visualization, I developed from scratch, including the lighting technique,” 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 Photoshop scripts and exported to Unity, where the textures were applied.
Although the Unity engine put up certain roadblocks, the decision to go with Unity as opposed to another option, such as the Unreal Engine, was a financial one. Presently, the architectural visualization runs on desktops (PC and Mac) and mobile (iOS, and Android) platforms.
LightWave’s Building Blocks
Greenyer is a longtime LightWave user, currently using Version 11.6. For the villa application, many of the functions he found most valuable were those that supported his technique for obtaining high-end textures and lighting with minimal expense for running in real time on 2012 smart-device hardware. For instance, the linear color space workflow helped the artists maintain the same color throughout every part of the pipeline, with predictable 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 it would in Unity.
“Another important thing was the surface baking tools. The custom cameras allowed 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 resorting to full lighting solutions, which were not practical.”
There were a number of LightWave tools that were vital to the project. FBX interchange proved invaluable, enabling the artists to transfer assets easily into Unity. “The job became less demanding over time as the LightWave FBX interchange tools improved. Now we don’t worry about that, it just works,” says Greenyer. In addition, recent improvements to the LightWave UV tools within Modeler made it easier for the artists, as “this kind of work requires really well laid out UVs,” he adds. Starting with LightWave 11.5, the software began supporting fast, one-click ABF (Angle Based Flattening) UV unwrapping, so by using edge selections for defining seams, complex UV maps could be created quickly.
Of course, the most important LightWave features were those used to generate the HDRI color maps. During this process, LightWave’s unique Viewport Preview Renderer (VPR) was used extensively as the group created photo-matching scenes, which included base textures and baked HDRI color lightmaps in GLSL shading mode on one side of the monitor to match the actual scene photography on the other.
Pilgway’s 3D-Coat was another key tool when it came to the all-important UVs, as well as for painting of the base color mapping and baked lightmap cleanup. In addition, the program was used for its retopology tools to generate more optimized meshes from higher-fidelity models in order to run better within the Unity engine. While older PCs were used for LightWave modeling, newer PCs with high-end NVIDIA graphics cards, including a GeForce GTX Titan, were employed for the texturing within 3D-Coat. A commercial RAID 5 server was used for source storage and content development.
Another important tool was the UberCam, which was “indispensable for simultaneously creating the reflection map images necessary for Unity and for LightWave,” says Greenyer. And, TrueArt’s Batch Baking Camera, a LightWave Layout plug-in, helped the speed and quality of the rendering and the workflow of all the surface-baking operations.
Running in Real time
The artists began the building project in Modeler and then moved to Layout. The villa re-creation required the use of exact architectural measurements. Because Modeler uses real-world scale units, the artists were assured that what they built would fit into the virtual environment.
Despite the impressive detail in the images, all the models were highly optimized to run in real time. This was made easier in part by the architect and the use of functionalist architecture, as well as the pre-Ikea boxy furniture, as the villa’s design is very linear with straight lines.
The mobile platforms would present the biggest challenge: The release versions had to run on OpenGL ES2, 1GB RAM smart devices. As a result, the artists had to be constantly aware of the polygon count, texture size, and rendering challenges compared to desktop machines.
One More Floor to Go
The next major development of the villa visualization is the technical level, which contains pipes and pieces of complex machinery, such as boilers and motors. For this section, Greenyer is using a highly accurate mobile 3D scanning system with real-time mesh reconstruction for model references and, later, optimized meshes. The group also hopes to make a version for the Oculus Rift or Galaxy Note 4-based headset, to further immerse the user.
When Greenyer set up shop in India and when he formed InterMoca, there was no question that LightWave would be situated at the heart of the business. “It’s extensible, there always seems to be a solution to your needs,” he says, “which is testament to its production-proven history.” Greenyer considers the stability of ownership a plus as well. “It matters to my company that there has been a steadfast rock behind the application we have invested so much time and resources in,” he adds. And then there is the added bonus of what Greenyer calls “the friendly and helpful user base” that is willing to share techniques, tools, and insight. All of this, Greenyer says, has built a strong foundation to help LightWave and its users succeed.
The visualization is available at http://intermoca.com/store/index.php. There is a free version with limited access to the villa and a nominally priced Pro version, the proceeds of which support the villa and further development of the visualization.