26th février 2024

Creating fast FX in Previs

Framestore Pre-Production Services (FPS) played a significant role in the end to end service that Framestore provided on Loki Season 2. In previs and postvis, FPS planned the complex shots seen in the series, laying a solid foundation for the final effects. The spaghettification phenomenon, first seen in the record store sequence in episode five, presented a number of challenges.

Previs of a cup of coffee turning into strands
A coffee cup turns into strands of coffee

"We had to develop a way of representing the complex FX so they matched the client's vision, and tied in with the Visual Development work, which was being developed in tandem with the previs" explains Visualisation Supervisor Michelle Blok.  "Previs was used as a testing ground to quickly develop and refine story ideas and concepts. Our workflows needed to be agile and flexible to accommodate the continual creative refinement being made by the directors and VFX team.  We needed to find a new way of working that allowed for easy customisation of the spaghettification FX, while still retaining the ability to make changes quickly."

The team initially investigated 3D simulations, but found that they did not provide the flexibility they needed. They pivoted to 2D options, which proved much more successful.  "The result was achieved by utilising After Effects' Red Giant Particular (3D particle system), allowing us to generate 3D particle effects from our 2D renders,  basically turning 2D images into 3D spaghetti!" says Blok. "This gave us complete control as to the colour, size, density, speed and motion of the spaghettification strands, so any changes we were asked to make could be done with the press of a button, avoiding time intensive rendering.  We adjusted the composition of our team to ensure we had the right artists for this new workflow."

This method was used for multiple sequences. The same methodology was used again when the team moved into postvis, by which time the final look for the FX had been refined, and could be seamlessly integrated into the postvis plates.

OB turns into spaghetti strands, leaving just his floating head