Updated the parser to work with actual NX .sim/.prt files which are binary format (not XML) in NX 12+. Key Changes: - Added dual-mode parser: XML for test files, binary for real NX files - Implemented string extraction from binary .sim files - Updated solution detection to recognize Nastran SOL types - Fixed expression extraction with proper NX format pattern: #(Type [units]) name: value; - Added multiple .prt file naming pattern support - Added .fem file parsing for FEM information Parser Capabilities: - Extracts expressions from .prt files (binary parsing) - Detects solution types (Linear Statics, Modal, etc.) - Finds element types from .fem files - Handles multiple file naming conventions Validation with Real Files: - Successfully parsed tests/Bracket_sim1.sim (6.2 MB binary file) - Extracted 1 expression: tip_thickness = 20.0 mm - Detected 18 solution types (including Nastran SOL codes) - Works with both XML test files and binary production files Technical Details: - Binary files: latin-1 decoding + regex pattern matching - Expression pattern: #(\w+\s*\[([^\]]*)\])\s*([a-zA-Z_][a-zA-Z0-9_]*)\s*:\s*([-+]?\d*\.?\d+) - Multiple .prt file search: exact match → base name → _i suffix - FEM parsing: extracts mesh, materials, element types from .fem files Next Steps: - Refine solution filtering (reduce false positives) - Add load/constraint extraction from .fem files - Test with more complex models
MCP Tools Documentation
This directory contains the MCP (Model Context Protocol) tools that enable LLM-driven optimization configuration for Atomizer.
Available Tools
1. Model Discovery (model_discovery.py) ✅ IMPLEMENTED
Purpose: Parse Siemens NX .sim files to extract FEA model information.
Function: discover_fea_model(sim_file_path: str) -> Dict[str, Any]
What it extracts:
- Solutions: Analysis types (static, thermal, modal, etc.)
- Expressions: Parametric variables that can be optimized
- FEM Info: Mesh, materials, loads, constraints
- Linked Files: Associated .prt files and result files
Usage Example:
from mcp_server.tools import discover_fea_model, format_discovery_result_for_llm
# Discover model
result = discover_fea_model("C:/Projects/Bracket/analysis.sim")
# Format for LLM
if result['status'] == 'success':
markdown_output = format_discovery_result_for_llm(result)
print(markdown_output)
# Access structured data
for expr in result['expressions']:
print(f"{expr['name']}: {expr['value']} {expr['units']}")
Command Line Usage:
python mcp_server/tools/model_discovery.py examples/test_bracket.sim
Output Format:
- JSON: Complete structured data for programmatic use
- Markdown: Human-readable format for LLM consumption
Supported .sim File Versions:
- NX 2412 (tested)
- Should work with NX 12.0+ (XML-based .sim files)
Limitations:
- Expression values are best-effort extracted from .sim XML
- For accurate values, the associated .prt file is parsed (binary parsing)
- Binary .prt parsing is heuristic-based and may miss some expressions
2. Build Optimization Config (PLANNED)
Purpose: Generate optimization_config.json from natural language requirements.
Function: build_optimization_config(requirements: str, model_info: Dict) -> Dict[str, Any]
Planned Features:
- Parse LLM instructions ("minimize stress while reducing mass")
- Select appropriate result extractors
- Suggest reasonable parameter bounds
- Generate complete config for optimization engine
3. Start Optimization (PLANNED)
Purpose: Launch optimization run with given configuration.
Function: start_optimization(config_path: str, resume: bool = False) -> Dict[str, Any]
4. Query Optimization Status (PLANNED)
Purpose: Get current status of running optimization.
Function: query_optimization_status(session_id: str) -> Dict[str, Any]
5. Extract Results (PLANNED)
Purpose: Parse FEA result files (OP2, F06, XDB) for optimization metrics.
Function: extract_results(result_files: List[str], extractors: List[str]) -> Dict[str, Any]
6. Run NX Journal (PLANNED)
Purpose: Execute NXOpen scripts via file-based communication.
Function: run_nx_journal(journal_script: str, parameters: Dict) -> Dict[str, Any]
Testing
Unit Tests
# Install pytest (if not already installed)
pip install pytest
# Run all MCP tool tests
pytest tests/mcp_server/tools/ -v
# Run specific test
pytest tests/mcp_server/tools/test_model_discovery.py -v
Example Files
Example .sim files for testing are located in examples/:
test_bracket.sim: Simple structural analysis with 4 expressions
Development Guidelines
Adding a New Tool
-
Create module:
mcp_server/tools/your_tool.py -
Implement function:
def your_tool_name(param: str) -> Dict[str, Any]:
"""
Brief description.
Args:
param: Description
Returns:
Structured result dictionary
"""
try:
# Implementation
return {
'status': 'success',
'data': result
}
except Exception as e:
return {
'status': 'error',
'error_type': 'error_category',
'message': str(e),
'suggestion': 'How to fix'
}
- Add to
__init__.py:
from .your_tool import your_tool_name
__all__ = [
# ... existing tools
"your_tool_name",
]
-
Create tests:
tests/mcp_server/tools/test_your_tool.py -
Update documentation: Add section to this README
Error Handling
All MCP tools follow a consistent error handling pattern:
Success Response:
{
"status": "success",
"data": { ... }
}
Error Response:
{
"status": "error",
"error_type": "file_not_found | invalid_file | unexpected_error",
"message": "Detailed error message",
"suggestion": "Actionable suggestion for user"
}
Integration with MCP Server
These tools are designed to be called by the MCP server and consumed by LLMs. The workflow is:
- LLM Request: "Analyze my FEA model at C:/Projects/model.sim"
- MCP Server: Calls
discover_fea_model() - Tool Returns: Structured JSON result
- MCP Server: Formats with
format_discovery_result_for_llm() - LLM Response: Uses formatted data to answer user
Future Enhancements
- Support for binary .sim file formats (older NX versions)
- Direct NXOpen integration for accurate expression extraction
- Support for additional analysis types (thermal, modal, etc.)
- Caching of parsed results for performance
- Validation of .sim file integrity
- Extraction of solver convergence settings
Last Updated: 2025-11-15 Status: Phase 1 (Model Discovery) ✅ COMPLETE