LucentMaps: 3D Printed Audiovisual Tactile Maps for Blind and Visually Impaired People
Timo Götzelmann · 2016 · Proceedings of the 18th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS '16) · doi:10.1145/2982142.2982163
Summary
This paper presents LucentMaps, a system for creating 3D printed transparent audiovisual tactile maps that work as interactive overlays on standard tablet computers and smartphones. Unlike most audio-tactile map approaches that focus exclusively on blind users, LucentMaps serves both blind and visually impaired people by combining tactile features with visual augmentation — the tablet display beneath the transparent map highlights relevant map features with light. The maps are printed using a dual-head FDM 3D printer with two materials: transparent HDglass filament for the map body and conductive PLA filament for embedded capacitive codes. These conductive codes at the map corners enable automatic map recognition when placed on a touch display — the tablet detects the four simultaneous touch points, extracts a unique map ID encoding distances between points, and retrieves the map's geographic coordinates and orientation. This eliminates complex manual registration procedures required by prior systems. The approach reconciles three technical constraints: finger tactile sensitivity (minimum 160 microns between elevation levels), consumer 3D printer resolution (20 micron z-axis layers), and capacitive touch proximity detection (map features must stay below 1.0mm elevation to register through the display). The system supports five elevation levels for different map feature types (superior areas, buildings, streets, footpaths, points of interest). Interaction includes double-tap for feature identification via text-to-speech, multi-touch for distance measurement, speech commands for filtering features by category, and GPS/compass for real-world orientation.
Key findings
A proximity touch study across 20 mobile devices (tablets and smartphones) found that all devices could detect touches through map material up to 0.58mm, and 75% could detect up to 0.99mm, establishing the 1.0mm maximum elevation constraint. A user study with nine young participants (ages 10-21, six visually impaired with 5-30% residual vision, one with 2% vision, two blind) at a regional school validated the approach. All participants successfully placed maps on the tablet, triggered automatic map recognition via capacitive codes, repositioned and reoriented maps (registration under 10 seconds), and explored maps to identify point, line, and area features. Visually impaired participants recognized the correct number of augmented point features and identified rough shapes of augmented map features. The multi-touch distance measurement gesture was successfully used by all participants. Users were enthusiastic about the automatic recognition feature and suggested integration with the BlindSquare navigation app. Material costs were remarkably low: a 10x15cm map weighing approximately 10g cost about /bin/zsh.60 in materials (90% transparent filament at ~/750g, 10% conductive PLA at ~/500g), printable on dual-head printers under . Maps generated automatically from OpenStreetMap data via the blindweb.org service, with a custom Blender 3D plugin adapting models for conductive code integration.
Relevance
LucentMaps advances tactile map technology in several important ways for accessibility practice. First, by designing for visually impaired users alongside blind users, it acknowledges the much larger population with residual vision (nearly a quarter billion people globally vs. 39 million blind) who have been underserved by tactile map research. The visual augmentation through the transparent map provides an additional information channel without compromising tactile usability. Second, the capacitive code system for automatic map recognition solves a persistent usability problem — prior systems required careful manual alignment or multi-step registration procedures that were particularly difficult for blind users. Third, the economic analysis is compelling for broad dissemination: at /bin/zsh.60 per map using sub- printers, the approach is dramatically cheaper than Braille embossers (,800-,000) or microcapsule paper systems. The use of OpenStreetMap data and open-source tools (Blender, Mapsforge) means maps of any location worldwide can be generated automatically. For practitioners, this demonstrates that consumer-grade 3D printing with inexpensive materials can produce functional assistive technology at scale.
Tags: tactile maps · tactile graphics · 3D printing · blindness · low vision · navigation · orientation and mobility · conductive filament · touchscreen accessibility · open source
Standards referenced: ISO 9241