What is VFX?
Wikipedia says:“Visual effects involve the integration of live-action footage and generated imagery to create environments which look realistic, but would be dangerous, costly, or simply impossible to capture on film. Visual effects using computer generated imagery has recently become accessible to the Independent filmmaker with the introduction of affordable animation and compositing software.
So basically, anything that’s difficult to film then we use visual effects to achieve it. For example, aliens attacking the earth is impossible to film so we use visual effects for all the alien creatures to destroy the city. This is a very obviously example of visual effects. A lot of time we use visual effects in more subtle areas. For example, if there’s a scene in the story that needs to be in another country, an imaginary location or a city in the future/past. It’s just inefficiency to go to another country or build a set. Visual effects in these situation are really helpful.
Examples:
