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Computer-generated imagery, or CGI, is a term ubiquitous across today’s big budget movies, video games and other popular media. In the field of architectural visualisation, rendering is the process that turns values into whole worlds, from entire city blocks to gleaming pieces of silverware–so realistic that the average person would have trouble telling apart real photo and digitally-fabricated world scape.

But what exactly is the magic behind the creation of imagined spaces?

What is Rendering?

Rendering is when a computer, or more commonly a series of linked computers, translate computations into photorealistic 3D images. Professional architectural visual artists will always use a series of linked computers, known as a render farm. These allow multiple processors and graphics cards to work together in unison rendering different parts of a single image all at the same time, drastically reducing wait times.

Geometry, the nature of materials, and lighting computations are all crunched so the render farm can determine the colour and texture of each pixel in the resulting image, from the reflection of morning sun in a river to the lamplight in a lounge at nighttime.

What goes into a Rendered Image?

Even the most detailed photos start with primitives: basic geometric shapes like cubes and spheres. Artists often model these structures from sketches using software like SketchUp or 3ds Max. From this foundation, the artist builds increasingly complex shapes, called polygons, connected in 3D space to create the skeleton of a building, walls, furnishings and other objects.

To bring this form to life, artists use a variety of texture maps and lighting effects, tweaking settings to get the best possible approximation of how light bounces off these objects in the real world. It’s here where elements like reflectivity and depth are introduced to make glass glint, carpets look plush or polished wood feel smooth and lustrous. The modelling software then inputs these as values and calculations when the object is rendered. Each pixel on the image is then created based on these precise calculations to perfectly capture light, shadow and texture.

Below, we see a representation of what these values look like to a computer, and how each pixel is actually made of blocks of instructions. This is what an image looks like when it’s being rendered. Even on powerful render farms, this process can take several hours.


3D artists and architects can use the immense library of textures and models that come with each rendering software to create just about any landscape, structure, or fixture. There are basically no creative limits–you can even build hyper-realistic images of snow from models of monkeys.

After creating the final draft, the 3D model is exported out as is, or superimposed against pictures of vacant lots or neighbourhoods–wherever the structure is to be built. Tools are often built with features to help line up the model with real-world pictures to increase realism.

Artists can also choose to process the finished model in Photoshop to add dramatic lighting and warmth or correct elements like reflections. Depending on your skill and hardware’s computing power, these little tweaks can be faster to make using the powerful photo manipulation tool.

What is a Render Farm?

Every little element you see in a CGI is the product of rendering, from the glint of glossy floorboards to the reflectivity of each individual blade of grass in a garden. The process, when run through your typical computer, can take several hours to complete–days, if the project is more complex.

Render farms are clusters of processing units that can cut render time significantly. At OceanCGI, we use powerful computing farms to bring time to render down to mere minutes, even for animations with thousands of frames.

Ocean CGI render farm

Ocean CGI’s beloved render farm.

What Type of Software do 3D Visual Artists use?

Architects and artists have a deep toolbox. Typically an artist will be well versed in using a variety of software for different tasks. For instance, you might use 3ds Max for modelling, V-Ray for texture and rendering, and then Photoshop for lighting effects. There are software suites that offer multiple functionalities, but even popular options may not come with rendering features more powerful than dedicated plug-ins like V-Ray.

Generally, the tools fall under two categories: renderers and modellers. Below are a few of the most popular applications.


  • Maya: One of the most advanced modelling tools on the market from Autodesk. Used by 3D artists and moviemakers alike, its powerful physics-based modelling capabilities will be helpful for architects looking to create architectural animations like fly-throughs.
  • 3ds Max: Another Autodesk-owned software, this tool is one of the most popular for modelling and texturing. 3ds Max makes the creation and sculpting of shapes easier with its robust toolset.
  • SketchUp: A favourite among beginners and independent artists for its relatively easy to use interface and free pricing. A Pro, paid version is available if you’re looking for more flexible tools. The software was acquired by Google in 2006, which gives it a unique perk for rendering photorealistic images: the ability to easily use images from Google Maps.


  • V-Ray: Developed by Bulgarian software company Chaos Group. V-Ray is a plug-in, which means it works with numerous modelling suites like 3ds Max, SketchUp, and ArchiCAD. V-Ray is best known for its deep selection of textures and lighting effects, making it a top choice in architectural visualisation, gaming, and film.
  • Corona Renderer: This tool was released a little over 4 years ago, and bought out by the same company that owns VRay. The tech is prized by established firms and independent artists alike for its usability and–compared to VRay–relatively cheaper pricing.

For more information on rendering and the architectural visualisation process and how we can use it to create jaw-dropping images for your next project, give us a call today.