Floor projection
floor_projection.tox
Layer: output (image)
In: 1 TOP
Out: projection window + resolution CHOP (resX, resY)
This component is the output stage for the lab's floor projector. It works the same way as Wall projection, but for a roughly square surface with no natural "up". The floor matters in spatial computing because it is where tracked bodies, virtual objects and projected images line up most directly. A position in the room's XZ plane corresponds to a point on the floor image.
Role in the setup
The floor projection completes the lab's image output. It is especially suited to interaction based on location: zones, paths and traces that respond to where visitors stand. These are typically made by combining Azure Kinect sensors data with Virtual objects zones and Calculations.
Technical specification
- Resolution contract. As with the wall projection, the component publishes
resX,resYas a CHOP that you wire into your source TOP. - Recommended chain:
moviefilein → fit → floor_projection. A Fit TOP before the component makes sure that content made for other aspect ratios (for example wide wall content) is fitted on purpose and not distorted. - Home/lab switch. License off = reduced home resolution (within the 1280 × 1280 limit of the Non-Commercial licence). On = full lab resolution (Educational licence on the lab workstation).
- Orientation. The floor has no inherent up. By convention, orient the content towards where the audience enters (the south side, where the entrance is) and write the orientation down in the project documentation.
- Mapping to room coordinates. Because the room frame uses X = width and Z = depth, positions from the sensor and from virtual objects can be mapped to floor pixel coordinates with a linear scale to
resX,resY. This mapping is the user's responsibility, as the component does not apply it.
Parameters
| Parameter | Function |
|---|---|
| License | off = home resolution, on = full lab resolution |
| Fit Input | what happens to an image of the wrong size |
| Configure | rebuilds after settings change |
| Open Window / Close Window | opens or closes the projection |
Outputs
- Resolution CHOP:
resX,resYfor the user's source TOP. - The projection window on the floor projector.
Limitations and expected behaviour
- Wall content looks wrong: the aspect ratio is different. Add a Fit.
- Small resolution: License is off. Even at full lab resolution, the floor projector has a lower resolution than the wall projection, so avoid fine detail and small text on the floor.
- Image "upside down": the floor has no up. Orient the content towards the entrance and write it down.
- Nothing visible after a change: press Configure, then Open Window.
- Occlusion: visitors cast shadows on a projected floor. Take this into account in the content design, for example by keeping important information away from where people usually stand.
Relations
- ← any content TOP, e.g. driven by Azure Kinect sensors + Calculations
- ↔ Wall projection (same model)
- Hardware: Inventory (projection surfaces and projectors)
References
- User README: floor_projection-README
- Repository: <https://github.com/SpatialComputingL/Td-updates>
- Overview: Lab Tools