Virtual Learning Factory Toolkit
  • Virtual Learning Factory Toolkit
  • VLF Knowledge Base
    • Factory Data Model
      • OWL Classes
      • SPARQL Queries
      • SPARQL Updates
    • Instantiation of Factory Models
      • Assets
        • Assets in Spreadsheet
        • Assets in JSON
        • Assets in Ontology
      • 3D Models of Assets
        • 3D Models for Virtual Reality
      • Statechart
      • Animations
      • Data Repositories
        • Local Repository
        • Remote Repository
  • VLF Tools and Libraries
    • OntoGui
      • Modules
        • Control Panel
        • Individual Manager
        • System Design
        • Utilities
      • Personalization
    • OntoGuiWeb
      • Modules
        • Control Panel
        • SPARQL
        • Graphs OWL
        • Utilities
        • Asset Design
        • System Design
        • System Control
        • Performance Evaluation
        • MQTT Sync
        • Virtual Environment
        • Graphs Eng
        • StateChart
      • Personalization
    • jsimIO
      • How to start
      • JMT Overview
        • JSim
          • Model generation
          • Launch of the simulation
          • Reporting
        • Bibliography
    • VEB.js
      • Functionalities
      • Input/Output files
      • Integration with other software tools
      • Advanced Users
    • ApertusVR
    • MTM
      • How to start
      • Formalise the process
      • Prepare input data
      • Execution and results
    • MOST
      • How to start
      • Formalise the process
      • Prepare input data
      • Execution and results
    • RULA
      • How to start
      • Formalise the process
      • Prepare input data
      • Execution and results
    • OCRA
      • How to start
      • Prepare input data
      • Execution and results
  • Use Cases
    • Automated Assembly Line
    • Assets and Animations
    • Modelling of Factory Assets
      • Modelling of an Assembled Product
      • Modelling of a Workstation
      • 3D Modelling of a Workstation for Virtual Reality
    • Process Modelling
      • Modelling an Assembly Process
    • Modelling of a manufacturing system
      • Modelling in OntoGui
      • Modelling a Job Shop using OntoGui
      • Modelling of a Flow Shop using OntoGui
      • Modelling a Hybrid Flow Shop using OntoGui
      • Modelling an assembly system using OntoGui
    • Performance evaluation using jsimIO
      • Performance evaluation of a manufacturing system
        • Performance evaluation in Jsim
        • Performance evaluation of a Flow Shop using Jsim
        • Performance Evaluation of a Job Shop using JSim
        • Performance evaluation of a Hybrid Flow Shop using Jsim
        • Performance evaluation of an assembly system using Jsim
      • jsimIO Assembly
      • jsimIO Automatic
      • jsimIO Production
  • Classworks
  • Advanced Features
    • JMT model
      • Automatic generation of a JMT model
      • Automatic generation of animations
    • Enabling technologies
      • Node-RED
        • Node-RED tutorial
      • RDF libraries
Powered by GitBook
On this page
  • Scaling and orientation
  • Grouping and referencing
  • Setting up the origin
  • Formalize information of assets using 3D models

Was this helpful?

  1. VLF Knowledge Base
  2. Instantiation of Factory Models

3D Models of Assets

PreviousAssets in OntologyNext3D Models for Virtual Reality

Last updated 4 years ago

Was this helpful?

Assets composing a model of a factory also need to be modeled in terms of their 3D representation. To go in this direction, 3D models must be available. They can be obtained according to two main options:

  1. Use existing 3D models. 3D models of industrial objects are often available in online databases (e.g., ) or directly provided by OEMs in official catalogs. These models are usually very detailed, thus an aspect to be considered is being able to end up with manageable models in terms of dimension and complexity. Furthermore, 3D models must be available in a neutral format (e.g. .STEP or .IGES), so that they can be easily imported in general software environments for further processing. IMPORTANT: 3D models downloaded from external sources are often constrained by privacy policies and rights preventing some or all their possible uses. This can prevent the possibility to publish this material on this website, even if not commercial use is foreseen. Please, before proceeding, check information about and favor open licensing schemes.

  2. Generate 3D models. A second option is to generate 3D geometries using CAD modeling tools (e.g. , ). Although more difficult and time-consuming, consider this option to avoid possible issues related to licensing and rights.

Scaling and orientation

3D models in the scene have to be properly scaled. The hypothesis, unless differently specified, is that all the measures are expressed in millimeters (mm).

Furthermore, the orientation of each single component must be coherent with the other objects in the scene. In many CAD environments, it is possible to specify the convention used for the orientation of the z-axis (z-up option).

Grouping and referencing

Assets in a factory are often complex objects consisting of many components assembled together (e.g., a workstation). It is important to build 3D models in order to be easily and clearly composed to form complex assets.

It's important to have a univocal reference point for each asset in the scene. Namely, this point is the origin of the corresponding 3D model. Origins may often have unusual positions, especially when 3D models have been downloaded from online databases. To make the use and re-use of 3D models in the scene coherent, a reasonable solution is setting the origin in the central point of the bottom face of the bounding box of the component.

The positions of the origins can be used to define a complex asset by specifying the relative position of its components according to the following steps:

  1. Each complex asset will have a parent empty object to which its static components will be referenced and positioned.

  2. Subcomponents have to be grouped matching the hierarchy of the assembly, i.e., assets forming a sub-assembly must be grouped together.

  3. Parenthood relationships between the 3D models have to be defined specifying the associate relative positioning. CAD environments use this approach to manage multipart assemblies and dependencies.

Setting up the origin

This operation can be accomplished in CAD software such as Solidworks, or downstream when editing the exported GLTF/OBJ in Blender.

  1. Generate the bounding box of the 3D model.

  2. Make the central point of its bottom face explicit.

  3. Move the origin to make it coincident with the point.

Formalize information of assets using 3D models

  • the placement (either position or rotation) is customized with respect to the default values defined in the 3D model file (e.g. GLTF file)

The described procedure and conventions are used to derive information on 3D models to support the by specifying their representation. It must be stressed that not all components in an aggregated object must be necessarily mapped to assets instantiated in the digital model (, or ). Indeed, this mapping should be limited to components that are associated with needs in the following (non-exhaustive) list:

a description or any other property (type, model, connection, assignment) must be defined, as documented for and .

the component must independently of its parent. Static components typically are not associated with this need.

Please note that if a component is explicitly defined as an instantiated asset, then also its parent must be explicitly defined for the sake of consistency. In addition, a unique reference to the component inside the 3D model must be provided (e.g. adding '#componentID' to the file name, cf. "file" property in and ). This means that also the ID of components in the 3D model must be uniquely identifiable.

Examples are provided in the for an and a .

instantiation of assets
spreadsheet
JSON
ontology
animated
use case section
assembled product
workstation
GrabCAD
licenses
Solidworks
Inventor
JSON files
spreadsheets
JSON file
spreadsheet
Standard positioning of the origin for a 3D model.