Production Assist Core Integration (v1)#

Overview#

Starting with Production Assist Desktop App v1.14, third-party applications can run Production Assist core calculations by:

1. Writing a glTF/GLB file (glTF 2.0) enhanced with the PA_model extension.
2. Launching Production Assist Desktop App via a custom URL scheme and passing:
   • the input file path (file)
   • the output file path (file_back)
3. Reading the calculation result written as a JSON file to disk.

This is a file-based request/response integration. Production Assist acts as the processor.

---

Compatibility#

• Minimum Production Assist Desktop App version: 1.14
• Input format: .gltf or .glb (glTF 2.0)
• Output format: .json

---

1) Invocation API (Custom URL Scheme)#

URL Scheme#

Production Assist Desktop App registers the following URL scheme:

productionassist://production_assist_calculate?file=...&file_back=...

Query Parameters#

Name	Required	Type	Description
file	✅	string	Path to the input .gltf/.glb file on disk.
file_back	✅	string	Path where Production Assist will write the output .json result.

Path Rules (Important)#

• Use absolute paths whenever possible.
• The parameter values must be URL-encoded (spaces, #, ?, &, non-ASCII, etc.).
• Prefer forward slashes in URLs. If you must pass Windows paths, ensure proper encoding.

Example (conceptual):

productionassist://production_assist_calculate?file=C%3A%5Ctemp%5CCCP.glb&file_back=C%3A%5Ctemp%5CCCP.json

Processing Workflow#

1. Your application creates a .gltf or .glb file containing the PA_model extension and saves it to disk.
2. Your application opens the custom URL above (e.g., via shell open, Process.Start, etc.).
3. Production Assist Desktop App loads the input file, performs calculations, and writes a JSON result to file_back.
4. Your application reads the JSON from file_back.

---

Result File Contract#

Production Assist writes the results to the file_back path as a single JSON object with (at least) the following top-level properties:

• Errors (object)
• Loads (array)
• Results (array)

Your application should treat the output file as the “response”.

Recommendations for robust integration:

• Wait until the output file exists and its size has stabilized before reading.
• If atomic write is not guaranteed, use a retry loop when parsing JSON.
• Implement a timeout in your application in case the desktop app is closed or fails.

---

2) PA_model glTF 2.0 Extension#

Overview#

The PA_model extension enriches glTF 2.0 assets and nodes with Production Assist structural calculation data.

• Extension name: PA_model
• Extension scope: asset and node
• GUID format: "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"

glTF Integration Notes#

A typical glTF includes:

• extensionsUsed: must include "PA_model" when present.
• extensionsRequired: include "PA_model" only if the file is meaningless without it.

Example:

{
  "asset": {
    "version": "2.0",
    "extensions": {
      "PA_model": {
        "identifier": "00000000-0000-0000-0000-000000000000",
        "layers": []
      }
    }
  },
  "extensionsUsed": ["PA_model"]
}

---

2.1 Asset Properties (asset.extensions.PA_model)#

Properties without a default value are mandatory.

Name	Type	Default	Description
identifier	string	—	GUID of the asset.
layers	array[layer]	[]	Design layers.

layer object#

Name	Type	Default	Description
identifier	string	—	GUID of the layer.
name	string	—	Human-readable name of the layer.

---

2.2 Node Properties (nodes[i].extensions.PA_model)#

Properties without a default value are mandatory.

Name	Type	Default	Description
identifier	string	—	GUID of the node.
layer_identifier	string	""	GUID of the layer associated with this node (if any).
truss	truss | null	null	Present only on nodes representing trusses.
sling	sling | null	null	Present only on nodes representing slings/hoists.

If a node represents none of these, omit both truss and sling (or set them to null).

---

2.3 Domain Objects#

Fixture object (defined for completeness)#

Name	Type	Default	Description
manufacturer	string	—	Fixture manufacturer name.
name	string	—	Fixture model name.
weight	number	0	Fixture weight.

Truss object#

Name	Type	Default	Description
manufacturer	string	—	Truss manufacturer name.
series	string	—	Truss series name.
name	string	—	Truss model name.
structure	truss_structure | null	null	Structural information.
weight	number	0	Truss weight.

Truss structure object#

Name	Type	Default	Description
center_lines	array[planar_path]	—	One or more planar paths defining truss center lines. The path normal denotes the natural upward rigging orientation.

Planar path object#

A path consisting of coplanar line segments.

Name	Type	Description
normal	number[3]	Normal vector of the plane/path.
points	array[number[3]] (min 2)	Points defining the path polyline.

Sling object#

Name	Type	Default	Description
structure	array[line] (min 1)	—	Lines defining the sling geometry.
weight	number	0	Sling weight.

Line object#

A line consisting of two points.

Name	Type	Description
points	array[2] of number[3]	Start and end point.

Panel object (defined for completeness)#

Name	Type	Default	Description
manufacturer	string	—	Panel manufacturer name.
name	string	—	Panel model name.
weight	number	0	Panel weight.

---

3) Examples#

3.1 Sling / Hoist Node Example#

{
  "name": "M1",
  "matrix": [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, -1.35057068, 5.99999952, 1.24985063, 1],
  "extensions": {
    "PA_model": {
      "identifier": "6a6dadc8-592c-4a77-8e7c-05261283ef0a",
      "layer_identifier": "6ed3ab5b-7b5e-4e65-9f8e-39b9b20b9d9c",
      "sling": {
        "structure": [
          {
            "points": [
              [0, -1.77299976, 1.1920929e-07],
              [0, 2.00000048, 0]
            ]
          }
        ],
        "weight": 0
      }
    }
  }
}

3.2 Truss Node Example#

{
  "matrix": [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, -2, 4.11349964, 1.24985075, 1],
  "extensions": {
    "PA_model": {
      "identifier": "3a38e519-ba87-49ef-af16-0c0a9d4f6e7c",
      "layer_identifier": "6ed3ab5b-7e5e-4e65-9f8e-39b9b20b9d9c",
      "truss": {
        "manufacturer": "Prolyte",
        "series": "H30V",
        "name": "H30V 2m",
        "structure": {
          "center_lines": [
            {
              "normal": [0, 1, 0],
              "points": [
                [-1, 0, 0],
                [1, 0, 0]
              ]
            }
          ]
        },
        "weight": 7.84000015
      }
    }
  }
}

---

4) Integration Checklist#

• Generate valid glTF 2.0 (.gltf or .glb)
• Add extensionsUsed: ["PA_model"]
• Populate asset.extensions.PA_model.identifier
• Populate node extensions with PA_model.identifier
• Write file to disk
• Launch productionassist://production_assist_calculate?...
• Wait for output file at file_back
• Parse JSON result (handle errors/warnings via Errors)

---

5) Output JSON Schema (file_back)#

This section documents the JSON written by Production Assist to the file_back path.

5.1 Top-level object#

Properties without a default value are mandatory.

Name	Type	Default	Description
Errors	object<string, error_item[]>	—	Map of error category key to a list of issues.
Loads	array[0..] of load_item	[]	Aggregated loads used in the calculation.
Results	array[0..] of result_item	[]	Computed results.

---

5.2 Common Types#

vec3#

A 3D vector:

Name	Type	Description
X	number	X component
Y	number	Y component
Z	number	Z component

Example:

{ "X": 0.0, "Y": 0.0, "Z": 0.0 }

quat#

A quaternion (WXYZ):

Name	Type	Description
W	number	W component
X	number	X component
Y	number	Y component
Z	number	Z component

Example:

{ "W": 1.0, "X": 0.0, "Y": 0.0, "Z": 0.0 }

---

5.3 Errors#

Errors is an object where each property name is an error category key (e.g., SUPPORT_ERROR) and the value is an array of error_item.

error_item#

Properties without a default value are mandatory.

Name	Type	Default	Description
Message	string	—	Human-readable explanation.
Error	boolean	—	true = error (typically blocks valid result), false = warning/info.
Confidence	number	1.0	Confidence level (0..1).
HasFix	boolean	false	Whether a fix action is available.
FixCommand	string	""	Fix operation identifier (if HasFix is true).
FixCommand2	string	""	Optional secondary fix operation identifier.
FixText	string	""	Optional UI text for fix action.
FixText2	string	""	Optional UI text for secondary fix action.
Object	string	—	Primary object UUID in braces, e.g. "Ellipsis".
Objects	array[0..] of string	[]	Related object UUIDs.
Position	vec3	—	Location of the issue in model coordinates.
Quat	quat	—	Orientation at the issue location.
Color	vec3	—	Display color (0..1).
DisplayFormatting	display_formatting	—	Formatting hints for overlay / annotation display.
ShowInList	boolean	true	Whether it should be shown in a UI list.
DrawHeatmap	boolean	false	Whether heatmap visualization should be enabled.
UseInAutoFix	boolean	false	Whether it can be used by an auto-fix flow.
Length	number	0.0	Associated length if applicable.
Payload	string	""	Reserved for additional data.
Payload2	string	""	Reserved for additional data.
TextStyle	string	""	Reserved for UI styling key.

display_formatting#

Properties without a default value are mandatory.

Name	Type	Default	Description
Valid	boolean	false	Whether the formatting values are valid.
TextSize	number	12	Text size in UI units.
HasLeader	boolean	false	Whether a leader line should be drawn.
HasRectangle	boolean	false	Whether a rectangle background should be drawn.
BackColor	vec3	—	Background color.
TextColor	vec3	—	Text color.
RectangleTopLeft	vec3	—	Rectangle top-left coordinate.
RectangleBottomRight	vec3	—	Rectangle bottom-right coordinate.

---

5.4 Loads#

Loads is an array of aggregated load items used as inputs to the calculation.

load_item#

Properties without a default value are mandatory.

Name	Type	Default	Description
Name	string	—	Name/label of the load item (e.g., fixture model, truss name, cable load).
Count	number	—	Quantity. For distributed loads this may reflect discretization.
DistLoad	boolean	false	true if the load is distributed.
TotalWeight	number	0	Total weight for this load item (units as configured in Production Assist).
ForceStructure	number	0	Force contribution applied to structure.
ForceSupport	number	0	Force contribution applied to supports.
LayerName	string	""	Layer name associated with the item.
LoadGroupName	string	""	Logical grouping (e.g., Cable).
Key	string	""	Reserved / grouping key.
ObjectID	string	""	Reserved / internal object id.
Set	boolean	false	Whether the load item was explicitly set/defined (true) or inferred (false).

---

5.5 Results#

Results is an array of computed results for the system and/or specific objects.

result_item#

Properties without a default value are mandatory.

Name	Type	Default	Description
Name	string	—	Display name of the result (e.g., Stiff Deflection).
Key	string	""	Result key (e.g., Stiff).
ResultType	string	—	Result kind identifier (e.g., Workload, D).
LoadCase	string	—	Load case name used for the computation.
Value	number	0	Result value.
MaxValue	number	0	Max value for scaling/visualization.
Workload	number	0	Workload value (if applicable).
NoWorkloadRed	boolean	false	UI hint controlling warning coloring.
SecondWindSpeed	boolean	false	UI/logic flag.
Angle	number	0	Angle of evaluation.
Type	number	—	Numeric type code (enum).
Unit	number	—	Numeric unit code (enum).
ObjectUuid	string	—	Target object UUID, or all-zero UUID for system-level results.
ObjectID	string	""	Reserved / internal object id.

If you maintain enum lists for Type and Unit, add them here so integrators can render values correctly.

---

5.6 Example Output#

{
  "Errors": {
    "FrameNoCrossSection": [
      {
        "Color": {
          "X": 0.31273,
          "Y": 0.32902,
          "Z": 0.0
        },
        "Confidence": 1.0,
        "DisplayFormatting": {
          "BackColor": {
            "X": 0.0,
            "Y": 0.0,
            "Z": 0.0
          },
          "HasLeader": false,
          "HasRectangle": false,
          "RectangleBottomRight": {
            "X": 0.0,
            "Y": 0.0,
            "Z": 0.0
          },
          "RectangleTopLeft": {
            "X": 0.0,
            "Y": 0.0,
            "Z": 0.0
          },
          "TextColor": {
            "X": 0.0,
            "Y": 0.0,
            "Z": 0.0
          },
          "TextSize": 12,
          "Valid": false
        },
        "DrawHeatmap": false,
        "Error": false,
        "FixCommand": "",
        "FixCommand2": "",
        "FixText": "",
        "FixText2": "",
        "HasFix": false,
        "Length": 0.0,
        "Message": "Generic has no valid Cross Section",
        "Object": "{6980F4A2-2BB5-4CEF-B4AF-755BC317A600}",
        "Objects": [
          "{E014C249-A7DD-4285-BE50-AE1F43174400}",
          "{13113FCD-8B06-417D-9391-65C76BD11300}"
        ],
        "Payload": "",
        "Payload2": "",
        "Position": {
          "X": -51.038265228271484,
          "Y": 9.781068489189302e-13,
          "Z": 4405.001640319824
        },
        "Quat": {
          "W": 1.0,
          "X": 0.0,
          "Y": 0.0,
          "Z": 0.0
        },
        "ShowInList": true,
        "TextStyle": "",
        "UseInAutoFix": false
      }
    ],
    "SUPPORT_ERROR": [
      {
        "Color": {
          "X": 0.31273,
          "Y": 0.32902,
          "Z": 0.0
        },
        "Confidence": 1.0,
        "DisplayFormatting": {
          "BackColor": {
            "X": 0.0,
            "Y": 0.0,
            "Z": 0.0
          },
          "HasLeader": false,
          "HasRectangle": false,
          "RectangleBottomRight": {
            "X": 0.0,
            "Y": 0.0,
            "Z": 0.0
          },
          "RectangleTopLeft": {
            "X": 0.0,
            "Y": 0.0,
            "Z": 0.0
          },
          "TextColor": {
            "X": 0.0,
            "Y": 0.0,
            "Z": 0.0
          },
          "TextSize": 12,
          "Valid": false
        },
        "DrawHeatmap": false,
        "Error": true,
        "FixCommand": "LR_PlaceHoistsToStructure",
        "FixCommand2": "",
        "FixText": "",
        "FixText2": "",
        "HasFix": true,
        "Length": 0.0,
        "Message": "No Supports on System",
        "Object": "{00000000-0000-0000-0000-000000000000}",
        "Objects": [
          "{6980F4A2-2BB5-4CEF-B4AF-755BC317A600}",
          "{E014C249-A7DD-4285-BE50-AE1F43174400}",
          "{13113FCD-8B06-417D-9391-65C76BD11300}"
        ],
        "Payload": "",
        "Payload2": "",
        "Position": {
          "X": -51.038265228271484,
          "Y": 9.781068489189302e-13,
          "Z": 4405.001640319824
        },
        "Quat": {
          "W": 1.0,
          "X": 0.0,
          "Y": 0.0,
          "Z": 0.0
        },
        "ShowInList": true,
        "TextStyle": "",
        "UseInAutoFix": false
      }
    ]
  },
  "Loads": [
    {
      "Count": 3.0,
      "DistLoad": false,
      "ForceStructure": 0.10790999999999999,
      "ForceSupport": 0.10790999999999999,
      "Key": "",
      "LayerName": "CP.glb",
      "LoadGroupName": "",
      "Name": "Generic Rectangular Section, 2m",
      "ObjectID": "",
      "Set": false,
      "TotalWeight": 11000.0
    },
    {
      "Count": 2.0,
      "DistLoad": false,
      "ForceStructure": 0.250155,
      "ForceSupport": 0.250155,
      "Key": "",
      "LayerName": "CP.glb",
      "LoadGroupName": "",
      "Name": "Robin MMX Spot",
      "ObjectID": "",
      "Set": false,
      "TotalWeight": 25500.0
    },
    {
      "Count": 6000.0,
      "DistLoad": true,
      "ForceStructure": 3.97305e-05,
      "ForceSupport": 2.943e-05,
      "Key": "",
      "LayerName": "",
      "LoadGroupName": "Cable",
      "Name": "Cable Load Truss",
      "ObjectID": "",
      "Set": true,
      "TotalWeight": 3.0
    }
  ],
  "Results": [
    {
      "Angle": 0.0,
      "Key": "Stiff",
      "LoadCase": "Eurocode Ultimate Failure",
      "MaxValue": 1.0,
      "Name": "Stiff Overall Workload ",
      "NoWorkloadRed": false,
      "ObjectID": "",
      "ObjectUuid": "{00000000-0000-0000-0000-000000000000}",
      "ResultType": "Workload",
      "SecondWindSpeed": false,
      "Type": 4,
      "Unit": 24,
      "Value": 0.0,
      "Workload": 0.0
    },
    {
      "Angle": 0.0,
      "Key": "Stiff",
      "LoadCase": "Eurocode Ultimate Failure",
      "MaxValue": 1000.0,
      "Name": "Stiff Deflection ",
      "NoWorkloadRed": false,
      "ObjectID": "",
      "ObjectUuid": "{00000000-0000-0000-0000-000000000000}",
      "ResultType": "D",
      "SecondWindSpeed": false,
      "Type": 4,
      "Unit": 1,
      "Value": 0.0,
      "Workload": 0.0
    }
  ]
}