Draws sets of triangles with coordinates given by three 1-dimensional arrays in `x`, `y`, `z` and (1) a sets of `i`, `j`, `k` indices (2) Delaunay triangulation or (3) the Alpha-shape algorithm or (4) the Convex-hull algorithm

Sets the X coordinates of the vertices. The nth element of vectors `x`, `y` and `z` jointly represent the X, Y and Z coordinates of the nth vertex.

Sets the Y coordinates of the vertices. The nth element of vectors `x`, `y` and `z` jointly represent the X, Y and Z coordinates of the nth vertex.

Sets the Z coordinates of the vertices. The nth element of vectors `x`, `y` and `z` jointly represent the X, Y and Z coordinates of the nth vertex.

A vector of vertex indices, i.e. integer values between 0 and the length of the vertex vectors, representing the *first* vertex of a triangle. For example, `{i[m], j[m], k[m]}` together represent face m (triangle m) in the mesh, where `i[m] = n` points to the triplet `{x[n], y[n], z[n]}` in the vertex arrays. Therefore, each element in `i` represents a point in space, which is the first vertex of a triangle.

A vector of vertex indices, i.e. integer values between 0 and the length of the vertex vectors, representing the *second* vertex of a triangle. For example, `{i[m], j[m], k[m]}`  together represent face m (triangle m) in the mesh, where `j[m] = n` points to the triplet `{x[n], y[n], z[n]}` in the vertex arrays. Therefore, each element in `j` represents a point in space, which is the second vertex of a triangle.

A vector of vertex indices, i.e. integer values between 0 and the length of the vertex vectors, representing the *third* vertex of a triangle. For example, `{i[m], j[m], k[m]}` together represent face m (triangle m) in the mesh, where `k[m] = n` points to the triplet  `{x[n], y[n], z[n]}` in the vertex arrays. Therefore, each element in `k` represents a point in space, which is the third vertex of a triangle.

Sets the Delaunay axis, which is the axis that is perpendicular to the surface of the Delaunay triangulation. It has an effect if `i`, `j`, `k` are not provided and `alphahull` is set to indicate Delaunay triangulation.