1. Surface Reconstruction And Primitives Extraction The Problem Research Directions Possible Solutions Five minute Summary

2. What am I working on ? My first work consists in checking most of known reconstruction methods. It is a huge topic in computer graphics and I have read numerous papers… Here’s a short presentation of problems I have seen and a part of the main works I plan to do.

3. How can we reconstruct a mesh to represent a surface by knowing only a cloud points and few properties? What properties should the reconstructed surface have? Reconstructed surfaceSmoothed range image Example : range image from IRIS 3D scan archive PROBLEM

4. Range Images Produce Structured Mesh So, a first mesh is easily created by mapping a regular grid on the cloud points Range Images already contain point neighborhood information

5. What about non ordered cloud points? It’s an other part of the problem : instead of the precedent example the points are not ordered. So what kind of techniques can we use to construct resulting surface? Example with Mannequin head reconstructed cloud point (IRIS LAB Database) Reconstructed MeshCloud Points Result

6. Example of Existing Primitive Extraction Methods Automatic Reconstruction of Surfaces and Scalar Fields from 3D Scans Chandrajit L. Bajaj Fausto Bernardin Guoliang Xu Department of Computer Sciences Purdue University SURFACE PATCHES J. C. Carr R. K. Beatson J. B. Cherrie T. J. Mitchell W. R. Fright B. C. McCallum T. R. Evans University of Canterbury SKELETON EXTRACTION SUPERQUADRICS Images from: Yan Zhang’s superquadrics reconstruction, IRIS LABIRIS LAB University of Tennessee

7. Research Directions Many work directions : Primitives extraction / features detection to reduce the number of parameters (patches, subdivisions surfaces…) Hierarchical reconstruction to be able to represent the surface at many resolution levels Reconstruction itself : properties, quality, speed… Images from Michael Roy’s works on multiresolution meshes, IRIS LABIRIS LAB University of Tennessee

8. Possible Solutions (?) This part is subject to evolve all the time. But we already have many ideas : Find “good” curves on cloud points to minimize curvature energy to create an initial parameterization for rough patches Define for each coarse patch a rough surface approximating the mesh Extract higher frequencies (details) from the differences between the real mesh and the approximating patch1 Parameterization among iso-value curves