# IK influence 0·1에서 평가된 본 위치를 렌더용 막대로 그려 비교한다.
reset('WORKBENCH')
camera((2.0, -6.0, 8.8), target=(0.5, 0, 1.7), lens=52)
floor()
data = bpy.data.armatures.new('IK Armature')
rig = bpy.data.objects.new('IK Armature', data)
bpy.context.scene.collection.objects.link(rig)
bpy.context.view_layer.objects.active = rig
rig.select_set(True)
bpy.ops.object.mode_set(mode='EDIT')
previous = None
for name, head, tail in [
('upper', (0, 0, 0.35), (0, 0, 1.35)),
('lower', (0, 0, 1.35), (0, 0, 2.35)),
('hand', (0, 0, 2.35), (0, 0, 3.25)),
]:
bone = data.edit_bones.new(name)
bone.head, bone.tail = head, tail
bone.parent = previous
bone.use_connect = previous is not None
previous = bone
bpy.ops.object.mode_set(mode='OBJECT')
rig.show_in_front = True
target = bpy.data.objects.new('IK target', None)
bpy.context.scene.collection.objects.link(target)
target.location = (1.45, 0, 1.85)
target.empty_display_type = 'SPHERE'
target.empty_display_size = 0.18
bpy.ops.mesh.primitive_uv_sphere_add(segments=20, ring_count=12, radius=0.18, location=target.location)
goal = bpy.context.object
goal.name = 'Target marker'
paint(goal, material('Target', LIME))
constraint = rig.pose.bones['hand'].constraints.new('IK')
constraint.target = target
constraint.chain_count = 3
constraint.use_tail = True
constraint.influence = 0.0
rods = {}
for name, color in [('upper', CLAY), ('lower', SKY), ('hand', CORAL)]:
bpy.ops.mesh.primitive_cylinder_add(vertices=20, radius=0.14, depth=1)
rod = bpy.context.object
rod.name = name + ' · render proxy'
paint(rod, material(name, color))
rods[name] = rod
def sync_chain():
bpy.context.view_layer.update()
evaluated = rig.evaluated_get(bpy.context.evaluated_depsgraph_get())
for name, rod in rods.items():
bone = evaluated.pose.bones[name]
head = evaluated.matrix_world @ bone.matrix.translation
tail = evaluated.matrix_world @ (bone.matrix @ Vector((0, bone.length, 0)))
direction = tail - head
rod.location = (head + tail) * 0.5
rod.rotation_mode = 'QUATERNION'
rod.rotation_quaternion = direction.to_track_quat('Z', 'Y')
rod.scale.z = direction.length
sync_chain()
frame(*rods.values(), goal, margin=1.45)
shoot('free')
constraint.influence = 1.0
sync_chain()
shoot('reach')전체 스크립트 — Blender 5.1.1 에서 그대로 실행 복사 # inverse-kinematics — Blender 5.1.1 에서 그대로 돌아가는 스크립트
# 실행: blender -b --factory-startup --python inverse-kinematics.py -- <출력 폴더>
SLUG = 'inverse-kinematics'
# ── 무대: 모든 항목이 같이 쓰는 준비 코드 (renders/_stage.py) ──────────────────
# 빈 장면 → 렌더 엔진·크기 → 카메라·바닥·조명·재질 도우미 → shoot() 으로 WebP 저장.
import bpy, math, os, sys
from mathutils import Vector
# 출력 폴더: blender -b --factory-startup --python 이파일.py -- <출력 폴더>
OUT = sys.argv[sys.argv.index('--') + 1] if '--' in sys.argv[:-1] else os.getcwd()
os.makedirs(OUT, exist_ok=True)
# 색은 화면에서 고르는 sRGB 0~1 값으로 적는다. 블렌더 내부는 선형(linear)이라 srgb() 로 바꿔 넣는다.
BACKDROP = (0.24, 0.25, 0.27)
CLAY = (0.80, 0.77, 0.72)
LIME = (0.64, 0.90, 0.21)
SKY = (0.22, 0.65, 0.95)
CORAL = (0.96, 0.42, 0.45)
INK = (0.08, 0.09, 0.10)
ENGINES = {'WORKBENCH': 'BLENDER_WORKBENCH', 'EEVEE': 'BLENDER_EEVEE', 'CYCLES': 'CYCLES'}
def srgb(c, alpha=1.0):
lin = lambda v: v / 12.92 if v <= 0.04045 else ((v + 0.055) / 1.055) ** 2.4
return (lin(c[0]), lin(c[1]), lin(c[2]), alpha)
def reset(engine='WORKBENCH', samples=16, size=(960, 600)):
"""빈 장면에서 시작한다. engine: WORKBENCH(모양 확인) · EEVEE(실시간) · CYCLES(경로 추적)."""
bpy.ops.wm.read_factory_settings(use_empty=True)
sc = bpy.context.scene
sc.render.engine = ENGINES[engine]
sc.render.resolution_x, sc.render.resolution_y = size
sc.render.resolution_percentage = 100
sc.render.image_settings.file_format = 'WEBP'
sc.render.image_settings.quality = 82
sc.world = bpy.data.worlds.new('World')
world_color(BACKDROP)
if engine == 'WORKBENCH':
sh = sc.display.shading
sh.light, sh.color_type = 'STUDIO', 'MATERIAL'
sh.show_shadows, sh.shadow_intensity = True, 0.35
sh.show_cavity = True
sc.display.render_aa = '16'
sc.view_settings.view_transform = 'Standard' # 재질 색을 그대로 보여 준다
elif engine == 'EEVEE':
sc.eevee.taa_render_samples = samples
else:
sc.cycles.samples = samples
sc.cycles.use_denoising = True
return sc
def world_color(color, strength=1.0):
"""배경색. Workbench 는 world.color, EEVEE·Cycles 는 Background 노드를 쓴다."""
w = bpy.context.scene.world
w.color = srgb(color)[:3]
bg = w.node_tree.nodes.get('Background') if w.node_tree else None
if bg:
bg.inputs['Color'].default_value = srgb(color)
bg.inputs['Strength'].default_value = strength
return w
def hdri(name='studio', strength=1.0, show=False):
"""블렌더에 들어 있는 HDRI 로 장면을 비춘다(CC0 · Poly Haven). name: studio · city · courtyard · forest · interior · night · sunrise · sunset.
show=False 면 빛과 반사에만 쓰고, 카메라에는 BACKDROP 색 배경이 보인다(Light Path 의 Is Camera Ray 로 가른다)."""
nt = bpy.context.scene.world.node_tree
nodes, links = nt.nodes, nt.links
env = nodes.new('ShaderNodeTexEnvironment')
env.image = bpy.data.images.load(os.path.join(bpy.utils.system_resource('DATAFILES'), 'studiolights', 'world', f'{name}.exr'))
bg = nodes['Background']
bg.inputs['Strength'].default_value = strength
links.new(env.outputs['Color'], bg.inputs['Color'])
if not show:
flat = nodes.new('ShaderNodeBackground')
flat.inputs['Color'].default_value = srgb(BACKDROP)
ray, mix = nodes.new('ShaderNodeLightPath'), nodes.new('ShaderNodeMixShader')
links.new(ray.outputs['Is Camera Ray'], mix.inputs['Fac'])
links.new(bg.outputs['Background'], mix.inputs[1])
links.new(flat.outputs['Background'], mix.inputs[2])
links.new(mix.outputs['Shader'], nodes['World Output'].inputs['Surface'])
return env
def look_at(obj, target):
obj.rotation_euler = (Vector(target) - obj.location).to_track_quat('-Z', 'Y').to_euler()
def camera(location=(7, -7, 5), target=(0, 0, 0.5), lens=50):
cam = bpy.data.objects.new('Camera', bpy.data.cameras.new('Camera'))
bpy.context.scene.collection.objects.link(cam)
cam.location = location
look_at(cam, target)
cam.data.lens = lens
bpy.context.scene.camera = cam
return cam
def frame(*objs, margin=1.15):
"""카메라 방향은 그대로 두고, objs 가 화면에 다 들어오게 카메라를 앞뒤로 옮긴다."""
sc = bpy.context.scene
dg = bpy.context.evaluated_depsgraph_get()
pts = [o.matrix_world @ Vector(c) for o in objs for c in o.evaluated_get(dg).bound_box]
mid = sum(pts, Vector()) / len(pts)
coords = [c for p in pts for c in (mid + (p - mid) * margin)]
loc, _scale = sc.camera.camera_fit_coords(dg, coords)
sc.camera.location = loc
return sc.camera
def light(kind='AREA', location=(4, -4, 6), target=(0, 0, 0), energy=600, size=3.0, color=(1, 1, 1)):
"""kind: POINT · SUN · SPOT · AREA. energy 는 와트(SUN 은 W/m²에 해당하는 세기)."""
data = bpy.data.lights.new(kind.title(), kind)
data.energy, data.color = energy, color
if kind == 'AREA':
data.size = size
obj = bpy.data.objects.new(data.name, data)
bpy.context.scene.collection.objects.link(obj)
obj.location = location
look_at(obj, target)
return obj
def studio(key=700, fill=200, rim=450):
"""기본 3점 조명(키·필·림). EEVEE·Cycles 용 — Workbench 는 자체 스튜디오 조명을 쓴다."""
return [light('AREA', (5, -4, 6), energy=key, size=4),
light('AREA', (-6, -3, 3), energy=fill, size=5),
light('AREA', (0, 6, 5), energy=rim, size=3)]
def material(name, color=CLAY, roughness=0.5, metallic=0.0, **inputs):
"""원리 BSDF 재질. inputs 는 소켓 이름(공백은 _ 로): Emission_Strength=3."""
mat = bpy.data.materials.new(name)
mat.diffuse_color = srgb(color) # Workbench 가 보는 색
bsdf = mat.node_tree.nodes['Principled BSDF']
bsdf.inputs['Base Color'].default_value = srgb(color)
bsdf.inputs['Roughness'].default_value = roughness
bsdf.inputs['Metallic'].default_value = metallic
for key, value in inputs.items():
bsdf.inputs[key.replace('_', ' ')].default_value = value
return mat
def paint(obj, mat):
obj.data.materials.clear()
obj.data.materials.append(mat)
return obj
def floor(size=80.0, color=None, z=0.0, wall=30.0, curve=6.0):
"""바닥과 뒷벽(+Y 쪽)이 둥글게 이어진 스튜디오 배경 — 지평선이 보이지 않는다. 카메라는 -Y 쪽에서 +Y 를 보게 둔다."""
import bmesh
back = size / 2
steps = 12
profile = [(-back, 0.0)] # (y, z) 단면: 앞 → 둥근 모서리 → 벽 위
for i in range(steps + 1):
a = (math.pi / 2) * i / steps
profile.append((back - curve + curve * math.sin(a), curve - curve * math.cos(a)))
profile.append((back, wall))
bm = bmesh.new()
left = [bm.verts.new((-back, y, z + h)) for y, h in profile]
right = [bm.verts.new((back, y, z + h)) for y, h in profile]
for i in range(len(profile) - 1):
bm.faces.new((left[i], right[i], right[i + 1], left[i + 1]))
me = bpy.data.meshes.new('Floor')
bm.to_mesh(me)
bm.free()
obj = bpy.data.objects.new('Floor', me)
bpy.context.scene.collection.objects.link(obj)
for poly in me.polygons:
poly.use_smooth = True
return paint(obj, material('Floor', color or BACKDROP, roughness=0.9))
def edges(obj, thickness=0.012, color=INK):
"""메시의 선(엣지)을 렌더에 보이게 한다 — 모디파이어까지 적용된 모양에 와이어프레임을 씌운 복제본."""
dg = bpy.context.evaluated_depsgraph_get()
wire = bpy.data.objects.new(obj.name + '.edges', bpy.data.meshes.new_from_object(obj.evaluated_get(dg)))
bpy.context.scene.collection.objects.link(wire)
wire.matrix_world = obj.matrix_world.copy()
mod = wire.modifiers.new('Wireframe', 'WIREFRAME')
mod.thickness, mod.use_even_offset = thickness, True
return paint(wire, material(obj.name + '.edges', color, roughness=0.8))
def shoot(name):
"""지금 장면을 <출력 폴더>/<항목>-<name>.webp 로 렌더한다."""
sc = bpy.context.scene
sc.render.filepath = os.path.join(OUT, f'{SLUG}-{name}.webp')
bpy.ops.render.render(write_still=True)
return sc.render.filepath
# ── 이 항목 ──
# IK influence 0·1에서 평가된 본 위치를 렌더용 막대로 그려 비교한다.
reset('WORKBENCH')
camera((2.0, -6.0, 8.8), target=(0.5, 0, 1.7), lens=52)
floor()
data = bpy.data.armatures.new('IK Armature')
rig = bpy.data.objects.new('IK Armature', data)
bpy.context.scene.collection.objects.link(rig)
bpy.context.view_layer.objects.active = rig
rig.select_set(True)
bpy.ops.object.mode_set(mode='EDIT')
previous = None
for name, head, tail in [
('upper', (0, 0, 0.35), (0, 0, 1.35)),
('lower', (0, 0, 1.35), (0, 0, 2.35)),
('hand', (0, 0, 2.35), (0, 0, 3.25)),
]:
bone = data.edit_bones.new(name)
bone.head, bone.tail = head, tail
bone.parent = previous
bone.use_connect = previous is not None
previous = bone
bpy.ops.object.mode_set(mode='OBJECT')
rig.show_in_front = True
target = bpy.data.objects.new('IK target', None)
bpy.context.scene.collection.objects.link(target)
target.location = (1.45, 0, 1.85)
target.empty_display_type = 'SPHERE'
target.empty_display_size = 0.18
bpy.ops.mesh.primitive_uv_sphere_add(segments=20, ring_count=12, radius=0.18, location=target.location)
goal = bpy.context.object
goal.name = 'Target marker'
paint(goal, material('Target', LIME))
constraint = rig.pose.bones['hand'].constraints.new('IK')
constraint.target = target
constraint.chain_count = 3
constraint.use_tail = True
constraint.influence = 0.0
rods = {}
for name, color in [('upper', CLAY), ('lower', SKY), ('hand', CORAL)]:
bpy.ops.mesh.primitive_cylinder_add(vertices=20, radius=0.14, depth=1)
rod = bpy.context.object
rod.name = name + ' · render proxy'
paint(rod, material(name, color))
rods[name] = rod
def sync_chain():
bpy.context.view_layer.update()
evaluated = rig.evaluated_get(bpy.context.evaluated_depsgraph_get())
for name, rod in rods.items():
bone = evaluated.pose.bones[name]
head = evaluated.matrix_world @ bone.matrix.translation
tail = evaluated.matrix_world @ (bone.matrix @ Vector((0, bone.length, 0)))
direction = tail - head
rod.location = (head + tail) * 0.5
rod.rotation_mode = 'QUATERNION'
rod.rotation_quaternion = direction.to_track_quat('Z', 'Y')
rod.scale.z = direction.length
sync_chain()
frame(*rods.values(), goal, margin=1.45)
shoot('free')
constraint.influence = 1.0
sync_chain()
shoot('reach')