blender-compositing

Blender Compositing Skill

Version: 3.0.0 Last Updated: 2026-06-15 Dependencies: Blender 5.1+

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Breaking Changes (5.1+)

Compositor Node Tree Access Changed

scene.node_tree no longer exists. Use scene.compositing_node_group instead. Must create the node group manually if None.

import bpy

scene = bpy.context.scene
scene.use_nodes = True

# [FAIL] BROKEN in 5.1+
# compositor = scene.node_tree

# [OK] Access or create compositor node group
comp_tree = scene.compositing_node_group
if comp_tree is None:
    comp_tree = bpy.data.node_groups.new(name="Compositor", type='CompositorNodeTree')
    scene.compositing_node_group = comp_tree

scene.render.use_compositing = True

CompositorNodeComposite Removed

There is no Composite output node in 5.1+. The main render output comes directly from the render pipeline (set via scene.render.filepath and scene.render.image_settings). Use CompositorNodeViewer for preview and CompositorNodeOutputFile for additional outputs.

import bpy

# [FAIL] BROKEN in 5.1+ (RuntimeError: Node type undefined)
# composite = nodes.new('CompositorNodeComposite')

# [OK] Main render output is controlled by scene.render settings
scene = bpy.context.scene
scene.render.filepath = "//output/render_"
scene.render.image_settings.file_format = 'PNG'

# [OK] Use Viewer for compositor preview
viewer = comp_tree.nodes.new('CompositorNodeViewer')

CompositorNodeMapRange Removed

No Map Range node in the compositor. Use ShaderNodeMath (works in compositor context) to build equivalent logic.

import bpy

# [FAIL] BROKEN in 5.1+
# map_range = comp_tree.nodes.new('CompositorNodeMapRange')

# [OK] Use Math nodes for range mapping
# Example: clamp depth to max 80m, then normalize
clamp = comp_tree.nodes.new('ShaderNodeMath')
clamp.operation = 'MINIMUM'
clamp.inputs[1].default_value = 80.0

normalize = comp_tree.nodes.new('CompositorNodeNormalize')
comp_tree.links.new(rl.outputs['Depth'], clamp.inputs[0])
comp_tree.links.new(clamp.outputs[0], normalize.inputs[0])