Exploring 3D model contents

The contents of the loaded 3D model (represented with ModelData_Model) can be explored in memory. Depending on an input file format, a 3D model may contain:

• Product structure (or scene graph): a hierarchy of assemblies and parts, and instances thereof;
• Names and appearances (e.g. colors and materials) attached the graph elements;
• User-defined properties (string, integer or double precision numbers, dates, etc);
• Geometrical representations of the parts, for instance, meshes;
• PMI (Product and Manufacturing Information).

The product structure of the loaded 3D file can be explored using the scene graph element visitor. The visitor class which must subclass cadex.ModelData_SceneGraphElementVisitor and redefine methods visitPart(), visitAssemblyEnter(), visitAssemblyLeave(). The following example demonstrates creation of a custom visitor and applying it to the model:

class SceneGraphVisitor extends cadex.ModelData_SceneGraphElementVisitor {
  ...
  async visitElement(theElement) {
    this.info += formatKeyValue('Uuid', theElement.uuid);
    this.info += formatKeyValue('Name', theElement.name);
    ...
  }
 
  async visitPart(thePart) {
    await this.visitElement(thePart);
    ...
  }
  ...
}
 
const aVisitor = new SceneGraphVisitor();
await aModel.accept(aVisitor);
...

In a similar way, parts can be explored for available representations:

class RepresentationVisitor extends cadex.ModelData_RepresentationVisitor {
  async visitBRepRepresentation(theBRepRep) {
    ...
  }
  async visitPolyRepresentation(thePolyRep) {
    ...
  }
}
 
const aRepVisitor = new RepresentationVisitor();
await thePart.acceptRepresentationVisitor(aRepVisitor);
...

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Refer to the Model explorer example that demonstrates various techniques to retrieve data from the loaded 3D model.