JRRF2026に向けたMakerChip製作記

import bpy
import math
import bmesh

def create_heavy_thread_manifold_coin_case():
    for name in ["CoinCase_Base", "CoinCase_Lid"]:
        if name in bpy.data.objects:
            bpy.data.objects.remove(bpy.data.objects[name], do_unlink=True)
        if name + "_Mesh" in bpy.data.meshes:
            bpy.data.meshes.remove(bpy.data.meshes[name + "_Mesh"])

    N = 128
    Z_TOP = 3.5
    Z_FLOOR = 0.6
    Z_NECK = 2.9
    Z_LID_CAVITY = 3.0

    R_OUTER = 20.0
    R_INNER = 16.0

    R_BASE_ROOT = 17.2
    THREAD_DEPTH = 0.65
    THREAD_H_WIDTH = 0.65
    CLEARANCE = 0.15

    R_LID_ROOT = R_BASE_ROOT + THREAD_DEPTH + CLEARANCE
    
    LEAD = 3.0
    PITCH = LEAD / 2
    Z_START = 0.8

    def clip(z, z_min, z_max):
        return max(z_min, min(z_max, z))

    def get_screw_params(t):
        zc1 = Z_START + LEAD * t
        if 0.05 <= t <= 0.45:
            tl = (t - 0.05) / 0.40
            f = (tl / 0.2) if tl < 0.2 else (((1.0 - tl) / 0.2) if tl > 0.8 else 1.0)
            d1 = THREAD_DEPTH * f
        else:
            d1 = 0.0

        zc2 = zc1 - PITCH
        if 0.55 <= t <= 0.95:
            tl = (t - 0.55) / 0.40
            f = (tl / 0.2) if tl < 0.2 else (((1.0 - tl) / 0.2) if tl > 0.8 else 1.0)
            d2 = THREAD_DEPTH * f
        else:
            d2 = 0.0

        return zc1, d1, zc2, d2

    def get_base_profile(t):
        zc1, d1, zc2, d2 = get_screw_params(t)

        z2_b = clip(zc2 - THREAD_H_WIDTH, Z_FLOOR, Z_NECK)
        z2_m = clip(zc2, Z_FLOOR, Z_NECK)
        z2_t = clip(zc2 + THREAD_H_WIDTH, Z_FLOOR, Z_NECK)

        z1_b = clip(zc1 - THREAD_H_WIDTH, Z_FLOOR, Z_NECK)
        z1_m = clip(zc1, Z_FLOOR, Z_NECK)
        z1_t = clip(zc1 + THREAD_H_WIDTH, Z_FLOOR, Z_NECK)

        return [
            (0.0, 0.0), (R_OUTER, 0.0), (R_OUTER, Z_FLOOR), (R_BASE_ROOT, Z_FLOOR),
            (R_BASE_ROOT, z2_b), (R_BASE_ROOT + d2, z2_m), (R_BASE_ROOT, z2_t),
            (R_BASE_ROOT, z1_b), (R_BASE_ROOT + d1, z1_m), (R_BASE_ROOT, z1_t),
            (R_BASE_ROOT, Z_NECK), (R_INNER, Z_NECK), (R_INNER, Z_FLOOR), (0.0, Z_FLOOR)
        ]

    def get_lid_profile(t):
        zc1, d1, zc2, d2 = get_screw_params(t)

        z2_b = clip(zc2 - THREAD_H_WIDTH, Z_FLOOR, Z_LID_CAVITY)
        z2_m = clip(zc2, Z_FLOOR, Z_LID_CAVITY)
        z2_t = clip(zc2 + THREAD_H_WIDTH, Z_FLOOR, Z_LID_CAVITY)

        z1_b = clip(zc1 - THREAD_H_WIDTH, Z_FLOOR, Z_LID_CAVITY)
        z1_m = clip(zc1, Z_FLOOR, Z_LID_CAVITY)
        z1_t = clip(zc1 + THREAD_H_WIDTH, Z_FLOOR, Z_LID_CAVITY)

        return [
            (0.0, Z_TOP), (R_OUTER, Z_TOP), (R_OUTER, Z_FLOOR), (R_LID_ROOT, Z_FLOOR),
            (R_LID_ROOT, z2_b), (R_LID_ROOT - d2, z2_m), (R_LID_ROOT, z2_t),
            (R_LID_ROOT, z1_b), (R_LID_ROOT - d1, z1_m), (R_LID_ROOT, z1_t),
            (R_LID_ROOT, Z_LID_CAVITY), (0.0, Z_LID_CAVITY)
        ]

    def build_mesh(name, profile_func):
        verts = []
        faces = []
        num_u = len(profile_func(0.0))

        for i in range(N):
            t = i / N
            angle = 2 * math.pi * t
            prof = profile_func(t)
            for r, z in prof:
                verts.append((r * math.cos(angle), r * math.sin(angle), z))

        for i in range(N):
            next_i = (i + 1) % N
            for j in range(num_u - 1):
                v0 = i * num_u + j
                v1 = i * num_u + (j + 1)
                v2 = next_i * num_u + (j + 1)
                v3 = next_i * num_u + j
                faces.append((v0, v1, v2, v3))

        mesh = bpy.data.meshes.new(name + "_Mesh")
        mesh.from_pydata(verts, [], faces)
        mesh.update()

        bm = bmesh.new()
        bm.from_mesh(mesh)
        bmesh.ops.remove_doubles(bm, verts=bm.verts, dist=0.001)
        bmesh.ops.recalc_face_normals(bm, faces=bm.faces)
        bm.to_mesh(mesh)
        bm.free()

        obj = bpy.data.objects.new(name, mesh)
        bpy.context.collection.objects.link(obj)
        return obj

    base_obj = build_mesh("CoinCase_Base", get_base_profile)
    lid_obj = build_mesh("CoinCase_Lid", get_lid_profile)

    base_obj.location.x = -22.0
    lid_obj.location.x = 22.0
    lid_obj.rotation_euler[1] = math.pi
    lid_obj.location.z = Z_TOP

create_heavy_thread_manifold_coin_case()