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Fixed broken line-plane intersections. Attachment enhanced vnf_polyhedron().

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This commit is contained in:
Garth Minette
2020-08-28 19:07:10 -07:00
parent 7051f8ef19
commit e1b0985afc
5 changed files with 49 additions and 19 deletions
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26
geometry.scad
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@@ -1007,11 +1007,20 @@ function closest_point_on_plane(plane, point) =
// Returns [LINE, undef] if the line is on the plane.
// Returns undef if line is parallel to, but not on the given plane.
function _general_plane_line_intersection(plane, line, eps=EPSILON) =
let( a = plane*[each line[0],-1],
b = plane*[each(line[1]-line[0]),-1] )
approx(b,0,eps)
? points_on_plane(line[0],plane,eps)? [line,undef]: undef
: [ line[0]+a/b*(line[1]-line[0]), a/b ];
let(
l0 = line[0], // Ray start point
u = line[1] - l0, // Ray direction vector
n = plane_normal(plane),
p0 = n * plane[3], // A point on the plane
w = l0 - p0 // Vector from plane point to ray start
) approx(n*u, 0, eps=eps) ? (
// Line is parallel to plane.
approx(n*w, 0, eps=eps)
? [line, undef] // Line is on the plane.
: undef // Line never intersects the plane.
) : let(
t = (-n * w) / (n * u) // Distance ratio along ray
) [ l0 + u*t, t ];
// Function: plane_line_angle()
@@ -1098,8 +1107,8 @@ function polygon_line_intersection(poly, line, bounded=false, eps=EPSILON) =
linevec = unit(line[1] - line[0]),
lp1 = line[0] + (bounded[0]? 0 : -1000000) * linevec,
lp2 = line[1] + (bounded[1]? 0 : 1000000) * linevec,
poly2d = clockwise_polygon(project_plane(poly, p1, p2, p3)),
line2d = project_plane([lp1,lp2], p1, p2, p3),
poly2d = clockwise_polygon(project_plane(poly, plane)),
line2d = project_plane([lp1,lp2], plane),
parts = split_path_at_region_crossings(line2d, [poly2d], closed=false),
inside = [for (part = parts)
if (point_in_polygon(mean(part), poly2d)>0) part
@@ -1107,7 +1116,7 @@ function polygon_line_intersection(poly, line, bounded=false, eps=EPSILON) =
)
!inside? undef :
let(
isegs = [for (seg = inside) lift_plane(seg, p1, p2, p3) ]
isegs = [for (seg = inside) lift_plane(seg, plane) ]
)
isegs
)
@@ -1264,7 +1273,6 @@ function find_circle_2tangents(pt1, pt2, pt3, r, d, tangents=false) =
x = hyp * cos(a/2),
tp1 = pt2 + x * v1,
tp2 = pt2 + x * v2,
// fff=echo(tp1=tp1,cp=cp,pt2=pt2),
dang1 = vector_angle(tp1-cp,pt2-cp),
dang2 = vector_angle(tp2-cp,pt2-cp)
)