Ghost VFX artists in Copenhagen proudly provided visual effects on the Netflix film, including the creation of the troll.

December 14, 2022


When an explosion in the Norwegian mountains awakens an ancient troll, officials appoint a fearless paleontologist to stop it from wreaking deadly havoc.


Ghost VFX artists in Copenhagen worked closely with director Roar Uthaug, VFX Supervisor Esben Syberg and VFX Producer Mikael Windelin to create visual effects for key sequences in the film and were responsible for designing and building the troll asset that was used by all VFX vendors working on the show.

“The creation of the troll included everything from sculpting the base model, his facial expressions, and all surface details, to developing simulation workflows, building the rig and underlying muscle structure, as well as texturing and shading the asset. It all had to be done to a level that would hold up in extreme close ups. Huge parts of the troll’s surface were covered with vegetation and his skin had partly turned into chunks of rocks that all needed to move independently from each other. This resulted in an extremely complex model that still needed to work across all studios even though they didn’t necessarily use the same tools and software packages for shot production.” – VFX Supervisor Claus Kogsboell

Led by VFX Supervisor Claus Kogsboell, Ghost VFX artists in Copenhagen got involved early in pre-production on the film, working from Uthaug’s direction and the visuals from his concept artist. A concept artbook was made for the troll asset exploring the overall look as well as expressions and surface details. From there, Ghost VFX continued exploring ideas through references and concept sculpts before arriving at the final design and production ready asset. In addition to building the hero creature for the movie, Ghost VFX also developed other assets for shot production including helicopters, vehicles and set pieces that the troll had to interact with and destroy along the way. Ghost VFX produced two sequences for the movie which were centered around the troll. The first sequence is where the troll reveals himself for the first time in the film. This sequence required rocks, soil and vegetation to fall off his body– elements that had been growing on him and camouflaging him while sleeping in the mountains and inside caves for a thousand years. The massive weight of his body also meant that Ghost VFX needed to simulate destruction in the terrain as the troll’s feet would break the soil and leave deep footprints as he moved around. The other sequence Ghost VFX handled takes place at a theme park where military helicopters arrive to distract the troll and force him away from this crowded area to avoid havoc and casualties. This sequence included a lot of destruction of helicopters and interaction with the environment as well as some more subtle shots where Ghost VFX explored the emotions of the troll. Previz sequences were delivered as a starting point for shot production informing Ghost VFX about the overall idea for framing and timing. This aided in visualizing ideas at an early stage of production and was a valuable tool for estimating the scope of work and the vision for the sequences Ghost VFX delivered and for the creation of the troll.

We considered bringing the troll to life using motion capture. We even did some tests based on specific shots we knew we would have to do. The challenge with Dovre is that he is a massive creature. He is a staggering 50 meters high beast. With this size you really must consider the speed of his motion. Everything should move quite slowly at this scale due to the force of gravity. If you make him move too fast, it will look and feel unnatural.

"Based on this we found key frame animation to be a much better approach, compared to having an actor try to perform in slow motion or trying to slow down mocap data, which would very easily lead to weird and artificial results. Ghost VFX has a background in key frame-based character animation so this was also a comfortable choice. We created walk cycles that we showed to the director to agree on overall speed and weight of Dovre. We also used these to test the physics of the muscle system that was added to the rig. The walk cycles were also shared with the other vendors to insure consistency between sequences. Another challenge was his facial animation. Dovre is not just a cold-hearted beast. He has feelings and it was extremely important that the audience have sympathy for him at certain points throughout the movie. To achieve the required range of emotion in his performance, we used a FACS based setup that takes into account the natural movement and flow of the facial muscles. This allowed us to create whatever expression the human face is capable of. On top of that we used a facial capture system to drive the performance in some shots, giving us these subtle details and even eye darts that can otherwise take a long time to get right using key frame animation alone. We would of course still be able to animate on top of this to get the desired result. Once the character animation and muscle simulation were in place, we still needed to add the huge amount of vegetation including rocks, roots, grass, and bushes that covered most of his body. All of this added up to thousands of individual pieces that all had to follow his movement in a natural way, and it had to react correctly in relation to gravity and wind. This was all set up by our asset and FX teams and simulated in Houdini.” – VFX Supervisor Claus Kogsboell


Ghost VFX artists were thrilled to create a main character in a film that contains so much complexity in its surface details and simulated dynamics. The asset also had to be shared with other vendors that didn’t necessarily use the same pipeline tools making the task even more challenging. Ghost VFX benefited hugely from being able to communicate directly with the director to achieve his vision for the film. “It was a pleasure working directly with Roar (Uthaug), and it made the process very efficient. He had a clear idea about what he wanted to achieve. But he also gave us the freedom to explore ideas - both when it came to the design of the troll as well as in how to tackle different creative challenges during shot production. We are very proud of the result of this collaboration, and we are looking forward to seeing how the movie will be received by audiences.” – VFX Supervisor Claus Kogsboell