The document describes 3DRSim, a 3D reconstruction simulator that uses a single image to generate 3D reconstructions of complex objects. It explores using multiple projectors and cameras with algorithms that could be applied to real world scenarios. The demo shows the simulator in action. Challenges include coming up with a pattern and algorithm to get correspondence from one image. The approach detects edges between images, corresponds each edge, and performs ray intersections. Future work includes allowing different camera configurations and more robust methods.

1. 3DRSim
3D Reconstruction Simulator
By Tharindu Mathew

2. Motivation
● Explore ideas to generate 3D
reconstructions of complex objects with a
single image
● Simulation allows us to experiment with a
large number of projectors and cameras
● Algorithms will be applicable in the real world

3. 3D Reconstruction

4. Demo
● Let’s see it...

5. Challenges
● Coming up with a pattern and related
algorithm that will allow us to get a
correspondence with one image

6. Related Work
Rapid Shape Acquisition Using Color Structured Light and Multi-pass Dynamic Programming - Zhang et al.
(2002)

7. Pattern based on De Bruijn sequence
● B(k, n) => A k size alphabet where every local n sequence is
unique
● A Debruijn sequence of an alphabet of size 5, i.e. {a, b, c, d, e},
where any sequence of 3 is unique.
● Assign a color for each letter, ex: a = 101 (RGB), and pick an
initial color
● Generate colors by following: Ci+1 = Ci ⊕ Di

8. Approach
For each horizontal row,
1. detect edges
2. correspond each edge between
two images
3. for each corresponded edge, do
ray intersection

9. Results

10. Future Work
● Use homography to and allow for different
camera configurations
● Experiment with more robust methods

11. Learnings
● Render to texture, Projective Texture
Mapping, Coordinate multiple shaders/
viewports
● 3D reconstruction

12. Acknowledgements
● Prof. Daniel for many of the concepts and related math
● Many openGL tutorials
● Debruijn sequence generator - Used from here -
http://stackoverflow.com/questions/4008603/how-to-
compute-de-bruijn-sequences-for-non-power-of-two-sized-
alphabets
● A wrapper class for loading bitmaps based on this tutorial -
http://www.tomdalling.com/blog/modern-opengl/02-textures/

13. Questions?