Write the reason for the third dimension
Describe one thing a visitor can understand by changing viewpoint or moving through a space that a still image cannot explain as well. A product with meaningful internal detail, a place with layers or a research structure with spatial relationships can justify interaction. If the scene only needs to establish mood, a short film may be the better production choice.
Name the audience and the next decision. Should the visitor compare objects, explore chapters, understand a mechanism or request a proposal? Give the team one representative journey with a beginning, an interaction and an exit. Without it, a quote for 'an immersive site' leaves the most expensive behavior undefined.
Inventory assets and states, not just pages
List each model, environment, texture, sound and piece of written content. Mark which assets already exist, who owns them, whether their licences permit web use and who must create the rest. Then count distinct interaction states: loading, first visit, return visit, keyboard focus, mobile controls, reduced motion and lost graphics context. One page can contain several productions' worth of work.
Ask every bidder to separate art direction, asset preparation, interface design, graphics development, content, performance work and handover. A supplied optimized model is different from a new character that requires modeling, rigging and animation. A reusable component is different from a scene whose timing must be directed frame by frame.
| Decision | Brief input | Acceptance check |
|---|---|---|
| Purpose | One visitor task and next action | The task works without replaying the intro |
| Assets | Source files, owners and licences | The agreed assets are usable and editable |
| Devices | Named phones, desktop browsers and input methods | Representative journey works on each target |
| Fallback | Reduced-motion and graphics-failure route | Essential content and action remain available |
Prototype the riskiest minute first
Build one slice with a representative asset, real copy and the actual input behavior. Test it on the least capable device in the agreed support list. This reveals asset load, scroll control, text legibility and recovery problems before the full scene is produced. Agree which degradation is acceptable and which changes the story too much.
Janus Observatory is a useful visible reference: its opening, atlas and observatory perform different jobs, with labels and explanations outside the three-dimensional layer. It demonstrates a way to keep complex material explorable. It is not a measured claim that every 3D page improves engagement, and its technical choices should not be copied without a matching task.
Sources & editorial notes
Sources
- Janus Observatory public experiencejanus-observatory.nicocerond.workers.dev
- W3C: Animation from interactionsw3.org
How we built this guide
EvidenceThis guide combines 2 linked sources, Dardo’s analysis and clearly labeled project examples.
LimitsVisible design and content decisions are not presented as measured ranking, traffic or conversion gains.
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