Glossary

Architectural visualisation is the practice of producing images, animations, or interactive walkthroughs that show what a building or interior will look like before it is built. The discipline sits at the intersection of architecture, photography, and post-production craft. A good visualisation is not a picture of a building; it is a picture of the experience of being in that building under a specific set of conditions, light, season, time of day, weather, mood, and viewer position.

The work is used by architects to test design decisions, by developers to secure planning approvals and finance, by marketing teams to sell unbuilt projects, and by clients to understand what they are buying. The same source CAD model can be visualised for any of these audiences, but the choices that go into the final image (camera, lens, light, materiality, foreground composition) shift depending on which decision the image is supporting.

At 256 GRAYS, we treat architectural visualisation as a design-process tool first and a marketing artefact second. The renders that get used in a planning submission are usually not the same renders that go in the brochure, and the conversation about which is which is part of how we work.

See also: Photorealistic rendering, Virtual tour.

Photorealistic rendering is the production of a still image that is intended to read as a photograph rather than as a drawing or illustration. The defining feature is that a viewer's first instinct is to treat the image as a record of a real scene, not a representation of an imagined one. Photoreal renders are used when the goal is to remove the cognitive distance between viewer and design, so they react to the space rather than to the medium.

Technical photorealism is a combination of accurate light simulation, physically based materials, careful camera and lens choice, considered post-production, and a long list of small craft decisions about what to include and what to leave out. The trap is that a render can be technically photoreal and still feel wrong, because being a convincing photograph is not the same as being a convincing image. The best photoreal renders are also good photographs: they have a subject, a moment, a composition.

We work in photoreal as our default register because the discipline rewards architects who want to interrogate their own design rather than admire a rendering of it.

See also: Architectural visualisation.

A virtual tour is an interactive walkthrough of a 3D environment that lets a viewer move through the space, look around, and explore at their own pace. The current standard format is a sequence of 360-degree panoramic renders linked by hotspots, viewable in a browser on any device, with optional VR headset support. More recent formats use real-time engines (Unreal, Unity, web-native) for fully free movement, but the panoramic-tour format remains the most accessible and broadly compatible.

Tours are useful when a still render under-represents the spatial experience, particularly for hospitality, residential, and commercial interiors where the relationship between rooms or the sense of arrival is part of what is being designed. They are also useful for stakeholder reviews when remote participants need to understand a scheme without travelling to a presentation.

256 GRAYS produces panoramic virtual tours as a deliverable that typically follows a still render commission, using the same modelled environment as the source. Examples are at /vrtours/.

See also: Architectural visualisation.

CGI (computer-generated imagery) refers to images produced through a controlled modelling, lighting, and rendering pipeline using software like 3ds Max, Corona, V-Ray, Unreal, or similar. The output is deterministic, the inputs are explicit, and the result is constructed image by image with the operator making every meaningful decision along the way.

AI rendering refers to images produced by generative AI models (Midjourney, Stable Diffusion, ChatGPT image generation, Vizcom, and others) that synthesise an output from a text prompt, a reference image, or a rough sketch. The model makes most of the meaningful decisions; the operator influences direction through prompting and iteration.

The two are not the same craft, despite producing visually similar outputs. CGI gives the architect (and the studio) control over every element of the final image, which matters when the render is supporting a design decision or a planning submission where accuracy is contractual. AI rendering is fast, suggestive, and often visually striking, but the output is fundamentally interpretive rather than constructive: the model is filling in gaps based on what looks plausible, not what is true to the source design.

For early concept exploration, AI rendering is often the right tool. For renders that need to be defensible against the actual design, CGI remains the right tool. The choice is a question of what the image is for.

See also: Architectural visualisation.

A render pass is a single output layer from the rendering engine that isolates one aspect of the image: the raw beauty pass (the photographic-style colour image), the ambient occlusion pass (the soft shadows in corners and crevices), the depth pass (distance from the camera, used for atmospheric effects), the alpha pass (the masked silhouette of the rendered elements against the background), the various light passes (separating the contribution of each light source), and more.

Post-production is the stage after rendering where these passes are recombined and adjusted in Photoshop or a similar editor. Colour grading, atmospheric haze, foreground elements, sky replacement, and subtle composition tweaks all happen here. A skilled post-production stage can take a competent render and turn it into a memorable image; a poor post-production stage can flatten a great render.

256 GRAYS treats post-production as a craft stage in its own right, not a final touch-up. Render passes are kept as deliverables on request, so clients with their own in-house post-production teams can take over from the rendering stage and make the final image their own.

See also: Photorealistic rendering.