Architectural visualisation is a powerful tool that gives architects, developers and product designers the capacity to bring nearly any concept to life–from quaint countryside villages to contemporary bathrooms. Yet, when asked, most of us probably only have a vague idea how these representations that sell millions in property, products and land are made.
To give you a glimpse of what happens behind the scenes of an architectural visualisation project, we’ve broken the process down into 6 stages.
Stage 1: Modeling
As history’s most iconic structures started as a single block of stone, so do all CGI images. From Pixar movies to bathroom sets, they all begin as simple shapes and polgons. Everything portraying 3D form on a screen is simply a map of mathematical ‘points’ which create 3D polygons. We often start with what are known as ‘primitives’ such as cubes, spheres or cylinders which are then ‘sculpted’ into more complex objects using advanced 3D modelling tools’.
These are the building blocks of what then become polygons. Polygons are the complex shapes that–when connected together–form the wireframe that gives structures 3D depth. Or furnishings, if you’re creating an interior CGI. The more numerous and smaller your polygons are, the smoother the texture of your model.
Stage 2: Lighting
Lighting is an element that can make or break an image. Unnatural lighting, at best, can make it hard for clients to appreciate details and depth. At worst, it can lead to an ugly image which may actually deter potential buyers and stakeholders. Properly rendered lighting also allows artists to control ambience and mood, further enhancing the impact of a representation.
Light does not reflect onto surfaces in a vacuum. In real life, it takes on the characteristics of the objects it bounces against, changing the way light reflects around neighbouring surfaces. Photoreal visualisation mimics this effect using an algorithm called global illumination (GI). GI looks at the way light bounces off one surface onto another. The process is integral to ensure shadows and colour are represented as the eye sees them.
Stage 3: Materials
Materials are the assets that wrap around a 3D model and communicate a surface’s colour and texture. For instance, during this stage of architectural visualisation bare panels can be transformed into polished concrete or slightly transluscent marble.
There are many ways to texture a 3D model. Architects can rely on an algorithm to procedurally create the textures, or use image maps of real photos of the materials to enhance photorealism. Some artists create materials from scratch, yet nowadays you can save considerable time with pre-existing asset libraries like textures.com. The availability of movie and game assets such as physically based materials (PBR) or 3D scans as can be seen at megascans.com
Stage 4: Dressing and Props
The basic image may be complete, but to add further interest, confirm the function of the space and demonstrate scale, extra props should be added. Much of the time, when project – specific furniture or ornaments aren’t needed, we generally head to our extensive 3D resources library. this contains thousands of fully modelled, materialised assets which can be dropped into the scene. these are 3D models in their own right, just as the scene we’re adding them to, meaning they are subject to the same lighting conditions and infinite orientations.
There are multiple resources online for obtaining 3D assets. The largest resource by far is turbosquid.com. Users can buy or upload and sell digital 3D models of anything from spacecraft and dinosaurs to real-world cars or shower fittings. Furniture manufacturers often provide 3D models of their products in ‘professional’ areas of websites. These models can often be simple and need re-modelling or ‘cleaning up’. Occasionally they are actually used as CAD in the manufacturer’s fabrication of the product, meaning they are very highly detailed and accurate. Manufacturers now realise that providing strong 3D assets is key to getting their products into high-end marketing visuals without the costs associated with traditional photography.
Stage 5: Rendering
Rendering is the stage where all geometry, lighting and material configurations and values are pulled together to create the final representation. All the images above (except the first) are actually rendered to demonstate each stage. The bulk of the job is handled by a powerful computer or several computers networked together for increased processing power (For a more detailed description of what rendering actually is, please see our post on our render farm). Depending on the final resolution needed and the cumulative processing and graphics power, it can take anything from a few minutes or hours to a day or more.
Rendering can be very time consuming and how long an image takes to render will depend on two things – the processing power of the render farms (ie how many threads it can handle) and how complex the image is in terms of realistic bounced lighting, reflections, textures and geometry (what we call ‘heavy scenes’).
To put things into perspective, to render a 4K highly detailed image on a standard home dual core intel processor would take between 15 to 30 hours. On a render farm like ours, it would take around 20 minutes.
Stage 6: Post-production
Post-production is the stage where the rendered image is brought into a 2D photoshop program to add the finishing touches. In this instance, it is simply to apply a levels and curve correction for contrast and a tint and colour balance to neutralize any unwanted colour cast. In some cases, elements such as dramatic lighting and colour editing take place to really bring the image to life. If not rendered in 3D, foliage and natural landscapes, crowds and cars can be added at this stage.
One or two people strolling down the road or a soap dispenser on the washbasin may seem incidental. Yet these elements can significantly increase the visual and emotional impact of a project. These objects help the client imagine themselves in these spaces, instead of simply being an outsider looking in at an impressive yet impersonal piece of architecture. The post-production stage is also typically where artists and designers get to exercise a bit of creative flair.