blender-rendering

Need photoreal? Caustics? Accurate SSS? Glass-rich?
├── YES → Cycles (path tracer)
└── NO  → Need speed? Stylized look? Animation iteration?
          ├── YES → EEVEE
          └── NO  → Cycles (default fallback for photoreal)

import bpy

scene = bpy.context.scene
scene.render.engine = 'CYCLES'
scene.cycles.device = 'GPU'

# Sampling
scene.cycles.samples = 256
scene.cycles.use_adaptive_sampling = True
scene.cycles.adaptive_threshold = 0.01
scene.cycles.adaptive_min_samples = 32

# Denoising (recommended)
scene.cycles.use_denoising = True
scene.cycles.denoiser = 'OPENIMAGEDENOISE'   # safe default; switch to 'OPTIX' on NVIDIA RTX

# Light paths (defaults are reasonable; bump transmission for glass-rich scenes)
scene.cycles.max_bounces = 12
scene.cycles.transmission_bounces = 12

# Resolution
scene.render.resolution_x = 1920
scene.render.resolution_y = 1080
scene.render.resolution_percentage = 100

print('render:cycles_production_preset')

import bpy

scene = bpy.context.scene
scene.render.engine = 'CYCLES'
scene.cycles.device = 'GPU'
scene.cycles.samples = 64
scene.cycles.use_adaptive_sampling = True
scene.cycles.adaptive_threshold = 0.05
scene.cycles.use_denoising = True
scene.render.resolution_percentage = 50    # half res for tests
print('render:cycles_draft')

import bpy

scene = bpy.context.scene

# Engine name changed across versions:
#   Blender ≤ 4.1:        'BLENDER_EEVEE'
#   Blender 4.2 only:     'BLENDER_EEVEE_NEXT' (transitional; replaced)
#   Blender ≥ 5.0:        'BLENDER_EEVEE' (the new EEVEE replaced the old)
# Try the new name first; fall back if it doesn't exist on this Blender.
try:
    scene.render.engine = 'BLENDER_EEVEE_NEXT'
except (TypeError, ValueError):
    scene.render.engine = 'BLENDER_EEVEE'

# Preserve older EEVEE options only where the installed API exposes them.
settings = dict(taa_render_samples=64, taa_samples=16, use_gtao=True,
                gtao_distance=0.2, use_bloom=True, use_ssr=True,
                use_ssr_refraction=True, use_volumetric_lights=True)
eevee = getattr(scene, 'eevee', None)
unavailable = []
for name, value in settings.items():
    if eevee is not None and hasattr(eevee, name):
        setattr(eevee, name, value)
    else:
        unavailable.append(name)
if (eevee is not None and not hasattr(eevee, 'use_gtao')
        and all(hasattr(eevee, n) for n in ('use_fast_gi', 'fast_gi_method', 'fast_gi_distance'))
        and 'AMBIENT_OCCLUSION_ONLY' in
        {item.identifier for item in eevee.bl_rna.properties['fast_gi_method'].enum_items}):
    eevee.use_fast_gi = True
    eevee.fast_gi_method = 'AMBIENT_OCCLUSION_ONLY'
    eevee.fast_gi_distance = 0.2
    unavailable = [n for n in unavailable if n not in ('use_gtao', 'gtao_distance')]
scene.render.resolution_x = 1920
scene.render.resolution_y = 1080
print(f'render:eevee_preset unavailable_legacy_options:{unavailable}')

import bpy

scene = bpy.context.scene

# View transform — controls the "look" mapping HDR → display
scene.view_settings.view_transform = 'AgX'         # default Blender 4.x; replaces Filmic
scene.view_settings.look = 'AgX - Medium High Contrast'

# Or: 'Filmic' (older but still supported), 'Standard' (oversaturates highlights)

scene.view_settings.exposure = 0.0
scene.view_settings.gamma = 1.0
print('render:colormanagement_AgX')

import bpy

scene = bpy.context.scene

# Camera guard — required before every render
def ensure_camera(scene):
    if scene.camera is not None:
        return scene.camera.name
    cams = [o for o in bpy.data.objects if o.type == 'CAMERA']
    if not cams:
        raise RuntimeError("No camera in scene — add one before rendering")
    scene.camera = cams[0]
    return cams[0].name

cam_name = ensure_camera(scene)
print(f"camera:{cam_name}")

scene.render.image_settings.file_format = 'PNG'
scene.render.image_settings.color_mode = 'RGBA'
scene.render.image_settings.color_depth = '16'    # 16-bit for compositing later
scene.render.filepath = '/tmp/output_hero.png'

bpy.ops.render.render(write_still=True)
print(f"render:saved {scene.render.filepath}")

import bpy

scene = bpy.context.scene

# Camera guard — same pattern as Recipe 5
def ensure_camera(scene):
    if scene.camera is not None:
        return scene.camera.name
    cams = [o for o in bpy.data.objects if o.type == 'CAMERA']
    if not cams:
        raise RuntimeError("No camera in scene — add one before rendering")
    scene.camera = cams[0]
    return cams[0].name

cam_name = ensure_camera(scene)
print(f"camera:{cam_name}")

scene.frame_start = 1
scene.frame_end = 240
scene.render.fps = 24

scene.render.image_settings.file_format = 'PNG'
scene.render.filepath = '/tmp/anim/frame_'   # output: frame_0001.png, frame_0002.png, ...

# Resilience: keep partial work on crash
scene.render.use_placeholder = True
scene.render.use_overwrite = False

# Reuse mesh data between frames (faster)
scene.render.use_persistent_data = True

bpy.ops.render.render(animation=True)
print('render:animation_done')

ffmpeg -framerate 24 -i frame_%04d.png -c:v libx264 -pix_fmt yuv420p -crf 18 anim.mp4

import bpy

scene = bpy.context.scene

# 1. Cap subdivision in render
scene.render.use_simplify = True
scene.render.simplify_subdivision = 1
scene.render.simplify_subdivision_render = 2

# 2. Higher noise threshold (faster, more denoiser-dependent)
scene.cycles.adaptive_threshold = 0.05

# 3. Lower light path bounces (lose some realism)
scene.cycles.max_bounces = 8
scene.cycles.diffuse_bounces = 3
scene.cycles.glossy_bounces = 3
print('render:performance_tuned')

import bpy

prefs = bpy.context.preferences.addons['cycles'].preferences
prefs.compute_device_type = 'OPTIX'   # or 'CUDA', 'HIP' (AMD), 'METAL' (Mac)
for device in prefs.devices:
    device.use = True
print(f"gpu:{prefs.compute_device_type} devices:{len(prefs.devices)}")