A: This is a frequently asked question particularly with the current capabilities of computers and animation. We cover the topic in 3D or Not 3D
In accident reconstruction,
- Animation is often used to illustrate an opinion. Animations generally use spline fit techniques to visually match movements of vehicles. Animation by itself does not test whether the movements and responses are physically possible, meaning whether or not they obey Newton’s Laws of Motion
- Simulation is used in accident reconstruction to test and refine an opinion. Simulations are mathematical models which attempt to apply and follow Newton’s laws of Motion. Simulations can be used as the basis for an Animation meaning the mathematically simulated motion can be used in an animation to move the objects (for example, to move vehicles colliding, etc).
- The inputs should be fully revealed and checked. See 3D or Not 3D for a presentation of what you need to request when faced with a Simulation or Animation.
For simulations you also need to verify if the model has been tested and validated and if the type of vehicle movement or collision interaction are consistent with the validations. All too often we find ‘experts’ misusing simulation models. For example see our discussion on the ATB simulation model and our discussion 3D or Not 3D for some related discussion on validation and simulation models.
- From the web Animation
- "is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. It is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in a number of ways. The most common method of presenting animation is as a motion picture or video program, although several other forms of presenting animation also exist".
- "is the imitation of some real thing, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviors of a selected physical or abstract system. Simulation is used in many contexts, including the modeling of natural systems or human systems in order to gain insight into their functioning. Other contexts include simulation of technology for performance optimization, safety engineering, testing, training and education. Simulation can be used to show the eventual real effects of alternative conditions and courses of action. Key issues in simulation include acquisition of valid source information about the relevant selection of key characteristics and behaviours, the use of simplifying approximations and assumptions within the simulation, and fidelity and validity of the simulation outcomes".