Denoising uses image processing to reduce speckled noise left by low sample counts. It can soften fine detail, so tune it together with the sample count.
Also known as: DenoisingDenoisescene.cycles.use_denoising
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bpy — this entry
# 거친 금속 머리와 색 조각의 간접광을 낮은 샘플로 그려 디노이즈 전후를 비교한다.
reset('CYCLES', samples=8)
camera((5, -8, 4.5), target=(0, 0, 1), lens=58)
floor()
hdri('studio', strength=0.32)
studio(key=650, fill=160, rim=360)
bpy.ops.mesh.primitive_monkey_add(location=(0, 0, 1.05))
head = bpy.context.object
paint(head, material('Brushed metal', CORAL, roughness=0.16, metallic=0.75))
beads = []
for x, color in [(-1.8, SKY), (1.8, LIME)]:
bpy.ops.mesh.primitive_uv_sphere_add(segments=32, ring_count=16, radius=0.48, location=(x, 0.6, 0.5))
bead = bpy.context.object
bpy.ops.object.shade_smooth()
paint(bead, material('Color bead', color, roughness=0.24, metallic=0.15))
beads.append(bead)
frame(head, *beads, margin=1.25)
sc = bpy.context.scene
sc.cycles.seed = 23
sc.cycles.samples = 8
sc.cycles.use_denoising = False
shoot('raw')
sc.cycles.use_denoising = True
shoot('denoised')
Full script — runs as-is in Blender 5.1.1
# denoise — Blender 5.1.1 에서 그대로 돌아가는 스크립트
# 실행: blender -b --factory-startup --python denoise.py -- <출력 폴더>
SLUG = 'denoise'
# ── 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 ──
# 거친 금속 머리와 색 조각의 간접광을 낮은 샘플로 그려 디노이즈 전후를 비교한다.
reset('CYCLES', samples=8)
camera((5, -8, 4.5), target=(0, 0, 1), lens=58)
floor()
hdri('studio', strength=0.32)
studio(key=650, fill=160, rim=360)
bpy.ops.mesh.primitive_monkey_add(location=(0, 0, 1.05))
head = bpy.context.object
paint(head, material('Brushed metal', CORAL, roughness=0.16, metallic=0.75))
beads = []
for x, color in [(-1.8, SKY), (1.8, LIME)]:
bpy.ops.mesh.primitive_uv_sphere_add(segments=32, ring_count=16, radius=0.48, location=(x, 0.6, 0.5))
bead = bpy.context.object
bpy.ops.object.shade_smooth()
paint(bead, material('Color bead', color, roughness=0.24, metallic=0.15))
beads.append(bead)
frame(head, *beads, margin=1.25)
sc = bpy.context.scene
sc.cycles.seed = 23
sc.cycles.samples = 8
sc.cycles.use_denoising = False
shoot('raw')
sc.cycles.use_denoising = True
shoot('denoised')
Small highlights scattered across a metal Suzanne lit by indirect light make denoising easy to see: it uses neighboring color and shape to smooth noise. Turn on Denoise under Render Properties ▸ Sampling in Cycles to reduce noise after rendering.
In Python, set scene.cycles.use_denoising = True. This example compares the same 8-sample render of a metallic head and colored props with denoising off and on. For more control, use a Denoise node in the Compositor; that workflow also needs the relevant input passes.
Denoising does not replace sample calculation. With too few samples, it can leave blotches or smear reflections instead of clean detail. Raise samples first when fine metal texture or thin edges matter, then check that the denoised result still preserves them.
When to use
Use it to reduce fine noise while keeping render times down. Compare the original and denoised image where detail matters.
