New website:

Please go to my new website:
(See the full publication list here)

I have two new papers to appear:

Connectivity Editing for Quad-Dominant Meshes, Chi-Han Peng and Peter Wonka, Eurographics Symposium on Geometry Processing (SGP) 2013

Paper (author's version) / Additional materials / Video (YouTube)

We propose a connectivity editing framework for quad-dominant meshes. In our framework the user can edit the mesh connectivity to control the location, type, and number of irregular vertices (with more or less than four neighbors) and irregular faces (non-quads). We provide a theoretical analysis of the problem, discuss what edits are possible and impossible, and describe how to implement an editing framework that realizes all possible editing operations. In the results we show example edits and illustrate advantages and disadvantages of different strategies for quad-dominant mesh design.

Exploring Quadrangulations, Chi-Han Peng, Michael Barton, Caigui Jiang, and Peter Wonka, ACM Transactions on Graphics (TOG), conditionally accepted with minor revisions.

We present a framework for exploring topologically unique quadrangulations of an input shape. First, the input shape is segmented into surface patches. Second, different topologies can be enumerated and explored for each patch. This is realized by an efficient subdivision-based quadrangulation algorithm that can exhaustively enumerate all mesh topologies within a patch. To help users navigate in the potentially huge collection of variations, we propose tools to preview and arrange the results. Furthermore, the requirement that all patches need to be jointly quadrangulatable is formulated as a linear integer program. Finally, we show applications to shape space exploration, remeshing, and design to underline the importance of topology exploration.
I will work for Adobe ATL at San Jose as a research intern during the summer.

KAUST, Saudi Arabia

I visited GMSV at King Abdullah University of Science and Technology (KAUST), Saudi Arabia during the winter break to join my adviser for the Siggraph deadline.

User-Assisted Mesh Simplification

Download Page:

Presentation Slides( for my Master Defense):


A novel approach for user to precisely increase the vertex resolution of desired regions on the simplified mesh, while preserving the global vertex count:

Algorithm Summary:
  1. Generate a Progressive Mesh (PM) for the model: a continuous sequence of edge collages that will gradually reduce the model to only 1 vertices.
  2. In the PM, locate all edge collapse pairs on the target region to be refined, denoted as eg.
  3. Specify the desired global vertex count after simplification, denoted as g.
  4. Specify the desired vertex count for the target region after simplification, denoted as x.
  5. Identify ecX, which is the marginal edge collapse that will immediately reduce the target region to x vertices.
  6. Exchange the order of ecX with the (g+1)-th edge collapse of PM, making it the new (g+1)-th edge collapse of PM.
  7. Linearly reallocate the execution order of all other edge collapses of eg to preserve the original order of eg.
  8. As a result, the target region will have x vertices after simplification.

User can precisely allocate more vertices to regions of interest on a simplified mesh.

This paper is primarily based on my Master thesis paper. Mr. Ho, a senior PhD. student of my lab, helped re-organized and submitting this paper.