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2+2D Texture for Full Positive Parallax Effect

Alexandre Yip Gonçalves Dias, Marcelo Knörich Zuffo

TL;DR

This work tackles the challenge of rendering large-disparity parallax by introducing a 4D Light Field–based texture, defined as $T(u,v,s,t)$, that encodes both surface position and light directions within a spherical model to enable positive parallax. A render algorithm performs bidirectional interpolation across spatial and angular dimensions, mapping rays to a local frame at each surface point and sampling 16 angular-spatial texture values to produce final pixels. The approach is demonstrated through two test scenes: an aliasing-focused single-object scene and a composed scene approximated by a large sphere, with ray-traced textures and 7× supersampling to mitigate aliasing, achieving real-time performance (approximately $180$ fps) in Unity on a high-end GPU. Results indicate the method can reproduce parallax, occlusion, and related effects under the proposed constraints, suggesting potential for immersive spherical displays and multi-viewer extensions, albeit at the cost of substantial storage and with restrictions on observer placement.

Abstract

The representation of parallax on virtual environment is still a problem to be studied. Common algorithms, such as Bump Mapping, Parallax Mapping and Displacement Mapping, treats this problem for small disparity between a real object and a simplified model. This work will introduce a new texture structure and one possible render algorithm able to display parallax for large disparities, it is an approach based on the four-dimensional representation of the Light Field and was thought to positive parallax and to display the surfaces on the inside of our simplified model. These conditions are imposed to allow the free movement of an observer, if its movement is restrict, these conditions may be loosen. It is a high storage low process approach possible to be used in real time systems. As an example we will develop a scene with several objects and simplified them by a unique sphere that encloses them all, our system was able to run this scene with about 180fps.

2+2D Texture for Full Positive Parallax Effect

TL;DR

This work tackles the challenge of rendering large-disparity parallax by introducing a 4D Light Field–based texture, defined as , that encodes both surface position and light directions within a spherical model to enable positive parallax. A render algorithm performs bidirectional interpolation across spatial and angular dimensions, mapping rays to a local frame at each surface point and sampling 16 angular-spatial texture values to produce final pixels. The approach is demonstrated through two test scenes: an aliasing-focused single-object scene and a composed scene approximated by a large sphere, with ray-traced textures and 7× supersampling to mitigate aliasing, achieving real-time performance (approximately fps) in Unity on a high-end GPU. Results indicate the method can reproduce parallax, occlusion, and related effects under the proposed constraints, suggesting potential for immersive spherical displays and multi-viewer extensions, albeit at the cost of substantial storage and with restrictions on observer placement.

Abstract

The representation of parallax on virtual environment is still a problem to be studied. Common algorithms, such as Bump Mapping, Parallax Mapping and Displacement Mapping, treats this problem for small disparity between a real object and a simplified model. This work will introduce a new texture structure and one possible render algorithm able to display parallax for large disparities, it is an approach based on the four-dimensional representation of the Light Field and was thought to positive parallax and to display the surfaces on the inside of our simplified model. These conditions are imposed to allow the free movement of an observer, if its movement is restrict, these conditions may be loosen. It is a high storage low process approach possible to be used in real time systems. As an example we will develop a scene with several objects and simplified them by a unique sphere that encloses them all, our system was able to run this scene with about 180fps.
Paper Structure (10 sections, 5 equations, 4 figures, 1 table)

This paper contains 10 sections, 5 equations, 4 figures, 1 table.

Table of Contents

  1. Introduction
  2. 2+2D Texture Theory
  3. Render Process
  4. Texture Restrictions
  5. Test Scene
  6. Aliasing Scene
  7. Composed Scene
  8. Results
  9. Conclusion
  10. Acknowledgment

Figures (4)

  • Figure 4: 2D Illustration showing the effect of differenties observer's placements.
  • Figure 5: Images showing the different aliasing effect produced by moving an object away from the model surface.
  • Figure 6: Comparison between textures without(\ref{['fig:aliasTex']}) and with(\ref{['fig:antiAliasTex']}) 7x supersample anti-aliasing method
  • Figure 7: Comparative between the models' renderization and the effect produced by our texture under several configuration of resolutions over several point of view.