openscad/BOSL2
1
0
Fork 0
mirror of https://github.com/revarbat/BOSL2.git synced 2025-08-28 23:09:50 +02:00
Code Issues Projects Releases Wiki Activity

Removed VNF construction from octa spheroids.

Browse Source
This commit is contained in:
Revar Desmera
2025-08-25 05:22:16 -07:00
parent dfe5baf230
commit e1002748d3
1 changed files with 92 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

112
shapes3d.scad
View File

@@ -3370,14 +3370,20 @@ function _make_octa_sphere(r) =
edge2 = zrot(90, p=edge1),
edge3 = xrot(-90, p=edge1),
// Function to calculate greater arc point between two points
greater_arc_point = function(p1, p2, u)
let(
vec = vector_axis(p1, p2),
ang = vector_angle(p1, p2),
subang = lerp(0, ang, u),
pt = rot(a=subang, v=vec, p=p1)
) pt,
// Precache edge points, axes, and angles
edge_pts1 = [for (i = [0:1:subdivs]) [edge1[i], edge2[i]]],
edge_pts2 = [for (i = [0:1:subdivs]) [edge1[subdivs-i], edge3[subdivs-i]]],
edge_pts3 = [for (i = [0:1:subdivs]) [edge2[subdivs-i], edge3[i]]],
// Precache greater circle axes
edge_axis1 = [UP, for (i = [1:1:subdivs]) vector_axis(edge_pts1[i][0], edge_pts1[i][1])],
edge_axis2 = [UP, for (i = [1:1:subdivs]) vector_axis(edge_pts2[i][0], edge_pts2[i][1])],
edge_axis3 = [UP, for (i = [1:1:subdivs]) vector_axis(edge_pts3[i][0], edge_pts3[i][1])],
// Precache greater circle angles
edge_ang1 = [0, for (i = [1:1:subdivs]) vector_angle(edge_pts1[i][0], edge_pts1[i][1])],
edge_ang2 = [0, for (i = [1:1:subdivs]) vector_angle(edge_pts2[i][0], edge_pts2[i][1])],
edge_ang3 = [0, for (i = [1:1:subdivs]) vector_angle(edge_pts3[i][0], edge_pts3[i][1])],
// Calculate greater circle subdivisions between octant edges to get vertices.
pts = [
@@ -3391,26 +3397,90 @@ function _make_octa_sphere(r) =
edge3[subdivs-col] // Point on third edge is exact. (± FP rounding)
else // Calculating interior point.
let(
p1 = greater_arc_point(edge1[row], edge2[row], col/row),
p2 = greater_arc_point(edge1[row-col], edge3[row-col], col/(subdivs-row+col)),
p3 = greater_arc_point(edge2[col], edge3[subdivs-col], (row-col)/(subdivs-col))
i1 = row,
i2 = subdivs - row + col,
i3 = subdivs - col,
u1 = col / i1,
u2 = col / i2,
u3 = (row - col) / i3,
p1 = rot(a=lerp(0, edge_ang1[i1], u1), v=edge_axis1[i1], p=edge_pts1[i1][0]),
p2 = rot(a=lerp(0, edge_ang2[i2], u2), v=edge_axis2[i2], p=edge_pts2[i2][0]),
p3 = rot(a=lerp(0, edge_ang3[i3], u3), v=edge_axis3[i3], p=edge_pts3[i3][0])
) unit(p1 + p2 + p3) * r // Average greater circle points beween the three edge pairs.
]
],
// Calculate the triangulations of the averaged octant vertices.
octant_vnf = vnf_tri_array(pts),
rows = [
[ pts[0][0] ],
// Make 4 rotated copies of the octant to get the top of the sphere.
top_vnf = vnf_join([
for (row = [1:1:subdivs]) [
for (a = [0:90:359])
zrot(a, p=octant_vnf)
]),
each zrot(a, p=select(pts[row], [0:1:row-1]))
],
// Copy the top, flipped on the Z axis to get the bottom, and put them together into one VNF.
bot_vnf = zflip(p=top_vnf),
full_vnf = vnf_join([top_vnf, bot_vnf])
) full_vnf;
for (row = [subdivs-1:-1:1]) [
for (a = [0:90:359])
each zrot(a, p=zflip(p=select(pts[row], [0:1:row-1])))
],
[ zflip(p=pts[0][0]) ]
],
verts = flatten(rows),
offsets = cumsum([0, for (row = rows) len(row)]),
faces = [
for (i = [0:1:3])
let(
l1 = len(rows[1]),
o1 = offsets[1]
)
[i+o1, 0, (i+1)%l1+o1],
for (j = [1:1:subdivs-1])
let(
l1 = len(rows[j]),
l2 = len(rows[j+1]),
o1 = offsets[j],
o2 = offsets[j+1],
q1 = len(rows[j])/4,
q2 = len(rows[j+1])/4
)
for (n = [0:1:3])
each [
[o2+q2*n, o1+q1*n, o2+(q2*n+1)%l2],
for (i = [0:1:q1-1]) each [
[o2+(i+q2*n+1)%l2, o1+(i+q1*n+1)%l1, o2+(i+q2*n+2)%l2],
[o2+(i+q2*n+1)%l2, o1+(i+q1*n)%l1, o1+(i+q1*n+1)%l1]
]
],
for (j = [subdivs:1:2*subdivs-2])
let(
l1 = len(rows[j]),
l2 = len(rows[j+1]),
o1 = offsets[j],
o2 = offsets[j+1],
q1 = len(rows[j])/4,
q2 = len(rows[j+1])/4
)
for (n = [0:1:3])
each [
[o2+q2*n, o1+q1*n, o1+(q1*n+1)%l1],
for (i = [0:1:q1-2]) each [
[o2+(i+q2*n)%l2, o1+(i+q1*n+1)%l1, o2+(i+q2*n+1)%l2],
[o1+(i+q1*n+2)%l1, o2+(i+q2*n+1)%l2, o1+(i+q1*n+1)%l1]
]
],
for (i = [0:1:3])
let(
row = len(rows) -2,
l1 = len(rows[row]),
o1 = offsets[row],
o2 = offsets[row+1]
)
[o2, o1+i, o1+(i+1)%l1]
]
) [verts, faces];
function spheroid(r, style="aligned", d, circum=false, anchor=CENTER, spin=0, orient=UP) =