Glossary

Term	Description
Entity	Any abstract object that is defined by a unique ID. In Pixyz, the entity is the base object. All manipulated objects are derived from entities. For example, parts, materials, and textures are entities. IDs are not consistent between file imports (meaning that if you import the same file twice there is no guarantee that Occurrence X will have the same id accross imports).
Occurrence	A node in the product structure. In Unity, occurrences are referred to as GameObjects.
Product structure	The scene hierarchy of occurrences. In Unity, the product structure is referred to as the hierarchy of GameObjects.
Instance	An occurrence that inherits (and override) properties and components from a prototype occurrence. Instances are usually defined in modeling software. Pixyz IO functions natively handle defined instances but new ones can be created using scene.setPrototype or algo.convertSimilarPartOccurrencesToInstancesFast.
Prototype	An occurrence referenced by another occurrence as its prototype. Occurrences that point to a prototype are instances. Prototypes can be instanciated using scene.prototypeSubTree.
Component	A behavior attached to an occurrence.
Part	A component referencing geometry information. In Unity, parts are referred to as renderers.
Geometry	A collection of shapes. Geometries may be CAD geometries (B-Rep shapes) or mesh geometries (tessellated shapes).
Patch	A CAD face or surface that is limited by spline curves. Patches have no strict equivalent in Unity. The concept of submesh in Unity is the closest.
Polygon	A triangle, a quadrangle, or another simple convex polygon (n-gon). In Unity, all polygons are triangles.
Polygon mesh	A collection of vertices, edges, and faces.
Material	An entity that contains visual definitions. Its properties depend on its associated material pattern. A material can be referenced by an occurrence or a Part component.
Octree	An internal Pixyz spatialization structure helping algorithms perform faster.