orient_by_vectors: Orient 3D data by vectors

In cornelmpop/Lithics3D: A toolbox for 3D analysis of archaeological lithics

Orient 3D data by vectors

Description

Rotates the input 3D data using two vectors, such that the first vector is aligned with the X axis (i.e. y,z=0 at both endpoints), with the starting point at the origin, and the second vector is on a plane that is parallel to the XY plane, with the starting point having a lower y value than the endpoint.

Usage

orient_by_vectors(l1, l2, coords, e_coords = NULL)

Arguments

l1	A 2x3 matrix-like object with coordinates defining a line, one per row.
l2	A 2x3 matrix-like object with coordinates defining a line, one per row.
coords	A Nx3 matrix-like object containing xyz point coordinates, one per row. Normally these would be mesh vertices, obtained with t(mesh$vb)[, 1:3]
e_coords	An optional Nx3 matrix-like object containing xyz point coordinates, one per row, for additional coordinates which should be kept separately (e.g. landmarks, or the input vectors).

Value

A list containing rotated input coordinates (coords and e_coords)

Note

This function will orient objects consistently in 3D. In other words, if landmarks are placed in the same order at homologous points, the oriented object will be facing the same direction not only on the XY plane, but also along the Z axis (i.e. the dorsal of flakes will always point in the same direction)

Author(s)

Cornel M. Pop

See Also

rotate_v2v()

Examples

data(demoFlake2)
len <- demoFlake2$lms[c(3,nrow(demoFlake2$lms)), ] # Tip to pt. percussion
pw <- demoFlake2$lms[c(1,nrow(demoFlake2$lms) - 1), ] # Platform width vec
res <- orient_by_vectors(len, pw, t(demoFlake2$mesh$vb)[, 1:3], rbind(len, pw))
## Not run: 
view3d(theta=0, phi=0)
axes3d(labels=T)
res.mesh = list(vb=t(cbind(res$coords, 1)), it=demoFlake2$mesh$it)
class(res.mesh) <- "mesh3d"
shade3d(res.mesh, col="green", alpha=0.4)
points3d(res$e_coords[c(1,1), ], col="red", size=15)
points3d(res$e_coords[c(2,2), ], col="red", size=10)
points3d(res$e_coords[c(3,3), ], col="purple", size=15)
points3d(res$e_coords[c(4,4), ], col="orange", size=10)

## End(Not run)

cornelmpop/Lithics3D documentation built on Feb. 10, 2024, 11:54 p.m.