X-Particles Challenge 2019 - Snow Crevice

XPC2019-OlivierCefai

Creating a realistic snow is both a simulation and a shader challenge!

Creating a realistic snow is both a simulation and a shader challenge!

Calculations where becoming insane. I had to rework the scene and optimize it as much as possible in order to meet the Challenge deadline!

Calculations where becoming insane. I had to rework the scene and optimize it as much as possible in order to meet the Challenge deadline!

I sculpted some orb-style details on the X in Zbrush then exported the displacement map into a Cycles4D shader. Unfortunately it is not so visible on the final version because I had to change my snow falling simulation to meet the deadline...

I sculpted some orb-style details on the X in Zbrush then exported the displacement map into a Cycles4D shader. Unfortunately it is not so visible on the final version because I had to change my snow falling simulation to meet the deadline...

Editing in Resolve. I layered 4 different sound effects to give depth to the shot.

Editing in Resolve. I layered 4 different sound effects to give depth to the shot.

Compositing using cryptomattes from Cycles4D

Compositing using cryptomattes from Cycles4D

Color grading in 32 bits linear to fine tune superwhites

Color grading in 32 bits linear to fine tune superwhites

In December 2019, I had the privilege to be one of the winners (4th position) of the X-Particles Challenge 2019 with this work.

The idea is inspired by a Houdini course by Steven Knipping, but I created this using X-Particles instead, and added some layers of complexity by mixing volumetric, grains and fluids workflows. Indeed, this simulation combines 4+ layers of snow (all custom-designed shaders). I also came up with a neat compositing trick to create believable avalanche-like powder snow: layering multiple simulations at different FPS rates.

Created on:
iMac Pro 3Ghz 10 Cores with 128Gb Ram and external GTX 1080Ti (High Sierra OSX)
Final simulation calculation: 5 hours (after serious optimization and tricks)
Rendering time: approx 140 hours

X-particles dynamics with grain simulation, xpFluidFX + explosiaFX + xpConstraints + multiple C4D volumes and fields.
Displacement maps sculpted in Zbrush for Cycles4D.

Date
December 21, 2019