Crowd simulation' is the process of simulating the movement of a large number of objects or characters, now often appearing in 3D computer graphics for film. A 3D rendering with raytracing and ambient occlusion using Blender and Yafray 3D computer graphics are works of graphic art created with the aid of digital computers and 3D software. ... This article is about motion pictures. ...

The need for crowd simulation arises when a scene calls for more characters than can be practically animated using conventional systems, such as skeletons/bones.

Animators typically create a library of motions, either for the entire character or for individual body parts. To simplify processing, these animations are sometimes baked as morphs. Alternatively, the motions can be generated procedurally - i.e. choreographed automatically by software. Morph could relate to the following : Morph, an animated plasticine character often featured in Tony Harts television programmes. ...

The actual movement and interactions of the crowd is typically done in one of two ways:

• Particle Motion: The characters are attached to point particles, which are then animated by simulating wind, gravity, attractions, and collisions. The particle method is usually inexpensive to implement, and can be done in most 3D software packages. However, the method is not very realistic because it is difficult to direct individual entities when necessary, and because motion is generally limited to a flat surface.

• Crowd AI: The entities - also called agents - are given artificial intelligence, which guides the entities based on one or more of sight, hearing, basic emotion, energy level, aggressiveness level, etc.. The entities are given goals and then interact with each other as members of a real crowd would. They are often programmed to respond to changes in environment, enabling them to climb hills, jump over holes, scale ladders, etc. This system is much more realistic than particle motion, but is very expensive to program and implement.

The most notable examples of AI simulation can be seen in New Line Cinema's The Lord of the Rings films, where AI armies of many thousands battle each other. The crowd simulation was done using Weta Digital's Massive software. For more background on this topic, see game physics. ... Wind is the rough horizontal movement of air (as opposed to an air current) caused by uneven heating of the Earths surface. ... Gravity is a force of attraction that acts between bodies that have mass. ... In computer science, a software agent is an abstraction, a logical model that describes software that acts for a user or other program in a relationship of agency. ... Hondas humanoid robot AI redirects here. ... New Line Cinema logo New Line Cinema, founded in 1967, is one of the major American film studios. ... This article is about the novel by J. R. R. Tolkien. ... Weta Digital is a digital visual effects company based in Wellington, New Zealand, an offshoot of the Weta Workshop physical effects company. ... The Massive user interface A battle simulated using Massive Massive (Multiple Agent Simulation System in Virtual Environment) is a high-end computer animation and artificial intelligence software package used for generating crowd-related visual effects for film and television. ...

Crowd simulation can also refer to simulations based on group dynamics and crowd psychology, often in public safety planning. In this case, the focus is just the behavior of the crowd, and not the visual realism of the simulation. The term group dynamics implies that individual behaviours may differ depending on individuals current or prospective connections to a sociological group. ... Ordinary people typically can gain direct power by acting collectively. ...

See also

• 3D computer graphics
• Artificial intelligence
• Emergent behavior
• MASSIVE (animation)
• Multi-agent system
• Particle system
• AgentSheets

A 3D rendering with raytracing and ambient occlusion using Blender and Yafray 3D computer graphics are works of graphic art created with the aid of digital computers and 3D software. ... Hondas humanoid robot AI redirects here. ... Emergence is the process of deriving some new and coherent structures, patterns and properties in a complex system. ... The Massive user interface A battle simulated using Massive Massive (Multiple Agent Simulation System in Virtual Environment) is a high-end computer animation and artificial intelligence software package used for generating crowd-related visual effects for film and television. ... In computer science, a multi-agent system (MAS) is a system composed of several agents, capable of reaching goals that are difficult to achieve by an individual system. ... For more background on this topic, see game physics. ... AgentSheets is an easy to use game and simulation authoring tool. ...

External links

• BlenderPeople, free software for crowd simulation usable with the Blender animation suite
• NetLogo, a free software for multi-agent modeling, simulation, and the like.
• MASSIVE, the software used in The Lord of the Rings films.
• CrowdIT, Crowd tool for 3d studio Max
• SpirOps Crowd, Crowd tool and IA middleware used in Splinter Cell - Double Agent game.
• Micro-PedSim, microscopic (multi-agents) pedestrian traffic simulation.