rasterizePolygon (2D & 3D)

These functions generate discrete grid points that approximate the boundary and interior of a polygon in 2D or 3D space. Each function returns a unique set of integer coordinates stored in a RowVector2iSet or RowVector3iSet. Neighboring offset points are also included.

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Function Signatures

2D Version

RowVector2iSet rasterizePolygon2D(
    const Eigen::MatrixX2d& polygonVertices,
    bool needClosePolygon = true
);

• Parameters:

  • polygonVertices (Eigen::MatrixX2d): Vertices of the 2D polygon.
  • needClosePolygon (optional, bool, default = true):
    • If true, the function automatically sorts the vertices counter-clockwise and ensures the polygon is closed.
    • If false, the input vertices matrix must already be sorted and closed.

• Returns: A RowVector2iSet containing all boundary and interior grid points, plus their four corner offsets.

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3D Version

RowVector3iSet rasterizePolygon3D(
    const Eigen::MatrixX3d& polygonVertices,
    bool needClosePolygon = true
);

• Parameters:

  • polygonVertices (Eigen::MatrixX3d): Vertices of the 3D polygon.
  • needClosePolygon (optional, bool, default = true):
    • If true, the function automatically sorts the vertices counter-clockwise and ensures the polygon is closed.
    • If false, the input vertices matrix must already be sorted and closed.

• Returns: A RowVector3iSet containing all boundary and interior voxels, plus their eight surrounding offsets.

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Example Usage

#include "RasterizeTool.h"

int main() {

    Eigen::Matrix<double, 4, 3> polygonVertices;
    polygonVertices << 748694.42507040221, 2564734.3476669602, 49,
           748674.41542796092, 2564734.5007915981, 49,
           748674.4539194419, 2564739.5306861168, 81,
           748694.4635618832, 2564739.3775614789, 81;

    RowVector3iSet PointsSet = rasterizePolygon3D(polygonVertices);

    return 0;
}

The figure below shows the result of rasterizing a 3D polygon:

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