Juan Raúl Padrón Griffe

Epale! I am a Marie Sklodowska-Curie fellow of the EU Project PRIME and a PhD candidate at the Graphics and Imaging Lab (Universidad de Zaragoza). My PhD thesis under the supervision of Prof. Adolfo Muñoz and Adrian Jarabo focuses on developing theory and methods for accurate and efficient rendering of complex volumetric appearances. Previously, I obtained my Bachelor degree in Computer Science (2015) at the Central University of Venezuela. Later, I received my Master degree in Informatics (2020) at the Technical University of Munich. During my Master studies I focused mostly on the Computer Graphics and Vision subjects, where I was fortunate enough to be advised by Prof. Matthias Niessner and Dr. Justus Thies at the Visual Computing lab to conduct my research on 3D Scanning and Neural Rendering. I am currently looking for a postdoctoral position.

I am a computer scientist enthusiastic about the intersection of realistic image synthesis, graphics-based vision and machine learning for the digital acquisition, representation and understanding of the visual world. I am currently interested in pushing the state of the art on physically-based rendering of complex multi-scale materials like biological tissues. In my research, I rely on powerful tools like Monte Carlo simulation and gradient-based optimization. In the long term, I believe the combination of powerful forward models (simulation algorithms) and inverse models (gradient-based models) could be impactful in other interesting domains too like computational biology.

Projects

Foundation Cosmetics Rendering (EGSR 2024)

2024, Jul 01    

We started this project two years ago lead by Dario Lanza when we visit Jeppe Frisvad as part of our first secondment. The project was a collaboration between three research groups: Graphics and Imaging Lab, DTU Visual Computing Section and Media Design and Image Reproduction. Our work is going to be presented by Dario Lanza at the Eurographics Symposium on Rendering (EGSR 2024, South Kensington, London) under the title “Practical Appearance Model for Foundation Cosmetics”. We represent each individual layer as a stochastic participating medium with two types of scatterers inspired by the microscopic constituents inside foundation cosmetics that mimic the most prominent visual features of these cosmetics: diffuse scatterers responsible for the matte appearance and specular platetets responsible for the glossy looks. The implementation consists of a multi-layered material implemented inside the physically-based renderer PBRT version 4 using the Position-Free Monte Carlo formulation. The specular platelets are modelled using the SGGX microflake phase function, while the diffuse particles are modelled with a two-lobe Henyey-Greenstein phase functions. If you would like to know more about this project, then please visit the official project website Practical Appearance Model for Foundation Cosmetics. Below you can find a practical example where we add two cosmetics layers on top of a white female character’s skin (left, bottom layer): a matte finish (center, middle layer) and a red shinier layer (right, top layer).

Rendering of foundation cosmetics

Team Members: Dario Lanza, Juan Raul Padron Griffe, Alina Pranovich

Github repository (Coming soon)

Carlos Aliaga and his colleagues recently release the source code of BioSkin. An interesting technique that can predict the biophysical skin properties from RGB reflectance and we think could potentially be combined with our appearance model in order to render the cosmetic foundations on different skin types.

Twitter
# Appearance Modeling # Rendering