Reactor enables you to simulate collisions between objects in a scene based on physical parameters and properties that you set for the objects. The overall shape of objects can have an effect on the calculation times, but you can optimize the process by choosing a simpler bounding shape, such as a box or sphere, to be used in the collisions instead of the complex object itself.
You learned to set up several types of object collections that define a class of behavior and define individual properties for the objects in each class. Along the way, you learned the following concepts and techniques:
Background image You learned to add an image as a background in the rendering and in the viewport to reduce geometry for faster renderings.
Compositing Rendering a background image behind a 3D scene is known as compositing; this skill is important for building complex scenes from layers composited over one another.
Matte/Shadow material To create the illusion that a background image is a physical part of the scene, you learned to use this material to make certain objects "invisible" to the rendering and let the background image show through but still receive shadows.
Rigid bodies You learned to make these objects unyielding so that they do not move in a Reactor simulation. You can add objects directly to a Rigid Bodies collection.
Cloth collections You learned to add a Reactor Cloth modifier to the Net object so that could be added to the Cloth collection.
Rope collections You learned how to apply the Reactor Rope modifier to objects so that they could be included in the Rope collection. You learned to apply the modifier to the whole rope object, and then use the SplineSelect and Reactor AttachToRB modifiers to anchor one end of the rope to a bar called Cylinder01 in the scene.
Mass properties Setting and changing the weight of objects used in collisions can greatly influence the outcome of Reactor simulations.
Keyframes and Dynamics animation You learned to animate an object for a few frames, and then set the Reactor simulation to begin its calculation at one of the animated frames to pick up the object's initial velocity for collisions.