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DNEG Delivers Mushrooming VFX on ‘Sonic the Hedgehog 2’

The studio handles 185 shots on Jeff Fowler’s ‘Sonic the Hedgehog’ sequel, including the environmental build of the Mushroom Planet, the interior of a giant mech robot, and a massive explosive shockwave.

At the end of Paramount Pictures’ 2020 hit, Sonic the Hedgehog, Dr. Robotnik (Jim Carrey) was banished to the Mushroom Planet, setting the stage for a sequel that revisits the egomaniacal scientist and his cosmic predicament. Hitting theaters this past April 8, that sequel, Sonic the Hedgehog 2, in addition to Carrey, stars returning cast members Ben Schwartz, James Marsden, and Tika Sumpter; also returning are filmmaker Jeff Fowler, and visual effects supervisor Ged Wright (22 July).  A late addition to the visual effects team was DNEG, which handled four sequences encompassing 185 shots that included the environmental build of the Mushroom Planet, the construction of the interior of a giant mech robot, and the execution of a massive shockwave.

DNEG created the environment for the Mushroom Planet while MPC integrated the characters.  “Based on the concept art provided by the client, we built that environment and put it in layout, which was shared with MPC so they could figure out where the camera needed to be,” states DNEG VFX supervisor Kunal Ghosh Dastider.  “There was a back and forth with MPC.” 

A partial set with bluescreen was built on a soundstage, which was LiDAR scanned.  “The grass and first row of mushrooms were real,” reveals Ghosh Dastider. “We would extend from there.”  Unlike the usual mandate of producing photorealistic CG that fits into the real world, on the Mushroom Planet, there was more room for creative freedom.  “No one has seen a Mushroom Planet before,” remarks the VFX supervisor.  “It was trippy and crazy.  It was creative work that was fun to explore.”  One constraint was that Fowler did not want the planet to feel overfilled with mushrooms.  “We did concepts so it wouldn’t be just a farm field of mushrooms everywhere,” Ghosh Dastider notes. “Things were broken up with rocks or mountains where mushrooms would grow out of to give it scale and depth.  There was a hand-placed pass for the bigger mushrooms. Then we had a procedural way to scatter smaller ones to fill it up.”


Being able to convey scale was a major challenge in a world populated by 30-foot mushrooms.  “As human beings we see little mushrooms, so it was difficult to given them depth,” Ghosh Dastider says. “If a mushroom was really 30 foot tall, the problem is the texture detail and having something that you can relate to such as moss or soil.  You add scratches or colorization until it feels right.”  Atmospherics were also incorporated into the imagery.  “We tried to add additional elements like mist and wind to have the feeling of things moving in background,” he continues, sharing that the digital matte paintings in the background were based on skies from the real world. “It was a dawn type of mood that was given, and we were also bounded by the studio lighting.  We added atmospherics in the lighting.” Contrast was achieved through the compositing, where smaller mushrooms were made darker so everything higher up catches more light to help with the scale. 

Found throughout the landscape are Rube Goldberg traps that Robotnik has constructed to thwart adversarial visitors to the planet.  Ghosh Dastider explains, “There was a catapult mushroom, and another was this mushroom slab that rotated, threw all of these mushrooms down, and this big stem would slide down and hit all of the evil guys.”  The crazy contraptions still had to honor physics, with Zach Umperovitch brought onto the project as a Rube Goldberg consultant.  “We had the creative freedom to come up with crazy ideas but it was still grounded in terms of real-world physics so it doesn’t feel silly,” Ghosh Dastider says. “We weren’t sure how to approach the catapult mushroom. How do you cut a mushroom to build a catapult?  Would you slice it up?  Would you take a mushroom with a long or short stem?  Then we tried things out and eventually it feels right.”   

A massive shockwave and aftershock had to be created.  “That was where we could give mushrooms motion and bend them because we wanted to show this enormous power,” states Ghosh Dastider.  “There is this old school reference from nuclear tests that the U.S. did a long time ago.  There is slow motion where dust kicks up or you see the trees are bending. That was good reference for the mushrooms as they were the same size as the trees.”  The physically based simulations employed had to be art directed.  Though the software does the physics, the VFX supervisor reminds us “we’re still doing movie magic - we’re bending reality.” He adds, “Especially for the top-down-view we had, it needed to work for that dramatic camera angle.  We did some tests where the mushrooms were bending. [But, it was noted,] ‘This would be realistic but we barely read something because a 30-foot mushroom hardly moves.’  Visually you had to see the shockwaves going out and that the mushrooms are bending.” 

In order to read the shockwave properly, the shot was extended.  “We did a layout pass with a simple sphere to time it out,” Ghosh Dastider describes.  “The first shockwave kicked up everything in terms of dust and there was the second one when the electricity bursts out.  We did tests to try various things out.  There were a lot of different layers that could be played with in compositing.  A volume layer was added to give it a dome type of feel.  The electricity was so bright that the challenge was to be able to read that dome and for it not to feel flat.  We had some little electricity stuff happening for the shot where we see it from the galaxy.  We added electricity that would crawl on the ground, and in the dome itself there was some electricity stuff that would light up that volume in order to give it more dimension.  We had to keep it in that blue whiteish world.”

As Robotnik and Sonic clash, the doctor chases the hedgehog inside a giant mech robot.  “The brain of the robot is a huge dome,” notes Ghosh Dastider.  “Most of that environment was dark until the emerald electricity comes on and lights it up.  The tricky part was to get the detail and scale that communicates this is huge.”  He adds that LED screens were placed around a practically built dome that projected electricity lighting elements and “gave the timing of the electricity and we got all of the interactive lighting on Robotnik.”  Additional concept art was done by DNEG for the interior of the dome.  Ghosh Dastider reveals, “We had painted and brushed metal because since the dome is a sphere, it is hard for you to understand where you are in the room.  We added displacement elements so when the lightning would light it up, you’d see that.  Screws and bolts were added just to give that extra detail.” 

After completing Sonic the Hedgehog 2, Ghosh Dastider laughs at the suggestion that he has become an expert on mushrooms.  “If I see mushrooms, I’m always analyzing them!”  Noting that his team’s biggest creative challenge was creating the Mushroom Planet, the VFX supervisor concludes, “It’s a good entrance into the movie. It was fun creating something that nobody has seen before.”

Trevor Hogg's picture

Trevor Hogg is a freelance video editor and writer best known for composing in-depth filmmaker and movie profiles for VFX Voice, Animation Magazine, and British Cinematographer.