Our Solution
A library of functions that meet the requirements for Modeling a Surface.

Tools and Technologies

• Development tools: Visual Studio with C++.
• Operating System: Microsoft Windows NT
• Repository: Visual SourceSafe

Methodology
ESN has a well-defined Software Development Life Cycle (SDLC) model that takes an iterative approach in executing a project. Each build or milestone would have incremental functionality. Builds/milestones are scheduled so that obtaining specific requirements related to the build/milestone, revision of project documents, planning, thorough testing and bug fixing are carried out incrementally.

This approach mitigates risks in Project implementation.

One of the team members plays the role of a Quality Analyst. The main activities of a Quality Analyst are to review and update project documents, organize testing activities and conduct regular code reviews and code walkthroughs.

Designated Team Members work along with the Quality Analyst as members of the testing team continuously aiming to enhance the quality of the software delivered.

Benefits
The advantage of this library is that it can be used in a variety of applications such as plug-ins to packages like AutoCAD and other software that has Surface Modeling requirements.

Introduction

The library is about the creation of a surface, 2-dimensional and 3-dimensional, through a triangulated irregular network (TIN) using a set of points representing the geographic locations.

Features

The library has the following features:

General

• Process the data collected from digital data station, process them to get a codified data file (ASCII or binary) and process them to get a TIN.
• Represent the breaklines, ridges, boundaries, islands, etc., efficiently.
• Process data of the order of 100,000 points in the least time possible.
• Merging of different surfaces, calculation of cut and fill volumes

Building

• Build a surface from a list of points with/without breaklines ignoring the duplicate points.
• Build a surface from a given list of contours (contour data in the form of points)

Editing

• Insertion/Deletion of a point inside/outside the surface with a given coordinate. The TIN is dynamically updated
• Insertion of breakline with a given set of vertices
• Deletion of a triangulated line given its vertices. This updates the TIN dynamically
• Flip the face of a triangulated line given the vertices of the line.

Advanced

• Make a hole in a surface given a boundary of points
• Merge two surfaces
• Creation of ponds given a tri-dimensional boundary.

Miscellaneous

• Find the height of a point inside the surface given its coordinates
• Read/write the surface information from/to a binary/ASCII file.

Our Process

We created the following while working on this library:

• Created a requirements specification. Revised the document based on reviews.
• Preparation of the High-level document describing the functional flow of the library of functions to be used.
• Preparation of the Detailed Design giving the details of the function prototypes, pseudocode etc.
• Implementing the library
• Initial testing of the implemented functionality
• Fixing the bugs that were identified.

Conclusion

A library of functions for creating the surface from a set of geographical points obtained through digital stations was written. This project is a case study of our expertise in the development of triangulated irregular networks and surface modeling.