The FX magic of ‘Onward’

FX magic

2D, 3D and confidence arcs

Dan Scanlon’s Onward has a whole bunch of fantastical characters, and one of them could be considered to be the ‘magic’ of the Pixar film itself.

To portray the magical effects seen in the film – in a world that has extensibly forgotten about magic – Pixar looked to go for a more stylistic approach than perhaps it had done so previously. This meant hand-drawing FX elements for the magic before bringing it into 3D for final animation, lighting and rendering.

At SIGGRAPH Asia in Brisbane last year, effects TD Cody Harrington broke down how that all worked, including the implementation of confidence arcs, the making of the ‘Conjuring Dad’ sequence and the relationship between 2D and Houdini-generated FX in the film.

1. Story set-up

The story determined that Ian (the character voiced by Tom Holland) is a fledgling magician, and so often fails at first to conjure the right spells. But the idea was that he slowly gets better at magic. Pixar charted these ‘confidence arcs’ and then would increase the intensity of magic and the confidence into each new spell.

Ian's confidence arc
Ian’s confidence arc.
power of the spell
How the confidence arc impacted on the power of the spell.
Spell intensity levels
Spell intensity levels.

2. An abstract look

Since the world of the film does not seem to have magic anymore, the decision was made to render magical effects in a more abstract way. Pixar noticed that in many feature films – which they looked to for reference – that the magical effects tended to be ‘alien-looking’. That’s not what they wanted to feature; instead it was about fitting the magic look into a more ‘realistic’ world.

Conjuring Dad' sequence by Le Tang
Storyboard frame for the ‘Conjuring Dad’ sequence by Le Tang.
Concept art for the magical beam
Concept art for the magical beam.

3. 2D to 3D

They started with 2D timing tests that were hand-drawn pieces. Concept paintings came from the art department. The film’s effects supervisor, Vincent Serritella, a fine artist himself, would then actually craft 2D FX ‘cell drawings’ in that style, and then Pixar’s FX team built a pipeline, using Houdini, that allowed these 2D creations to be projected into 3D for effects animation.

Effects supervisor Vincent Serritella
Effects supervisor Vincent Serritella works in Houdini on ‘Onward’. (Photo by Deborah Coleman / Pixar)

Serritella also did draw-overs over a series of frames. Remember, the idea was to retain a sense of stylization to the magic and keep a ‘drawn’ look. The animation was put onto cards and used as a light source, which helped integrate the FX into the final scene.

Ultimately, this process tied in with all the other work the studio was handling in its Presto animation toolset, its renderer RenderMan, and utilizing the latest developments in USD.

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