Design Guidelines for an Interactive 3D Model as a Supporting Tool for Exploring a Cultural Site by Visually Impaired and Sighted People
Barbara Leporini, Valentina Rossetti, Francesco Furfari, Susanna Pelagatti, Andrea Quarta · 2020 · ACM Transactions on Accessible Computing · doi:10.1145/3399679
Summary
This paper presents a methodology for creating low-cost interactive 3D printed models combined with audio descriptions to enable both visually impaired and sighted people to explore cultural heritage sites autonomously. The prototype reproduces Piazza dei Miracoli in Pisa, Italy (home of the Leaning Tower), with each monument modeled as a cross-section at approximately 1 meter height to reveal internal floor plans—a key innovation allowing users to perceive spatial relationships like the Latin cross plan of the Cathedral or the octagonal layout of the Baptistery. The system uses a Raspberry Pi to manage interaction, with physically distinct buttons (circle for practical information, triangle for historical, square for architectural) placed near each building entrance. Audio tracks are organized into multiple levels of detail, allowing users to progressively access more information by repeatedly pressing the same button. Architectural details too small to perceive on the main model—such as Corinthian columns, domes, and decorative elements—are reproduced separately at larger scale on an accompanying panel and linked to the main model via the audio descriptions.
Key findings
User testing with 24 participants (8 blind/visually impaired, 16 sighted) confirmed the approach's effectiveness across both populations. All participants successfully completed seven evaluation tasks, with average completion times of 28 minutes for visually impaired users and 13 minutes for sighted users. Both groups rated the interaction experience positively (average 4.0/5 for blind/VI users, 4.53/5 for sighted users). The semantically grouped audio tracks were rated highly useful (4.62/5) and well-categorized (4.74/5). Statistical analysis found only one significant difference between groups: visually impaired users preferred a larger reproduction scale, while sighted users found the existing scale appropriate. Blind users demonstrated greater tactile sensitivity, detecting details like the slope at the tower's base that sighted users missed. A notable behavioral difference emerged: sighted users tended to skip the welcome audio instructions, later struggling to identify buttons, while blind users listened carefully from the start. The total installation cost was under $200 with 1.5 person-months of development time, making the approach highly replicable.
Relevance
This research provides actionable design guidelines for cultural institutions seeking to create accessible 3D tactile models. The eight proposed guidelines address three principles: reproducibility (simplify source models, break into printable parts), perceivability (reproduce details at larger scale, use distinguishable shapes/materials/colors for different semantic information), and understandability (add layered audio content, maintain consistency, provide clear instructions). Key practical insights include: cutting architectural models at a consistent height to reveal internal structure; using different button shapes consistently to indicate information categories; structuring audio into progressive detail levels so users control exploration depth; and including separate larger-scale reproductions of important decorative elements. The finding that tactile models benefit sighted visitors—helping them notice architectural details otherwise overlooked—supports inclusive design approaches where accessibility features enhance the experience for all users, not just those with disabilities.
Tags: 3D printing · tactile graphics · cultural heritage · museum accessibility · audio description · blind and low vision · inclusive design · tactile models · multimodal interaction
Standards referenced: BANA Guidelines for Tactile Graphics