Visual effects are effects added to either filmed or animated moving images, in a way to enhance them and make them more exciting and visually appealing. Most visual effects are completed during post production phase of video production if the film is made using recording video. If you are making an animated film, the special effects are made in conjunction with the characters, although the visual effects generally come after the characters have been made.
Examples of of visual effects
Particle movement like, grains for simulation sand or snow, Fluid particle which allows you to create liquids like water, or lava, for example.
Scattering – creating explosions or movement from one point to another.
What are the advantages to creating digital effects?
The advantage of creating effects digitally is that you can create environments that look realistic, but would be very dangerous, require huge amounts of space and be impractical if you were to try the same capturing it on film. Creating visual effects, although still very expensive and time consuming (in a different way), can now all be created and controlled from an office environment, safely and more precisely.
There are hindrances with digital effects still.
These processes are very heavy on processing and some computers will need RAM of 256 GB for example. For example, before you render something you have to cache all of your created simulations, and one frame can take up 1 gb of data, so a standard household computer will not be able to process it!
Rendering and creating a video from this is often done across different computers. For example the first few seconds could be done one in system, the next few seconds could be on another system. Rendering is time consuming and splitting the work in this way speeds up the process.
What is the software used?
Creating visual effects can be executed by multiple pieces of software, all serving different functions in the process. Houdini, is the name of one software used to create visual effects, which is most known for its advanced dynamic simulation tools which allow for the creation of highly visual realistic visual effects. You can create light settings like direction of light, scatter effects, movement, reflections and more. The framework for models is created in a software called Maya. This software can build characters, structures and more.
Arnold is the render engine that you can use to render the images created in Houdini, this will create the final video with effects. Mantra is another render engine which comes inside Houdini.