Unity is a game engine and development environment for creating 2D and 3D games and interactive applications on Windows, macOS, and Linux. Its Editor brings scene construction, C# programming, graphics, sound, and game builds into one project. You can arrange the world visually, give its objects behavior, and run the result inside the Editor before producing a playable application.
GameObjects
Unity separates the assets belonging to a project from the objects used in a particular scene. The Project window holds files in folders, including assets that have not been placed in the world. The Hierarchy window shows the current scene’s GameObjects, with parent and child relationships for organizing related objects. Selecting an object brings its settings into the Inspector.
Components define what a GameObject contains and how it behaves. The Inspector exposes these components and their properties, including an object’s position, rotation, and scale. In the Scene view, you can inspect the environment from different angles and manipulate its contents visually. Cameras determine the view presented to the player, while terrain tools provide landforms and vegetation for larger environments.
C# scripts
Unity uses C# and .NET for scripting, with support for development tools such as Visual Studio and JetBrains Rider. A script can be attached to a GameObject as a component, connecting custom behavior with the object you configure in the Editor. This is how a project can go beyond arranging a scene to implement movement, player controls, and interactions.
Input support spans keyboards, mice, gamepads, touchscreens, and headsets. The input handling and the response it triggers remain part of the game’s design: a controller script can turn player input into movement, while the component settings provide values that the author can adjust without changing the scene’s layout.
Object physics
Unity handles an object’s visible shape and physical behavior through different components. A Rigidbody gives a 3D object mass and a response to gravity, while a collider defines the boundaries used when it hits another object. A Physics Material controls behavior such as bouncing on impact, separately from the material used to color the object’s surface.
For flat games, Unity supplies separate Rigidbody 2D and collider components. A wall sprite needs a 2D collider if it is to stop a moving character. Gravity can be adjusted independently, allowing an overhead game to use physical interactions without making every object fall down the screen. The component choices therefore need to match the project’s 2D or 3D physics system.
Sprite animation
Unity’s 2D Scene view works on the horizontal and vertical axes, with panning and zooming for arranging flat artwork. Sprites represent characters, scenery, and other objects. You can drag these graphics into the scene and use the Rect tool to position and reshape them.
The Sprite Editor turns an image containing multiple animation frames into individual sprites. After setting the image to use multiple sprites, you can slice the sheet and use the resulting frames to create an Animation file. That file controls the sequence of images displayed by the object.
This lets a 2D character move visually while remaining a GameObject with its own physics and scripts. Animation alone does not create collision behavior; those interactions still depend on the object’s components. Unity also provides a 3D character animation toolset for animated characters and cutscenes.
Rendering
Materials and shaders control how objects appear. A material is a reusable project asset that you can apply to objects in different scenes. Its properties can include base color, metallic appearance, and smoothness, so changing a surface involves more than replacing its color. Lighting then shapes how those surfaces appear within the environment.
Unity includes multiple render pipelines, including the Universal Render Pipeline for projects targeting a range of devices. Particle systems supply animated effects such as steam and bubbles within the scene. Post-processing works on the rendered image, applying full-screen effects to the camera output.
Spatial audio
An Audio Source component plays a sound clip from the project, with settings for volume and looping. The Spatial Blend control determines whether it behaves as 2D or 3D audio. A background music source can stay at a consistent level as the player moves, while a sound assigned to a world object can change with the listener’s position and orientation.
The Audio Listener supplies that listening point, commonly on the camera. This gives a 3D scene both a visual viewpoint and an audio perspective: approaching a source can make it louder, and turning relative to it changes its direction. Unity also provides real-time mixing, mixer hierarchies, and audio effects for managing the combined sound.
Testing and profiling in the Editor
The Game view shows the scene through its camera. Entering Play mode runs the application there, so you can try controls and interactions while developing. Its aspect-ratio settings also help you inspect how the camera output fits different screen shapes. Changes made during Play mode are temporary, and stopping the application returns you to scene editing.
Unity’s Profiler displays performance data in charts to help identify areas consuming resources. The Frame Debugger examines rendered frames when investigating visual problems or rendering work.
Target platforms and Unity editions
Build Profiles select the platform for the playable output. Switching targets prepares the project’s assets and settings for that destination; creating a build then packages the game to run outside the Unity Editor. Supported destinations include desktop computers, mobile devices, the web, consoles, and XR devices, with availability depending on the target and license.
Unity Personal provides the engine free to eligible games and entertainment creators, with publishing to desktop, mobile, web, and AR/VR targets. Unity Pro adds console and Apple Vision Pro publishing, along with support and cloud features. Enterprise adds facilities such as build automation and read-only source access. Industrial applications use different licensing rules from games and entertainment projects.
