The 2.5D, or three-quarter, or preudo-3D, animation is a distinct type of animation that involves the combination of 2D objects in the 3D space for the creation of a 3D space impression. This animation technique is traditionally applied in the video game industry to create 2D graphical projections and other objects to simulate 3D. In a nutshell, 2.5D animation is thus the 2D animation in the 3D space. Other spheres of its application include title sequences, icon and GUI design, and music video production.
2.5D animation can be created by means of moving 2D objects in 3D space (both physically or with the help of computer program) or through a wise application of perspective and shadows to change the way 2D objects look. Shading is a popular technique of adding 3D volume to an object; this can be done by casting a shadow from the object onto its background, or by creating twin objects and greying them out. With proper arrangement of objects in the 3D space, the 2D objects will obtain the required depth for the 3D illusion creation. Other methods for creating the 2.5D animation include the axonometric and oblique projection, billboarding, the use of skyboxes and skydomes, parallax scrolling, and scaling along the Z axis.