BSpline Curves 3D

Rendering 3D B-splines using OpenGL, Qt, C++ and Eigen.

B-splines are parameterics curves which consists of several Bezier curves whose control points satisfy some special conditions. I used cubic Bezier curves for the interpolation of knots. Given a set of knots, a cubic Bezier is generated between each knot. Then these Bezier curves are glued together and forming the final curve, B-spline. The algorithm for the generation of the curves can be found here. Although it is about 2D B-splines, interpolating 3D B-splines is not so different. I implemented the algorithm in CreateCoefficientMatrix, GetSplineControlPoints and Update methods of Spline class.

For the rendering algorithm, this resource helped me a lot. The vertex generation algorithm can be found in PipeDumb.geom shader or in GenerateVertices method of Bezier class.

Build

1. Install CMake 3.25.1 or above.
2. Install Visual Studio 2022 and MSVC C++ v143 Compiler.
3. Install Qt 6.x.y MSVC2019 64bit kit.
4. Set environment variable Qt6_DIR as C:\Qt\6.x.y\msvc2019_64.
5. Clone the repo git clone https://github.com/berkbavas/BSplineCurves3D.git.
6. Create a folder mkdir Build.
7. Enter the folder cd Build.
8. Run CMake cmake ...
9. Open BSplineCurves3D.sln with Visual Studio 2022.
10. Build & Run with Release configuration.

Screenshots

UML Diagram

Keywords

C++, Qt 6, OpenGL, GLSL, Curves, Bezier Curves, 3D B-Spline, Eigen, Curve rendering