by MPC R&D
10 April 2019
Creating realistic skin wrinkles for Dumbo
When MPC Film was entrusted with creating the elephants as CG characters for Disney’s Dumbo, we wanted to ensure they looked as realistic and believable as possible.
Here Chris Mckenna, Head of TechAnim and Lead Software Developer Christoph Genzwürker provide some insight into the creation of a new workflow to deliver realistic wrinkles for the films elephants.
According to Chris Mckenna “It was clear from the client and the VFX Supervisor Patrick Ledda that due to the various ranges of movement, the elephants would need very realistic skin movement and wrinkling if they were to be believable, particularly the ‘criss-cross’ pattern an elephant has”.
There needed to be much finer detail, more than we had done previously if MPC were to get the elephants to blend into the live action seamlessly.
“Previously we would run the skin wrinkles on a typical resolution 3D mesh. However with much less topology to work with this resulted in less detailed wrinkles. The process was also very manual for artists in both out Rigging and Techanim departments, making the whole process very time consuming.
When considering the requirements for Dumbo, MPC knew that they had to look into a different approach.
MPC Film’s R&D Dept. investigated the problem and created a new workflow that could be used across the three main departments involved – Rigging, TechAnim and Lighting and globally because Dumbo was being worked on across multiple MPC sites.
A higher resolution version of the mesh was created by subdividing the original multiple times. Point positions from the higher mesh were then extracted and stored as metadata and used with a custom operator in Katana which would only process at render time. This allowed greater control as to when to use the high quality skin from shot to shot and also allowed the artists to check the looks and behaviour throughout production.
Test of the high quality skin movement on elephant.
According to Lead Software Developer Christoph Genzwürker “Dumbo was produced across multiple global sites making the transfer of heavy files also an issue. To combat this, the new workflow needed to reduce the number of geometry layers transferred between sites. This was done by creating the cache data only on the target site, which reduced the synchronization time between sites dramatically.
The new workflow allowed MPC Film to meet the clients brief and successfully reproduced the detailed and nuanced wrinkles of Dumbo and the other elephants in the movie.
MPC R&D will be hopefully presenting more on this work at this year’s Siggraph in July.