A precise TIN clipping algorithm for the digital mining design of the opencast coal mine

Area of Science:

• Geographic Information Systems (GIS)
• Computational Geometry
• Mining Engineering

Background:

• Digital elevation models (DEMs) are crucial for opencast coal mine design.
• Triangulated Irregular Networks (TINs) are commonly used to represent DEMs in mining.
• Existing TIN clipping algorithms can be inefficient and may lose local details.

Purpose of the Study:

• To develop a precise and efficient TIN clipping algorithm for opencast coal mine digital design.
• To improve the efficiency of TIN clipping by utilizing spatial indexing.
• To ensure the preservation of local details during the clipping process.

Main Methods:

• A spatial grid index is employed to efficiently embed the clipping polygon (CP) into the clipped TIN (CTIN).
• CP vertex elevations are interpolated, and intersections between the CP and CTIN are calculated.
• A constrained Delaunay triangulation (CDT) growth algorithm is used to generate a new boundary TIN, followed by topology modification for separation.

Main Results:

• The algorithm successfully clips TIN data, accurately representing the boundaries defined by the clipping polygon.
• The use of a spatial grid index significantly improves the efficiency of the clipping process.
• Local details within the TIN are preserved after clipping, ensuring data integrity.

Conclusions:

• The developed TIN clipping algorithm is robust and highly efficient for opencast coal mine digital design.
• The algorithm's ability to maintain local details makes it suitable for practical mining applications.
• Implementation in C# and .NET facilitates its integration into existing digital mining software.