Intelligent Camera Control Using Behavior Trees

Abstract

Automatic camera systems produce very basic animations for virtual worlds. Users often view environments through two types of cameras: a camera that they control manually, or a very basic automatic camera that follows their character, minimizing occlusions. Real cinematography features much more variety producing more robust stories. Cameras shoot establishing shots, close-ups, tracking shots, and bird's eye views to enrich a narrative. Camera techniques such as zoom, focus, and depth of field contribute to framing a particular shot. We present an intelligent camera system that automatically positions, pans, tilts, zooms, and tracks events occurring in real-time while obeying traditional standards of cinematography. We design behavior trees that describe how a single intelligent camera might behave from low-level narrative elements assigned by "smart events". Camera actions are formed by hierarchically arranging behavior sub-trees encapsulating nodes that control specific camera semantics. This approach is more modular and particularly reusable for quickly creating complex camera styles and transitions rather then focusing only on visibility. Additionally, our user interface allows a director to provide further camera instructions, such as prioritizing one event over another, drawing a path for the camera to follow, and adjusting camera settings on the fly.We demonstrate our method by placing multiple intelligent cameras in a complicated world with several events and storylines, and illustrate how to produce a well-shot "documentary" of the events constructed in real-time. Disciplines

Penerapan Sinematografi Dalam Penempatan Posisi Kamera Dengan Menggunakan Logika Fuzzy

“…Penelitian yang lain juga menggunakan metode behavior tree untuk menerapkan kaidah sinematografi. Respons kamera virtual terhadap lingkungan dan aksi akan disimpan dalam sebuah smart events [18]. Penelitian lain yang cukup berkaitan dengan penelitian ini yaitu penelitian yang mengusulkan sebuah bahasa semi otomatis untuk melakukan kontrol terhadap kamera virtual dalam lingkungan virtual [19].…”

Virtual Camera Movement with Particle Swarm Optimization and Local Regression

“…Markowitz et al [20] used the behavior tree to describe how a single camera behaves like cinematographer assigned by smart events. Behavioral response and parameter information inside the event are stored in "smart events".…”

“…Burelli et al [19] employed artificial potential fields to control both camera location and aim direction. Markowitz et al [20] presented a successful attempt to give the game designer a more robust way to customize the portrayal of the game and to give the user the ability to create complex camera transitions to provide a more engaging game experience. Galvane et al [21] used steering behavior approach to control collection of camera agents.…”

VIRTUAL-ME: A Library for Smart Autonomous Agents in Multiple Virtual Environments

“…Among the possible behaviour management models, several researchers recommend the use of the Behaviour Trees (BTs). The Behaviour Tree is a "simple data structure that provides graphical representation and formalisation for complex actions" [6]. The first implementation of BTs appeared in 2004 in a one-act interactive drama called Façade, and since then, they have been increasingly used by game AI programmers to create more exciting and complex characters.…”