turntable

转台式摄像机动画

让摄像机围绕产品旋转 360 度，呈现简洁的产品展示效果。从正面开始，并无缝循环。

适用场景

• 用户想制作产品转台／旋转视频
• 用户提到“绕着旋转”“环绕”“展示所有角度”“转台”
• 产品展示视频的默认首选方案

前提条件

• Blender MCP：已连接（blender-mcp 插件使用端口 9876）
• 3D 模型：已导入 Blender 场景
• 输出文件夹：~/Desktop/Blender Videos/（如有需要，请创建）
• ffmpeg：已安装，用于视频编码

参数

参数	默认值	描述
duration	5	视频时长，单位为秒
fps	24	每秒帧数
camera_distance	4.5	与物体中心的距离
camera_height	2.0	摄像机高于物体的高度
camera_lens	50	焦距，单位为 mm
transparent_bg	true	透明背景
output_format	mov	mov（带 alpha 通道的 ProRes 4444）或 webm（带 alpha 通道的 VP9）

流程

步骤 1：检测正面

从不同摄像机位置渲染 4 张低分辨率测试帧，以确定产品正面。询问用户哪一个角度是正面。

import bpy, math
from mathutils import Vector

obj = bpy.data.objects['<OBJECT_NAME>']
bbox = [obj.matrix_world @ Vector(c) for c in obj.bound_box]
center = sum(bbox, Vector()) / 8

RADIUS = 4.5
HEIGHT = 2.0

# Create temp camera
bpy.ops.object.camera_add()
cam = bpy.context.active_object
cam.name = 'TempCam'
bpy.context.scene.camera = cam

# Add track constraint to center
bpy.ops.object.empty_add(type='PLAIN_AXES', location=center)
target = bpy.context.active_object
target.name = 'TempTarget'

cam.constraints.new(type='TRACK_TO').target = target

# Render 4 angles
positions = {
    'front': (center.x, center.y - RADIUS, HEIGHT),
    'right': (center.x + RADIUS, center.y, HEIGHT),
    'back': (center.x, center.y + RADIUS, HEIGHT),
    'left': (center.x - RADIUS, center.y, HEIGHT),
}
for label, pos in positions.items():
    cam.location = pos
    bpy.context.scene.render.filepath = f'<OUTPUT>/facing_{label}.png'
    bpy.ops.render.render(write_still=True)

向用户展示全部 4 张图片，并询问哪一张是正面。

步骤 2：设置摄像机支架

import bpy, math

# Create target empty at object center
bpy.ops.object.empty_add(type='PLAIN_AXES', location=(0, 0, 0))
target = bpy.context.active_object
target.name = 'TurntableTarget'

# Create camera at front-facing position (determined from Step 1)
# Default front = -Y axis
bpy.ops.object.camera_add(location=(0, -CAMERA_DISTANCE, CAMERA_HEIGHT))
cam = bpy.context.active_object
cam.name = 'TurntableCamera'
cam.data.lens = 50

# Track to target
track = cam.constraints.new(type='TRACK_TO')
track.target = target
track.track_axis = 'TRACK_NEGATIVE_Z'
track.up_axis = 'UP_Y'

# Parent camera to target for orbit
bpy.ops.object.select_all(action='DESELECT')
cam.select_set(True)
target.select_set(True)
bpy.context.view_layer.objects.active = target
bpy.ops.object.parent_set(type='OBJECT', keep_transform=True)

bpy.context.scene.camera = cam

步骤 3：制作 360 度旋转动画

import bpy, math

TOTAL_FRAMES = DURATION * FPS  # e.g. 5 * 24 = 120

scene = bpy.context.scene
scene.frame_start = 1
scene.frame_end = TOTAL_FRAMES
scene.render.fps = FPS

target = bpy.data.objects['TurntableTarget']
target.rotation_euler = (0, 0, 0)
target.keyframe_insert(data_path='rotation_euler', frame=1)
target.rotation_euler = (0, 0, math.radians(360))
target.keyframe_insert(data_path='rotation_euler', frame=TOTAL_FRAMES + 1)

# IMPORTANT: Linear interpolation for constant speed
# Blender 5.1 uses layered actions:
action = target.animation_data.action
strip = action.layers[0].strips[0]
for cb in strip.channelbags:
    for fc in cb.fcurves:
        for kp in fc.keyframe_points:
            kp.interpolation = 'LINEAR'

步骤 4：设置灯光

import bpy, math

# Warm sunset lighting on LIGHTS only (not on materials/world)
bpy.ops.object.light_add(type='AREA', location=(3, -3, 4))
k = bpy.context.active_object; k.name='GoldenKey'
k.data.energy = 2000; k.data.size = 3.0
k.data.color = (1.0, 0.78, 0.45)
k.rotation_euler = (math.radians(45), 0, math.radians(25))

bpy.ops.object.light_add(type='AREA', location=(-3, -2, 3))
f = bpy.context.active_object; f.name='WarmFill'
f.data.energy = 1000; f.data.size = 5.0
f.data.color = (1.0, 0.75, 0.4)
f.rotation_euler = (math.radians(40), 0, math.radians(-30))

bpy.ops.object.light_add(type='AREA', location=(0, 0, 5))
oh = bpy.context.active_object; oh.name='OverheadWash'
oh.data.energy = 800; oh.data.size = 8.0
oh.data.color = (1.0, 0.92, 0.75)

bpy.ops.object.light_add(type='AREA', location=(0, 4, 2))
r = bpy.context.active_object; r.name='WarmRim'
r.data.energy = 800; r.data.size = 3.0
r.data.color = (1.0, 0.65, 0.3)
r.rotation_euler = (math.radians(-40), 0, math.radians(180))

bpy.ops.object.light_add(type='AREA', location=(4, 0, 0.5))
sw = bpy.context.active_object; sw.name='SideGlow'
sw.data.energy = 600; sw.data.size = 2.0
sw.data.color = (1.0, 0.8, 0.5)
sw.rotation_euler = (math.radians(5), 0, math.radians(90))

步骤 5：渲染

import bpy, os

scene = bpy.context.scene
scene.render.resolution_x = 1920
scene.render.resolution_y = 1080
scene.render.film_transparent = True
scene.render.engine = 'CYCLES'  # better metallic reflections
scene.cycles.samples = 64
scene.cycles.use_denoising = True
scene.cycles.device = 'GPU'
scene.render.image_settings.file_format = 'PNG'
scene.render.image_settings.color_mode = 'RGBA'

# Neutral world for subtle reflections (not colored)
if not scene.world:
    scene.world = bpy.data.worlds.new("World")
scene.world.use_nodes = True
bg = scene.world.node_tree.nodes.get('Background')
bg.inputs['Color'].default_value = (0.95, 0.95, 0.95, 1)
bg.inputs['Strength'].default_value = 0.3

frames_dir = os.path.expanduser('~/Desktop/Blender Videos/turntable_frames/')
os.makedirs(frames_dir, exist_ok=True)
scene.render.filepath = frames_dir

bpy.ops.render.render(animation=True)

步骤 6：编码视频

渲染期间 MCP 会超时。轮询帧目录，直到所有帧都生成后再进行编码：

# ProRes 4444 with alpha (transparent)
ffmpeg -y -framerate 24 \
  -i "~/Desktop/Blender Videos/turntable_frames/%04d.png" \
  -c:v prores_ks -profile:v 4444 -pix_fmt yuva444p10le \
  "~/Desktop/Blender Videos/turntable.mov"

Blender 5.1 说明

• 渲染引擎枚举值：BLENDER_EEVEE（而非 BLENDER_EEVEE_NEXT）
• 没有 FFMPEG 输出格式 — 渲染 PNG 序列，再使用 ffmpeg 编码
• 分层动作 API：使用 action.layers[0].strips[0].channelbags 访问 fcurves
• 设置 film_transparent = True 可使用透明背景
• 暖色应设置在灯光上，而不是世界／材质上