geometry
layer¶
The geometry
layer has the following geometry primitives, each stored in a
separate dataset:
Dataset name | Vertices | Edges | Faces | Dimensions |
---|---|---|---|---|
lines |
2 | 1 | 0 | 1 |
triangles |
3 | 3 | 1 | 2 |
quads |
4 | 4 | 1 | 2 |
hexagons |
6 | 6 | 1 | 2 |
tetrahedrons |
4 | 6 | 4 | 3 |
cuboids |
8 | 12 | 6 | 3 |
A vertex is a point in 3D space whose coordinates are defined as a (x, y,
z)
triplet, while a single coordinate is represented by a floating point
number.
Each dataset stores a single geometry primitive per row, and has 3 times as many columns as its corresponding geometry primitive has vertices. This is because only the coordinates are stored, and each vertex is defined by 3 coordinates.
For example, the quads
dataset requires 12 columns to store its
coordinates, as it has 4 vertices. A single row of this dataset would be layed
out like so:
# Vertex "A" Vertex "B" Vertex "C" Vertex "D"
# x y z x y z x y z x y z
1.1 1.2 1.3 2.1 2.2 2.3 3.1 3.2 3.3 4.1 4.2 4.3
Each dataset also has the following attributes attached to it:
num_vertices
- Number of vertices, stored as an integer number.
num_coordinates
Number of coordinates, stored as an integer number.
Equal to:
num_vertices * 3