3D Data Concepts¶
instant3Dhub distinguishes several key aspects of 3D data. Each aspect focuses on a different element of the model:
Structure: The hierarchical organization of assemblies and parts, describing how pieces fit together.
Geometry: The mathematical definitions of shapes and surfaces, commonly stored as tessellated data or B-Rep.
PMI & Model Views: Manufacturing-related annotations (e.g., tolerances) and predefined perspectives or filter states that enhance understanding of the 3D scene.
Metadata: Supplementary information, such as names, materials, versioning, or access rights, that describes or manages the model.
Layer: TBD
Detailed explanations of these categories are provided in the sections below.
Structure¶
In most CAD and 3D systems, structure refers to how 3D data is organized and linked. This hierarchy allows larger assemblies to be built from smaller, reusable parts and defines how each of them fits together in the overall design.
Assemblies: An assembly is the top-level container that references one or more parts (or sub-assemblies). Assemblies store transformation information (e.g., position, orientation) so that each part or sub-assembly is placed correctly relative to others.
Parts: A part is a self-contained unit within an assembly, containing the actual geometric definitions needed to represent a component. Parts can be reused in different assemblies, reducing duplication.
Bodies: Bodies are the basic building blocks within parts. Each body holds its own geometry, and multiple bodies can be combined or modified to form the final shape of a part.
This structure is preserved in instant3Dhub, enabling the navigation, transformation or selective display of parts and assemblies.
Geometry¶
Geometry defines the shape of objects in a 3D environment. It is the foundation of all 3D models and is used to represent the physical appearance of objects in a scene. instant3Dhub interprets the following basic types of geometric entities and types of geometric data used to represent these entities (refer to our instant3Dhub documentation for technical information).
Basic types of geometric entities¶
Points: Zero-dimensional entities defined by a single coordinate,
Edges: One-dimensional entities connecting two points,
Faces: Two-dimensional surfaces bounded by edges and
Shapes: Three-dimensional entities composed of multiple faces.
UX-Flow leveraging geometric information can be build with e.g. the TopologyAPI.
Types of geometric descriptions¶
When describing 3D shapes, there are typically two main ways to store and communicate geometry, balancing precision and computational efficiency:
Tesselated Data: Contains polygonal approximations represented by meshes composed of vertices, edges, and faces.
Boundary Representation (B-Rep): Represented by a set of 3D geometry objects and curves that define the boundaries of a solid object.
Product Manufacturing Information & Model Views¶
Besides the standard structure and geometry, instant3Dhub also handles Product Manufacturing Information (PMI) (treated as part of auxiliary information in instant3Dhub) and Model Views. Both are both related to geometry and explained in the following:
PMI: They consist of non-geometric data in CAD models used to describe requirements for manufacturing, tolerances, surface qualities etc.
Model Views: These are predefined camera positions, visibility states and section cuts, enabling the automatic toggling of nodes.
Metadata¶
Metadata refers to information that describes or contextualizes other data, and typically falls into one or more of the following categories:
Descriptive metadata: Part names, material, creator, version
Structural metadata: Assembly hierarchy, relationships between components
Administrative metadata: File format, access permissions, timestamps
instant3Dhub generally considers and makes use of the available metadata types (refer to our ContextAPI for technical information).
Layer¶
TBD