File size: 4,041 Bytes
6de1b61 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | from __future__ import annotations
from dataclasses import dataclass
from .models import Design
def clamp(value: float, low: float, high: float) -> float:
return max(low, min(high, value))
@dataclass
class Mesh:
nodes: list[dict]
tets: list[list[int]]
length: float
width: float
height: float
def point_in_feature_volume(point: dict, design: Design) -> bool:
x, y, z = point["x"], point["y"], point["z"]
length = design.base_length_mm
half_width = design.base_width_mm / 2
thickness = design.base_thickness_mm
solid = 0 <= x <= length and -half_width <= y <= half_width and 0 <= z <= thickness
if solid and z <= thickness:
for hole in design.fixed_holes:
if ((x - hole.x) ** 2 + (y - hole.y) ** 2) ** 0.5 < hole.radius:
solid = False
for feature in design.features:
if feature.type == "lightening_hole" and ((x - feature.x) ** 2 + (y - feature.y) ** 2) ** 0.5 < feature.radius:
solid = False
for feature in design.features:
if feature.type == "boss":
radius = clamp(feature.radius, 1, 20)
height = clamp(feature.height, 1, 40)
if ((x - feature.x) ** 2 + (y - feature.y) ** 2) ** 0.5 <= radius and thickness <= z <= thickness + height:
solid = True
if feature.type == "rib":
ax, ay, bx, by = feature.x, feature.y, feature.x2, feature.y2
vx, vy = bx - ax, by - ay
length_sq = max(vx * vx + vy * vy, 1)
t = clamp(((x - ax) * vx + (y - ay) * vy) / length_sq, 0, 1)
px, py = ax + t * vx, ay + t * vy
rib_height = clamp(feature.height, 1, 60)
if ((x - px) ** 2 + (y - py) ** 2) ** 0.5 <= max(feature.width, 1) / 2 and thickness <= z <= thickness + rib_height:
solid = True
return solid
def build_structured_tet_mesh(design: Design, nx: int = 7, ny: int = 5, nz: int = 5) -> Mesh:
length = clamp(design.base_length_mm, 30, 240)
width = clamp(design.base_width_mm, 10, 120)
thickness = clamp(design.base_thickness_mm, 1, 30)
max_feature_height = max(
[feature.height for feature in design.features if feature.type in {"rib", "boss"}] or [0]
)
height = max(thickness + max_feature_height, thickness * 2)
nodes: list[dict] = []
node_id: dict[tuple[int, int, int], int] = {}
tets: list[list[int]] = []
def grid_point(i: int, j: int, k: int) -> dict:
return {
"x": length * i / nx,
"y": -width / 2 + width * j / ny,
"z": height * k / nz,
}
def add_node(i: int, j: int, k: int) -> int:
key = (i, j, k)
if key in node_id:
return node_id[key]
idx = len(nodes)
nodes.append({"id": idx, **grid_point(i, j, k)})
node_id[key] = idx
return idx
tet_pattern = [
[0, 1, 3, 7],
[0, 3, 2, 7],
[0, 2, 6, 7],
[0, 6, 4, 7],
[0, 4, 5, 7],
[0, 5, 1, 7],
]
for i in range(nx):
for j in range(ny):
for k in range(nz):
p0 = grid_point(i, j, k)
p1 = grid_point(i + 1, j + 1, k + 1)
center = {"x": (p0["x"] + p1["x"]) / 2, "y": (p0["y"] + p1["y"]) / 2, "z": (p0["z"] + p1["z"]) / 2}
if not point_in_feature_volume(center, design):
continue
corners = [
add_node(i, j, k),
add_node(i + 1, j, k),
add_node(i, j + 1, k),
add_node(i + 1, j + 1, k),
add_node(i, j, k + 1),
add_node(i + 1, j, k + 1),
add_node(i, j + 1, k + 1),
add_node(i + 1, j + 1, k + 1),
]
for tet in tet_pattern:
tets.append([corners[idx] for idx in tet])
return Mesh(nodes=nodes, tets=tets, length=length, width=width, height=height)
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