dotXSI is an ASCII

ASCII

The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...

 file format

File format

A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...

 of Softimage

Softimage

Softimage, Co. was a company located in Montreal, Quebec, Canada that produced 3D animation software. Their flagship products, Softimage 3D and Softimage XSI, are used in the creation of computer animation for films, television advertisement, and video games...

 Corporation for storing scene data.

It includes support for mesh

Mesh

Mesh consists of semi-permeable barrier made of connected strands of metal, fiber, or other flexible/ductile material. Mesh is similar to web or net in that it has many attached or woven strands.-Types of mesh:...

es, NURBS, 2D and 3D chains, polygon

Polygon

In geometry a polygon is a flat shape consisting of straight lines that are joined to form a closed chain orcircuit.A polygon is traditionally a plane figure that is bounded by a closed path, composed of a finite sequence of straight line segments...

s, materials, hierarchies, skeletons, animation

Animation

Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways...

 constraints, Hermite spline

Hermite spline

In the mathematical subfield of numerical analysis, a Hermite spline is a spline curve where each polynomial of the spline is in Hermite form.-See also:*Cubic Hermite spline*Hermite polynomials*Hermite interpolation...

s, custom effects, and user data.

Common applications are architecture

Architecture

Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art...

 design and video games, becoming popular after Valve pioneered its use in HalfLife2.

It was based on the Microsoft 'x-file' ascii format, extended to handle much of its specific data structures.
The 'crosswalk' SDK includes the ability to transfer data between dotXSI files and the formats of other autodesk products.