Ola Nilsson

Research

The title of my thesis is “Level-Set Methods & Geodesic Distance Functions” and deals mainly with algorithmic and mathematical aspects of geometric modelling, computational geometry and physically based simulation. For examples see the bunny figures above.
The level-set method is a form of grid-based implicit surface representation with an additional toolbox of mathematics. Look at wikipedia for an introduction, or see this book for a state-of-the-art review of the area.

I like to work with graphics from a scientific and mathematical point of view but I also take an active interest in artistic creation.

Projects and publications

Compression and out-of-core techniques for level sets showing examples of unprecedented size. Applications taking advantage thereof.

• “Out-of-core and Compressed Level Set Methods”, M. Nielsen, O. Nilsson, A. Söderström and K. Museth, ACM Transaction On Graphics, 2007. [PDF]
• “Virtually Infinite Resolution Deformable Surfaces”, M. Nielsen, O. Nilsson, A. Söderström and K. Museth. Proceedings of the SIGGRAPH 2006 Conference on Sketches & Applications. ACM Press. [PDF]

Reconstruction from contours using level sets

• “Surface Reconstruction Via Contour Metamorphosis: An Eularian Approach With Lagrangian Particle Tracking”, O. Nilsson, D. Breen, K. Museth. Proceedings of IEEE Vis 05. [PDF]

Sparse representation of level sets using hierarchical run length encoding of topology

• “Hierarchical RLE level set: A compact and versatile deformable surface representation”, Houston, B, Nielsen, M, Batty, C, Nilsson, O and Museth, K. ACM Transaction On Graphics, Vol. 25, No. 1, pp 1-24, January issue, 2006. [PDF]
• “Gigantic Deformable Surfaces”, Houston, B, Nielsen, M, Batty C, Nilsson, O and Museth, K. (2005). Proceedings of the SIGGRAPH 2005 Conference on Sketches & Applications. ACM Press. [PDF]

Rendering

• “Distributed Ray-Tracing In An Open Source Environment”. (Work In Progress). Johansson, G, Nilsson, O, Söderström, A, and Museth, K. (2006). Proceedings of the SIGRAD 2006 Conference. Linköping University Electronic Press.

Distance transforms

• “Distance maps in an arbitrary metric tensor field, An iterative solver for 2-D charts", Ola Nilsson and Anders Brun. Proc. Swedish Symposium in Image Analysis, 2008.
• “Euclidian Distance Transform Algorithms, A Comparative Study”. Nilsson, O and Söderström, A. Technical report. Linköping University Electronic Press. [link]

Related stuff

File parser for assignment code
Level set raytracing
CEL shading for pbrt

Older
The matrix effect - Image rewriting using random rasters

Updated: Feb 12, 2009