Early artwork for Guardians of the Galaxy revealed

Marvel's Guardians of the Galaxy has proven to be this summer's big movie success. An epic, sweeping galactic adventure, ensuring the major scenes stayed on track and true to director James Gunn's vision proved a challenge for previs studio Proof.

Proof worked closely with Gunn for the past year-and-a-half to previs several of the biggest action sequences. Ron Frankel, Proof's founder and creative director explains: "Guardians of the Galaxy presented us with numerous big action sequences that have really never been done before. Full CG, high-adreneline battle sequences that required a lot of choreography."

It was essential that viewers don't get lost in the action sequences and CG-heavy scenes, and every scene was developed with the audience's view in mind.

Another big challenge for Proof and James Gunn was bringing the two CG leads to life, Groot the talking tree and Rocket Racoon. The audience needed to forget these were CG or even unusual and embrace them on level terms with the actors.

"It was very important to James that the audience forget that these two characters were CG, and, instead, accepts them as real characters - characters that actually exist in the world of the film - because they really are the heart of the movie," says Earl Hibbert, Proof's previs supervisor.

From a technical point of view it was important that the previs scenes worked together with the CG environments, green screen scenes and real sets. Working closely with the film's production designer Charlie Wood and visual effects supevisor Stephane Ceretti ensured the previs sets matched the dimensions of the actual build.

"In this manner," says Hibbert, "the action we designed during previs could be captured on set, while still giving James [Gunn] the flexibility to improvise new shots."

A key stage for the team was switch from previs to postvis work, again led by Hibbert. The job at hand was to create a cut of the film for James Gunn to work with that included all the CG scenes, set extensions and CG characters. In total there were 1900 VFX shots to postvis.

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