Rockstar recently announced that GTA 6 employs a real-time animation retargeting system that adjusts movements based on each NPC's height and body type. With this system, the game can create characters with more distinct physical differences while ensuring smooth transitions for actions such as combat, vehicle entry, and character interactions.
Rob Nelson, co-head of Rockstar Studios, stated that NPCs in this game will exhibit greater variation in height and body type than in previous entries in the series. Past GTA games required characters with different body proportions to share animations, which imposed certain limitations on character design.
When two characters with significant height differences use the same set of animations, issues may occur during interactions with other characters or the environment. Instead of creating separate animation sets for every body type, the new system dynamically retargets animations at runtime to better fit the current NPC's body proportions.
This technology will be used in scenarios such as NPC combat, entering vehicles, riding in cars, and interacting with other characters. For example, when two characters of different heights engage in a conflict, their animations need to be adjusted based on their respective proportions. Similar issues arise when characters interact with vehicles and other environmental objects.
The "Greet or Antagonize" interaction system from Red Dead Redemption 2 will also return in this title. Differences in NPC body types will be integrated into these interactions, resulting in varied reactions when characters face protagonists Jason and Lucia, as well as others around them.
Character body types also influence clothing and overall appearance, while facial shapes and sizes affect details like hairstyles and expressions. Rockstar hopes to increase the diversity among pedestrians, drivers, and other characters on the streets of Vice City, reducing the impression that many NPCs are merely slight variations of the same character model.
Nelson stated that the team aims to make this game world Rockstar's largest, deepest, most densely populated, and most complex to date. The real-time animation retargeting system provides greater flexibility for character design, allowing NPCs of different builds to participate together in various open-world interactions.