Daniel Biurci Scrivener

Publications

Winding Number Features for Vector Sketch Colorization Daniel Scrivener*, Ellis Coldren, Edward Chien Published in Computer Graphics Forum, Vol. 43 Issue 5 Presented at Symposium on Geometry Processing, 2024

SGI Projects

MIT's Summer Geometry Initiative is an intensive introduction to concepts in the field of geometry processing. I had the opportunity to participate as a fellow in 2022, during which time I worked with researchers on three projects.

(Download Slides)

Orienting Point Clouds

Michael Kazhdan - JHU, Tiago De Souza Fernandes, Anna Krokhine, Qi Zhang

Blog Post

• Deals with the classic problem of assigning normals to unoriented points in a set — older 3D scans may lack normal information
• Two-phase approach
  • Local phase: points are clustered according to their k-nearest neighbors and oriented via fitting to an implicit surface representation
  • Global phase: assign signs to each clusters in a greedy fashion
    • Try all 2^c combinations of clusters and see which one minimizes an alignment energy
    • Merge one level up, then repeat until convergence
• Alignment energy of neighboring points: based on the average directional similarity when projected onto the other point's corresponding implicit surface

• We turn this into an energy based on signed clusters as follows:

• Development of new implicit surface representations
• Parabolic Fit (dual-axis parabola)

• "Associative" Fit (hybrid approach that compares two surface types, e.g. plane & unconstrained quadratic)

• Wedge Fit (preserves detail at sharp corners)

Text-Guided Shape Assembly

Matheus Gadelha - Adobe Research, Tiago De Souza Fernandes, Bryan Dumond, Vivien van Veldhuizen

Blog Post

I❤️LA: Compilable Markdown for Linear Algebra

Yong Li - George Mason U., Yotam Gingold - George Mason U., Alec Jacobson - U. of Toronto, Bryan Dumond, Dimitry Kachkovski, Hannah Kaufman, Alejandro Pereira

OpenGL Widgets

Completed for CS 480, Computer Graphics at BU

Lighting Shader Implements the Phong illumination model with support for diffuse, specular, and ambient light Reflectance properties defined per-surface Radial attenutation of light intensity Optional angular attenutation of light source (spotlight) Optional simulation of "infinite" light source (sun) Manual construction of geometric primitives (torus, sphere, cube, cylinder) with indexed vertex buffers

"Vivarium" Simulation Animated models: hierarchical linkages with poseable joints Orientation of creatures in facing direction with quaternions Spherical collision detection between objects Modelling of "hunting" behavior using Gaussian potentials

Daniel Scrivener, 2024