Balancing nostalgia with innovation in S.T.A.L.K.E.R. 2: Heart of Chornobyl
Image courtesy of GSC Game World
About GSC Game World
GSC Game World, a Ukrainian video game developer, was founded in 1995 and is renowned for the S.T.A.L.K.E.R. and Cossacks series. The studio is committed to delivering top-tier gaming experiences and is currently focused on the upcoming release of ‘S.T.A.L.K.E.R. 2: Heart of Chornobyl’.
GSC Game World, a Ukrainian video game developer, was founded in 1995 and is renowned for the S.T.A.L.K.E.R. and Cossacks series. The studio is committed to delivering top-tier gaming experiences and is currently focused on the upcoming release of ‘S.T.A.L.K.E.R. 2: Heart of Chornobyl’.
As many gaming industry veterans know, it’s been over 15 years since the original S.T.A.L.K.E.R. trilogy took the industry by storm. The beloved S.T.A.L.K.E.R: Shadow of Chernobyl, Clear Sky, and Call of Pripyat immersed players in the Zone—a dark, dangerous, and deadly place where players fear not only the radiation, anomalies and menacing creatures, but other S.T.A.L.K.E.R.s who have their own goals and wishes in mind.
Now, with S.T.A.L.K.E.R. 2: Heart of Chornobyl’s long-awaited release nearly upon us, the team at GSC Game World has taken on the task of balancing nostalgia with innovation while retaining the atmospheric storytelling, intense survival mechanics, and detailed world of the original titles.
In S.T.A.L.K.E.R. 2: Heart of Chornobyl, the game’s environments and atmosphere play a central role in the immersive experience as visceral combat keeps players on the edge of their seats and amped-up enemy AI aims to deliver an immersive and lifelike combat experience.
To achieve these elements and all of their goals for the project, GSC Game World switched to Unreal Engine after using in-house engines for the first three titles. To learn more, we caught up with Andrii Levkovskyi, Lead AI Programmer and Maksym Yanchyi, Lead Platform Tools Programmer, to explore the role Nanite, Lumen, World Partition, and other UE5 features played in development.
Now, with S.T.A.L.K.E.R. 2: Heart of Chornobyl’s long-awaited release nearly upon us, the team at GSC Game World has taken on the task of balancing nostalgia with innovation while retaining the atmospheric storytelling, intense survival mechanics, and detailed world of the original titles.
In S.T.A.L.K.E.R. 2: Heart of Chornobyl, the game’s environments and atmosphere play a central role in the immersive experience as visceral combat keeps players on the edge of their seats and amped-up enemy AI aims to deliver an immersive and lifelike combat experience.
To achieve these elements and all of their goals for the project, GSC Game World switched to Unreal Engine after using in-house engines for the first three titles. To learn more, we caught up with Andrii Levkovskyi, Lead AI Programmer and Maksym Yanchyi, Lead Platform Tools Programmer, to explore the role Nanite, Lumen, World Partition, and other UE5 features played in development.
Andrii Levkovskyi, Lead AI Programmer: Our approach balances nostalgia and innovation. For long-time fans, we've kept the core elements that define the S.T.A.L.K.E.R. experience: atmospheric storytelling, intense survival mechanics, and a detailed world. For newcomers, we've introduced modern graphics and an intuitive user interface to make it more accessible. These are just examples of our improvements. We’ve also added several hours of directed cutscenes to enhance the narrative experience. This combination ensures that S.T.A.L.K.E.R. 2 honors its heritage while welcoming a new generation of players.
S.T.A.L.K.E.R. 2: Heart of Chornobyl places players into a non-linear story that unfolds in the setting of post-apocalyptic dark science fiction. What role do the environments and overall atmosphere play in bringing this immersive story to life?
Levkovskyi: Environment and atmosphere play a central role in the immersive experience of S.T.A.L.K.E.R. 2. Our carefully crafted world, inspired by the real-life Chornobyl Exclusion Zone, enhances the narrative with its eerily beautiful landscapes, terrifying anomalies, and dynamic weather. This setting not only drives the story forward, but also creates a sense of constant tension and unpredictability that makes players feel like a real part of this post-apocalyptic world.
S.T.A.L.K.E.R. 2: Heart of Chornobyl places players into a non-linear story that unfolds in the setting of post-apocalyptic dark science fiction. What role do the environments and overall atmosphere play in bringing this immersive story to life?
Levkovskyi: Environment and atmosphere play a central role in the immersive experience of S.T.A.L.K.E.R. 2. Our carefully crafted world, inspired by the real-life Chornobyl Exclusion Zone, enhances the narrative with its eerily beautiful landscapes, terrifying anomalies, and dynamic weather. This setting not only drives the story forward, but also creates a sense of constant tension and unpredictability that makes players feel like a real part of this post-apocalyptic world.
In terms of combat gameplay, how have you managed to retain the feel of the original game while refining the experience for a modern audience?
Levkovskyi: The intense combat gameplay has always been a standout experience that defined the original series.
Every encounter in S.T.A.L.K.E.R. 2 is designed to be life-threatening, keeping players on the edge of their seats. We've ensured that weapons behave realistically, with accurate ballistics, recoil, and damage models, preserving the gritty and unforgiving nature of combat where every shot counts. Advanced physics enhance the realism, with bullets penetrating surfaces accurately, objects reacting naturally to explosions, and enemies responding convincingly to being shot.
The AI behavior that challenged players in the original series has been improved. Enemies continue to employ clever tactics, use covers effectively, execute flanking and advancing maneuvers, throw grenades, evade threats and coordinate attacks to provide a lifetaking challenge, maintaining the tactical depth that fans loved.
For a modern audience, we've significantly upgraded AI intelligence. Enemies now make more complex decisions, assessing threats, prioritizing targets, and adapting to player strategies dynamically. This results in more engaging and unpredictable combat encounters. Additionally, enemies react more naturally to the player's presence and actions, investigating noises, responding to visible threats, and communicating with each other, creating a more immersive and lifelike combat experience.
S.T.A.L.K.E.R. 2 features a wider range of enemy types, each with unique behaviors and combat tactics, ensuring encounters remain fresh and challenging. The dynamics among different factions lead to more complex interactions and conflicts. AI-controlled factions engage in their own battles, patrols, and raids, which the player can observe or join, adding depth to the world. The transition between exploration and combat is seamless, with AI behaviors blending smoothly into the game world, keeping players constantly alert, as the line between safe and dangerous zones is often blurred.
Can you talk a little bit about the immersive survival mechanics in the game?
Levkovskyi: In S.T.A.L.K.E.R. 2, survival mechanics play a crucial role in navigating the Zone. Players must manage various negative effects to stay alive:
Levkovskyi: The intense combat gameplay has always been a standout experience that defined the original series.
Every encounter in S.T.A.L.K.E.R. 2 is designed to be life-threatening, keeping players on the edge of their seats. We've ensured that weapons behave realistically, with accurate ballistics, recoil, and damage models, preserving the gritty and unforgiving nature of combat where every shot counts. Advanced physics enhance the realism, with bullets penetrating surfaces accurately, objects reacting naturally to explosions, and enemies responding convincingly to being shot.
The AI behavior that challenged players in the original series has been improved. Enemies continue to employ clever tactics, use covers effectively, execute flanking and advancing maneuvers, throw grenades, evade threats and coordinate attacks to provide a lifetaking challenge, maintaining the tactical depth that fans loved.
For a modern audience, we've significantly upgraded AI intelligence. Enemies now make more complex decisions, assessing threats, prioritizing targets, and adapting to player strategies dynamically. This results in more engaging and unpredictable combat encounters. Additionally, enemies react more naturally to the player's presence and actions, investigating noises, responding to visible threats, and communicating with each other, creating a more immersive and lifelike combat experience.
S.T.A.L.K.E.R. 2 features a wider range of enemy types, each with unique behaviors and combat tactics, ensuring encounters remain fresh and challenging. The dynamics among different factions lead to more complex interactions and conflicts. AI-controlled factions engage in their own battles, patrols, and raids, which the player can observe or join, adding depth to the world. The transition between exploration and combat is seamless, with AI behaviors blending smoothly into the game world, keeping players constantly alert, as the line between safe and dangerous zones is often blurred.
Can you talk a little bit about the immersive survival mechanics in the game?
Levkovskyi: In S.T.A.L.K.E.R. 2, survival mechanics play a crucial role in navigating the Zone. Players must manage various negative effects to stay alive:
- Radiation: Causes continuous loss of health. Player needs to use anti-radiation drugs, vodka, or seek out areas with lower radiation levels to recover.
- Bleeding: Prevents self-health regeneration, slowly leeches health until stopped. Players need to apply bandages or use medical kits to stop the bleeding.
- Hunger: Leads to reduced endurance. Player needs to consume food regularly to maintain endurance levels.
- Sleep deficiency: Results in unfocused vision and low stamina. The player needs to ensure they get enough sleep to stay focused and maintain stamina.
The studio used an in-house engine for the first three S.T.A.L.K.E.R. games. What made you decide to move to Unreal Engine for S.T.A.L.K.E.R. 2: Heart of Chornobyl?
Maksym Yanchyi, Lead Platform Tools Programmer: Unreal Engine 5 features a suite of cutting-edge features that push the boundaries of what is possible in real-time graphics (Nanite, Lumen, Temporal Super Resolution, Virtual Shadow Maps, Niagara, and many more). Unreal Engine is known for its robust multi-platform support, which helped us to develop the game for both PC and Xbox platforms. The Editor is highly versatile, user-friendly, and customizable, which significantly enhances development efficiency.
All of this opens radically new possibilities in creating marvelous experiences for players, out of the box. Many tools are ready to be used by artists and developers, and this helped us to concentrate on more project-specific, targeted features and optimizations.
How did working on an entirely different engine impact your workflow?
Yanchyi: Many Unreal Engine systems allow artists to work independently of developers (Anim systems, materials, Profilers, visual scripting, etc.), rapidly prototype their ideas freely, and present the results to colleagues, which strengthens our iterative design paradigm. The rich system of instruments impacted our workflow in a way that we could base our development plans knowing exactly which particular things are lacking in the vanilla version and focus on that, instead of reinventing the wheel each time.
Maksym Yanchyi, Lead Platform Tools Programmer: Unreal Engine 5 features a suite of cutting-edge features that push the boundaries of what is possible in real-time graphics (Nanite, Lumen, Temporal Super Resolution, Virtual Shadow Maps, Niagara, and many more). Unreal Engine is known for its robust multi-platform support, which helped us to develop the game for both PC and Xbox platforms. The Editor is highly versatile, user-friendly, and customizable, which significantly enhances development efficiency.
All of this opens radically new possibilities in creating marvelous experiences for players, out of the box. Many tools are ready to be used by artists and developers, and this helped us to concentrate on more project-specific, targeted features and optimizations.
How did working on an entirely different engine impact your workflow?
Yanchyi: Many Unreal Engine systems allow artists to work independently of developers (Anim systems, materials, Profilers, visual scripting, etc.), rapidly prototype their ideas freely, and present the results to colleagues, which strengthens our iterative design paradigm. The rich system of instruments impacted our workflow in a way that we could base our development plans knowing exactly which particular things are lacking in the vanilla version and focus on that, instead of reinventing the wheel each time.
How did Nanite impact the development and look of the game?
Yanchyi: Nanite has allowed us to remove a large chunk of work from our artists, regarding handcrafted LOD managing and their memory footprints, and GPU pipeline bottlenecks. We achieved it not only without losing, but even winning in the final visual quality of the game. What is also important is that memory and optimization-wise, we could be happy knowing how Nanite manages resources under the hood.
Can you walk us through some of the ways the team used Lumen?
Yanchyi: Lumen gave us an ability to create stunning underground and on-ground atmospheric locations, filled with indirect lighting from our various handcrafted weather presets.
Yanchyi: Nanite has allowed us to remove a large chunk of work from our artists, regarding handcrafted LOD managing and their memory footprints, and GPU pipeline bottlenecks. We achieved it not only without losing, but even winning in the final visual quality of the game. What is also important is that memory and optimization-wise, we could be happy knowing how Nanite manages resources under the hood.
Can you walk us through some of the ways the team used Lumen?
Yanchyi: Lumen gave us an ability to create stunning underground and on-ground atmospheric locations, filled with indirect lighting from our various handcrafted weather presets.
Which other Unreal Engine 5 features significantly impacted the development and look of the game?
Yanchyi: It would definitely be the World Partition system. When you are developing an open-world game with many complex locations and nature around them you are unavoidably falling into the “change-conflict” problem in level artists' workflow. World Partition’s idea of One File Per Actor divided our life into “before and after” definitely. Our artists became able to collaborate more comfortably on different stages of location’s lifetime (greybox level-design, beautification, etc.). The Data Layer subsystem empowered us in our aim to radically change visuals of different locations, driven by narrative progression, that's a really cool and handy feature!
What advice would you give to other developers going through the process of transitioning to Unreal Engine?
Yanchyi: UE has a rich battery of pre-implemented systems and instruments: learn them and try to leverage the maximum from them and focus only on project-specific feature-development and let UE handle the rest. It really saves loads of time to go through the documentation to realize that many problems which you’ve encountered already have the production-ready solution.
Yanchyi: It would definitely be the World Partition system. When you are developing an open-world game with many complex locations and nature around them you are unavoidably falling into the “change-conflict” problem in level artists' workflow. World Partition’s idea of One File Per Actor divided our life into “before and after” definitely. Our artists became able to collaborate more comfortably on different stages of location’s lifetime (greybox level-design, beautification, etc.). The Data Layer subsystem empowered us in our aim to radically change visuals of different locations, driven by narrative progression, that's a really cool and handy feature!
What advice would you give to other developers going through the process of transitioning to Unreal Engine?
Yanchyi: UE has a rich battery of pre-implemented systems and instruments: learn them and try to leverage the maximum from them and focus only on project-specific feature-development and let UE handle the rest. It really saves loads of time to go through the documentation to realize that many problems which you’ve encountered already have the production-ready solution.
What does it feel like to finally have this game coming out after so many years of development?
Yanchyi: It’s the storm of emotions indeed, we’re working hard to ship the best possible experience, it takes a lot to make such a product, but I’m happy that we’ve gone through all this and with the product we’re going to present!
Thanks for taking the time to chat with us. Where can people go to learn more about GSC Game World and S.T.A.L.K.E.R. 2: Heart of Chornobyl?
Yanchyi: https://www.stalker2.com would definitely be a good starting point!
Yanchyi: It’s the storm of emotions indeed, we’re working hard to ship the best possible experience, it takes a lot to make such a product, but I’m happy that we’ve gone through all this and with the product we’re going to present!
Thanks for taking the time to chat with us. Where can people go to learn more about GSC Game World and S.T.A.L.K.E.R. 2: Heart of Chornobyl?
Yanchyi: https://www.stalker2.com would definitely be a good starting point!