Lenticular Objects: 3D Printed Objects with Lenticular Lens Surfaces that Can Change their Appearance Depending on the Viewpoint

Title of the Paper

Lenticular Objects: 3D Printed Objects with Lenticular Lens Surfaces That Can Change Their Appearance Depending on the Viewpoint

Paper Information

• Field of Study: Human-Computer Interaction (HCI) and 3D Printing Technology
• Keywords: Multi-material 3D printing, optics, lenticular lenses, design tools, viewpoint-dependent appearance
• Source: The 34th ACM Symposium on User Interface Software and Technology (UIST '21)
• Authors: Jiani Zeng, Honghao Deng, Yunyi Zhu, et al.
• Conference Date: October 10–14, 2021

Research Background and Problem Statement

• Problems and Challenges:

  • Current lenticular printing technology is primarily limited to 2D media (e.g., advertisements and artworks).
  • There is a lack of techniques to create lenticular lenses and high-resolution color patterns on complex 3D surfaces to achieve viewpoint-dependent appearances for 3D objects.
  • Existing 3D printing technologies face limitations in resolution and material selection for manufacturing optical components (e.g., lenses) and high-resolution color patterns.

• Significance of the Research:

  • Dynamically displaying viewpoint-dependent content on 3D object surfaces can bring new possibilities to product design and interactive interfaces.
  • The rapid development of multi-material 3D printing offers new opportunities for realizing this technology.

• Motivation and Related Work:

  • Traditional 2D lenticular images are primarily used to display depth effects or perspective-changing visual effects but cannot be extended to 3D surfaces.
  • Existing studies have explored 3D-printed lenses, optical fibers, and other optical components, but have not achieved lens-based dynamic display functionality on complex 3D geometric surfaces.

Proposed Solution

• Method Overview:

  • Propose an end-to-end design and manufacturing process that allows designers to create 3D objects with lenticular lens surfaces, capable of displaying different images depending on the viewing angle, using 3D printing.
  • Provide an interactive 3D editing tool that enables designers to define multiple viewpoints and assign corresponding texture patterns.
  • Develop a software pipeline to automatically generate lens distributions and underlying color patterns, with one-click export for multi-material 3D printing.

• Innovations:

  • Introduced a novel lens geometry design that optimizes the trade-off between the number of supported viewpoints and the prominence of the lenses on the geometric surface.
  • Achieved the ability to print lenticular lenses on multi-curved surfaces, overcoming the 2D limitations of traditional technologies.
  • Delivered an integrated workflow for design, simulation, and manufacturing.

• Implementation Steps and Key Techniques:

  1. Design Tool:
     • Implemented as a Rhino3D plugin to define viewpoints (via virtual cameras) and assign texture patterns.
     • The tool supports real-time ray tracing to preview the object's appearance.
  2. Lens Generation and Distribution:
     • Used a hexagonal close-packing algorithm to distribute lenses, ensuring no overlap between lenses.
     • Defined UV mapping based on the surface to evenly distribute color patterns at the base of each lens.
  3. Manufacturing and Post-Processing:
     • Used a multi-material 3D printer (Stratasys J55) to print lenses and color patterns in a single process.
     • Applied post-processing (e.g., lacquer spraying) to enhance optical performance.

Research Outcomes

• Specific Results:

  • Developed a complete workflow from design to manufacturing, enabling viewpoint-dependent appearance changes on 3D curved objects.
  • Created a lens geometry configuration supporting up to 19 different viewpoints under simulated conditions.

• Advantages Over Existing Solutions:

  • Enabled the fabrication of lenticular lenses on complex double-curved surfaces.
  • Integrated lens manufacturing and color pattern printing in 3D printing, eliminating the need for manual assembly.

• Experiments and Evaluation Results:

  • Lens Quality Experiments:
    • Among lenses of different diameters (2mm–5mm), 3mm lenses provided a good balance between pattern fidelity and optical quality.
    • Printing orientation significantly affected quality, with upright printing yielding the best results.
  • Pattern Resolution:
    • The minimum supported pattern resolution was 600 microns, suitable for lenses with diameters of 3mm or larger.
  • Physical experiments validated the optical performance, though manufacturing errors limited the maximum number of supported viewpoints (optimal real-world implementation achieved 14 viewpoints).

• Application Scenarios:

  • Used in sports equipment to guide proper posture (e.g., visualizing the correct position of a dumbbell).
  • Added dynamic effects to product designs (e.g., headphone cases displaying different colors depending on the angle).
  • Provided personalized messages for individual users (e.g., custom patterns on shoe surfaces visible only to the wearer).

• Limitations and Future Directions:

  • Lens Impact on Geometry and Tactile Feel: Further work is needed to minimize the impact of lenses on object shape.
  • UV Mapping Issues: Improvements are required to support non-uniform UV mapping.
  • User Interface Improvements: Provide warnings for problematic viewpoint settings.
  • Support for More Complex Lens Types: Future work could include support for lenses of varying sizes or types (e.g., cylindrical lenses).