DNEG Brings Mushroom VFX in ‘Sonic the Hedgehog 2’

At the end of Paramount Pictures’ 2020 hit, Sonic the Hedgehog, Dr. Robotnik (Jim Carrey) is banished to Mushroom Planet, setting the stage for a sequel that revisits the egomaniac scientist and his cosmic predicament. Hitting theaters on April 8th, the sequel, Sonic the Hedgehog 2, in addition to Carrey, stars Ben Schwartz, James Marsden, and Tika Sumpter; Also returning is filmmaker Jeff Fowler, and visual effects supervisor Ged Wright (July 22). The final addition to the visual effects team was DNEG, which handled four sequences spanning 185 shots that included the construction of the Mushroom Planet environment, the interior construction of a giant mech robot, and the execution of a massive shockwave.

DNEG creates the environment for Mushroom Planet while MPC integrates the characters. “Based on concept art provided by the client, we build that environment and put it in a layout, which is shared with the MPC so they can know where the camera should be placed,” said DNEG VFX supervisor Kunal Ghosh Dastider. “There is a back and forth with MPC.”

A partial set with a blue screen is built on the soundstage, which is scanned by LiDAR. “The grass and the first row of mushrooms are real,” says Ghosh Dastider. “We will extend from there.” Unlike the usual mandate to produce photorealistic CG that is true to the real world, at Mushroom Planet, there’s more room for creative freedom. “No one has seen Mushroom Planet before,” said the VFX supervisor. “It was trippy and crazy. It’s a creative piece that’s fun to explore.” One of the obstacles is that Fowler doesn’t want the planet to feel like it’s infested with mold. “We did the concept so it’s not just mushroom fields everywhere,” notes Ghosh Dastider. “Things are broken down with rocks or mountains where mold will grow to give it scale and depth. There is a pass for larger mushrooms. Then we have a procedural way of deploying smaller ones to fill them.”

Being able to convey scale is a huge challenge in a world inhabited by 30-foot-tall mushrooms. “As humans, we see tiny mushrooms, so it’s hard to give them depth,” said Ghosh Dastider. “If the mushrooms are really 30 feet tall, the problem is in the detail of the texture and having something you can relate to like moss or soil. You add strokes or coloring until it feels right.” Atmosphere is also incorporated into the image. “We tried to add additional elements like fog and wind to feel something moving in the background,” he continued, sharing that the digital matte painting in the background was based on the sky from the real world. “That’s the kind of mood dawn gives, and we’re also limited by the studio lighting. We added atmosphere to the lighting.” Contrast is achieved through compositing, where the smaller mushrooms are made darker so that anything taller catches more light to help the scales.

Found throughout the landscape are Rude Goldberg traps that Robotnik has created to thwart hostile visitors to the planet. Ghosh Dastider explains, “There’s a slingshot mushroom, and the other is a mushroom plate that spins around, throws all these mushrooms down, and this big stick will slide down and hit all the bad guys.” Crazy tools still have to respect physics, with Zach Umperovitch brought into the project as a consultant to Rube Goldberg. “We have the creative freedom to come up with crazy ideas, but it’s still based on real-world physics so it doesn’t feel silly,” says Ghosh Dastider. “We’re not sure how to approach the catapult mushroom. How to cut mushrooms to make a slingshot? Would you like to slice it? Do you pick mushrooms with long or short stems? Then we tried different things and it finally felt right.”

Huge shock waves and aftershocks had to be created. “That’s where we can give the mushroom movement and bend it because we want to show this incredible power,” said Ghosh Dastider. “There are old-school references to the nuclear tests that the US conducted a long time ago. There is a slow motion where the dust appears or you see the trees bending over. It’s a good reference for mushrooms because they are the same size as the tree.” The physical-based simulations used should be art-directed. Even though the software does the physics, the VFX supervisor reminds us “we still do film magic – we bend reality.” He added, “Especially for the top-down look we had, it needed to work for those dramatic camera angles. We did some tests where the mushrooms bend. [But, it was noted,] ‘It would be realistic but we barely read anything because the 30ft mushroom was barely moving.’ Visually you should see the shock wave going out and the mushroom bending.”

To read the shockwave correctly, the shot is extended. “We did a layout pass with a simple ball to set the time,” explains Ghosh Dastider. “The first shockwave scorched everything in terms of dust and there was a second when the electricity exploded. We did tests to try different things. There are many different layers to play with in compositing. A volume layer is added to give it a dome-like feel. The electricity was so bright that the challenge was to be able to read the dome and not to feel flat. We had some little electrical stuff going on for the shot where we saw it from the galaxy. We add electricity that will crawl on the ground, and in the dome itself there are some electrical items that will light up the volume to give it more dimension. We have to keep it in that whitish blue world.”

As Robotnik and Sonic clash, the doctor chases the hedgehog inside a giant mech robot. “The robot brain is a huge dome,” notes Ghosh Dastider. “Most of the neighborhood was dark until the emerald electricity came on and lit it. The hard part is getting to the detail and the scale that communicates this is huge.” He added that the LED screens were placed around a practically constructed dome that projected electric lighting elements and “gives electric timing and we get all the interactive lighting at Robotnik.” Additional concept art was done by DNEG for the interior of the dome. Ghosh Dastider revealed, “We’ve painted and brushed the metal because the dome is spherical, it’s hard for you to understand where you are in the room. We added a displacement element so that when the lightning will light it up, you’ll see it. Screws and bolts were added just to provide extra detail.”

After finished Sonic the Hedgehog 2, Ghosh Dastider laughed off the suggestion that he had become a mushroom expert. “When I see mushrooms, I always analyze them!” Noting that his team’s biggest creative challenge was creating Mushroom Planet, the VFX supervisor concluded, “This is a great entry into the film. It’s great fun creating something that no one has seen before.”

Trevor Hogg's photo

Trevor Hogg is a freelance video editor and writer best known for compiling in-depth filmmakers and film profiles for VFX Sound, Animation Magazineand British Cinematographer.


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