Choose your Glass with GLASSPRO: Physico-Realistic Rendering

The physical properties of glass are invaluable and unequaled when it comes to the architect’s material palette. From the time of the cathedrals and the brilliantly colored stained glass that served a functional and didactic purpose, to the modernist liberation of the floor plan and the exquisitely-framed horizontal views provided by ample windows, architects have turned to glass to achieve not only aesthetic but performative conditions in their projects.

Today, Architects face an increasing array of choices in specifying and designing with glass for building facades, as glass manufacturers propose a greater variety of colors, textures and patterns than ever before. A wider range of coatings and treatments has also been developed, allowing for a finer selection of glass panes with a combination of light transmittance, reflectance and absorption to meet the needs of outstanding architectural projects. These options affect the aesthetics and energy performance of the glass, and therefore of the overall building.

Thanks to advanced calculation tools, energy performance can now be anticipated accurately, but the graphic representation of glass is still a challenge, and yet a crucial need for architects.

Traditionally, glazing would be chosen based on the perception architects get from a small glass mock-up. But the observation depends on the lighting and environmental conditions, and the process is neither fast nor efficient, as it is harnessed by production and logistics constraints. 3D modelling and computer generated renderings today complete the picture, allowing architects to make an educated guess about how the glass façade of a building will look.

But even in the best renderings, the depiction of glass remains quite inaccurate, as the rendering is not based on actual data about the lighting conditions on site or the type of glass suggested. Hence, this is not enough to choose the perfect glass for a project.  

Physico-realistic rendering is completely changing this landscape, and Saint-Gobain is proud to lead the revolution. The #1 European glass manufacturer has developed unique digital services: the Glass Pro app and Glass Pro Live.

Firstly, the GlassPro app is an application for Apple iPad which enables the user to visualize virtually all Saint-Gobain’s standard glazing products on a standard building façade.

This is not just about 3D images or photorealism. The big innovation is that the Glass Pro app embarks close to 4000 physico-realistic images, rendering the real color and physical properties, such as light transmission and reflection, of the selected coated glass. The visualization can be done under different angles, various lighting conditions (overcast or sunny), several interior design settings (with or without white/grey blinds), and urban or rural environments. Additionally, the Glass Pro app allows you to compare the aesthetics and properties of two glass products, displaying them simultaneously on the screen.

And all this is done within seconds, on your iPad.

GlasKubus scene of the GlassPro app, under sunny sky

GlasKubus scene of the GlassPro app, under overcast sky

GlasKubus scene simulating a double skin facade

This cutting edge technology is the fruit of 10 years of thorough research and continuous improvement of physics oriented 3D modelling, with real glass samples as a starting point to render the physical characteristics of coated glass products. The result is accurate predictive imaging and daylight simulation matching the real world. 

GlassPro rendering of head of the new Saint-Gobain Tower

Using the very same technology, GlassPro Live is Saint-Gobain’s on-demand service of glass facade rendering. It allows architects to appreciate the look of coated glass on their own building, as if it was real, before it’s even built! Computer graphics artists and researchers produce physico-realistic rendering with customized glazing configurations meeting the needs of the project, and integrate them into the architect’s 3D model. 

Urban Scene (standard building) of the GlassPro app, under sunny sky

Urban Scene (standard building) of the GlassPro app, under overcast sky

The new Saint-Gobain Tower was designed by the renowned Parisian architects Valode & Pistre, who tested the service while it was being developed in 2016. They wished to see what the glazing would look like before producing the mock-ups, and to visualize the effect on the building.  From the first image until the final rendering, the method for producing the images was refined step by step, to achieve more accuracy and more efficiency. Most challenging was to manage BIM’s huge amount of data in a smooth workflow between the architects’ team and Saint-Gobain’s R&D teams, extracting 3D data from Revit files and converting them into a format suitable for the rendering software. Modeling and texturizing the surrounding buildings of the soon-to-be built Saint-Gobain Tower in La Défense district were also a crucial point, to obtain accurate and realistic reflections on the façade. In total, 28 000 m2 of façade were rendered with physico-realistic images.

GlassPro rendering of the interior of the head of the new Saint-Gobain Tower

GlassPro Live proved to be an effective tool to simplify and modernize the process of choosing the appropriate glazing. This state-of-the-art technology seduced Denis Valode as being a “relevant and reliable decision-making assistant for glazing products throughout the different phases of building design and construction”. Besides, it allowed for a more economical and more sustainable approach of prototypes management, as real glazing prototypes were successfully replaced by digital prototypes. Hence, less glass actually needed to be produced, processed, transported, stored and recycled. 

After this first success, the GlassPro Live service has been adopted for iconic architectural projects by top design agencies like the Renzo Piano Building Workshop and Ateliers Jean Nouvel.

GlassPro rendering of the new Saint-Gobain Tower, done before the construction [for comparison with the picture of the tower under construction]

Picture of the new Saint-Gobain Tower under construction at La Défense, taken in September 2018.

The GlassPro app and GlassPro Live are unique services, bringing new perspectives on building design and glazing prototyping through digital simulation. Accurate predictive glass façade rendering reduces the need for physical glass mock-ups, which opens the door to a more sustainable approach for prototyping, and accelerates the decision-making process with regards to selecting the ideal glazing with the desired aesthetics corresponding to your design intention.  

Article courtesy of Saint-Gobain

icon of the GlassPro app