About toolpath schemas

Schema com.autodesk.powderbed-1.0.0

The com.autodesk.powderbed-1.0.0 schema is intended as a basis for powder bed related toolpath data.

In order to be compatible with the com.autodesk.powderbed-1.0.0 schema, toolpath data must have an integer attribute bsid attached to every toolpath element (polygon, polyline, hatching) in the result bsHatch object. The bsid integer attribute should be used to typify a toolpath element (e.g. bsid set to 3 for Border - Volume toolpath elements).

Here is an example of how to declare the bsid attribute:

/**
*  Declare attributes to be stored within exposure vectors
*
* @param  buildAttrib   bsBuildAttribute
*/
exports.declareBuildAttributes = function(buildAttrib)
{    
  buildAttrib.declareAttributeInt("bsid");
};

Here is an example of how to set the bsid integer value for toolpath elements:

/**
* Calculate the exposure data / hatch vectors for one layer of a part
* @param  modelData    bsModelData
* @param  hatchResult  bsHatch
* @param  nLayerNr      int
*/
exports.makeExposureLayer = function(modelData, hatchResult, nLayerNr)
{    
  let island_it = modelData.getFirstIsland(nLayerNr);
  while(island_it.isValid())
  {
    let hatch_paths = new HATCH.bsHatch();
    island_it.getIsland().hatch(hatch_paths, 0.3, 45, 0);    
    
    // Set the bsid 7 for all elements
    // in the bsHatch object (island hatching)
    hatch_paths.setAttributeInt("bsid", 7);
    
    hatchResult.moveDataFrom(hatch_paths);
    
    island_it.getIsland().borderToHatch(hatch_paths);

    // Set the bsid 8 for all elements
    // in the bsHatch object (border)
    hatch_paths.setAttributeInt("bsid", 8);
    
    hatchResult.moveDataFrom(hatch_paths);
  
    island_it.next();
  }
  
  let polyline_it = modelData.getFirstLayerPolyline(
    nLayerNr, POLY_IT.nLayerOpenPolylines);
  while(polyline_it.isValid())
  {             
    let polyline_hatch_paths = new HATCH.bsHatch();
    
    polyline_it.polylineToHatch(polyline_hatch_paths);

    // Set the bsid 9 for all elements
    // in the bsHatch object (polylines)
    polyline_hatch_paths.setAttributeInt("bsid", 9);
    
    hatchResult.moveDataFrom(polyline_hatch_paths);
    
    polyline_it.next();
  }  
};

In addition to typifying a toolpath element with the bsid integer attribute, it is also necessary to supply laser parameter values for the toolpath element types via a customTable attribute attached to every model.

The customTable is an array of toolpath element type information objects. There must be a toolpath element type information object for every used toolpath element type (bsid integer value) in a model. A single toolpath element type information object must contain the associated bsid integer value and the laser parameters focus (mm), power (watt), speed (mm/s), and laserIndex (integer).

Here is an example of how to fill the customTable array and attach it to a model:

/**
* Prepare a part for calculation. Checking configuration
* and adding properties to the part
* @param  model   bsModel
*/
exports.prepareModelExposure = function(model)
{
  // Create custom table
  let customTable = [];
  
  // Create an object
  let bsid_obj = new Object();
  
  // Set members of the object
  bsid_obj.bsid = 7;
  bsid_obj.power = 207.0;
  bsid_obj.focus = 0.0;
  bsid_obj.speed = 1070.0;
  bsid_obj.laserIndex = 1;
  
  // Add object to custom table
  customTable.push(bsid_obj);
  
  bsid_obj = new Object();
  bsid_obj.bsid = 8;
  bsid_obj.power = 208.0;
  bsid_obj.focus = 0.0;
  bsid_obj.speed = 1080.0;
  bsid_obj.laserIndex = 1;  
  customTable.push(bsid_obj);
  
  bsid_obj = new Object();
  bsid_obj.bsid = 9;
  bsid_obj.power = 209.0;
  bsid_obj.focus = -1.0;
  bsid_obj.speed = 1090.0;
  bsid_obj.laserIndex = 1;  
  customTable.push(bsid_obj);

  // Attach the custom table to the model
  model.setAttribEx("customTable", customTable);
};

Schema com.autodesk.powderbed.renishaw-1.0.0

The com.autodesk.powderbed.renishaw-1.0.0 schema extends the com.autodesk.powderbed-1.0.0 schema by additional laser parameters for the Renishaw machines.

Additional laser parameters pointDistance (micrometer) and pointExposureTime (microseconds) can be given. If pointDistance and pointExposureTime is needed by the exporter and the two parameters are not given, then the exporter has to try to automatically derive the parameter from power and speed. However, it is recommended that the toolpath calculation provides pointDistance and pointExposureTime. It is possible that the automatic derivation from power and speed produces unwanted results and the user does not know how to make it work as expected.

Here is an example of how to fill the customTable array for the com.autodesk.powderbed.renishaw-1.0.0 schema and attach it to a model:

/**
* Prepare a part for calculation. Checking configuration
* and adding properties to the part
* @param  model   bsModel
*/
exports.prepareModelExposure = function(model)
{
  // Create custom table
  let customTable = [];
  
  // Create an object
  let bsid_obj = new Object();
  
  // Set members of the object
  bsid_obj.bsid = 7;
  bsid_obj.power = 260.2;
  bsid_obj.focus = 0.0;
  bsid_obj.speed = 400.5;
  bsid_obj.pointDistance = 4.2342;
  bsid_obj.pointExposureTime = 0.3471;
  bsid_obj.laserIndex = 1;
  
  // Add object to custom table
  customTable.push(bsid_obj);
  
  bsid_obj = new Object();
  bsid_obj.bsid = 8;
  bsid_obj.power = 290.1;
  bsid_obj.focus = 1.2;
  bsid_obj.speed = 350.0;
  bsid_obj.pointDistance = 2.0112;
  bsid_obj.pointExposureTime = 0.9284;
  bsid_obj.laserIndex = 1;  
  customTable.push(bsid_obj);
  
  bsid_obj = new Object();
  bsid_obj.bsid = 9;
  bsid_obj.power = 260.2;
  bsid_obj.focus = 0.0;
  bsid_obj.speed = 400.5;
  bsid_obj.pointDistance = 4.2342;
  bsid_obj.pointExposureTime = 0.3471;
  bsid_obj.laserIndex = 1;  
  customTable.push(bsid_obj);

  // Attach the custom table to the model
  model.setAttribEx("customTable", customTable);
};