Blender 3.5.0

What's new in this version:

Animation & Rigging:
General:
- The old (pre-3.0) pose library has been removed
- Fixed an old bug where the effect of the Invert Vertex Group toggle of the Armature modifier was inverted when Multi-Modifier was active. Old tutorials explaining the usage of the Multi-Modifier option will need updating
- Added the pin icon to the Dope Sheet to pin channels
- Added "Select Linked Vertices" to weight paint mode
- Take subframes into account when jumping to next/previous keyframes
- Motion paths have a new frame range option "Manual Range" to ensure the frame range is never changed on update
- Adding F-Curve modifiers to multiple channels at once is now easier to access

Asset Browser and Pose Library:
- The Pose Library went through a few usability changes to unify the experience of the other asset types
- The Pose Library functionality in the asset browser were moved to a new Asset menu, as well as the pose asset context menu.

In the viewport, a few options were removed:
- The option to Create Pose Assets is no longer there - use instead the Action Editor or the Asset Browser.
- The Flip Pose check-box is gone - flipped poses can be applied directly via the context menu. When blending, keep CTRL pressed to blend the flipped pose.
- The poselib.apply_pose_asset_for_keymap and poselib.blend_pose_asset_for_keymap operators are gone. If you have assigned these in your keymap, use the regular apply/blend operators (poselib.blend_pose_asset and poselib.apply_pose_asset) instead.

Other improvements are:
- A pose asset can now be "subtracted" while blending. Drag to the right to blend as usual, drag to the left to subtract the pose
- While blending, keep Ctrl pressed to flip the pose
- Blending can now also exaggerate a pose, by pressing E (for Extrapolate) and applying a pose for more than 100%

Graph Editor:
Ease Operator:
- The Graph Editor got a new Operator, "Ease" (76a68649c1c1), that can align keys on an exponential curve. This is useful for quickly making an easing transition on multiple keys. It can be found under Key » Slider Operators.

Pose Mode:
Propagate Pose:
- The Propagate Pose Operator has been updated (200a114e1596). Previously it used to evaluate each FCurve individually to find the target key. That resulted in undesired behavior when the keys where not on the same frame. Now it finds the frame first by checking all FCurves in question and then propagates the pose to it. It will add a keyframe to it in case it doesn't exist.

Core:
Custom Properties:
- Custom properties can now have a boolean type

Datablocks:
- 'Fake User' on linked data will now always enforce that linked data-block to be considered as 'directly linked', i.e. never automatically cleared by Blender on file save. See #105786 and 133dde41bb for details.

EEVEE & Viewport:
Viewport Compositor:
- A new Viewport Compositor shading option was added that applies the result of the Compositor Editor node-tree directly in the 3D Viewport. This feature is a work in progress and not all compositor setups are supported. Refer to #99210 for the status of the project.

Metal Viewport:
- When running on a MacOS device Blender will now use the Metal back-end for the user interface and 3D viewport. Metal provides improved performance, better stability and on par compatibility compared with other platforms.
- Improved performance affects rendering as well as animation playback

Grease Pencil:
Operators:
- Sculpt Auto-masking moved to Global setting
- Added new Auto-masking pie menu using Shift+Alt+A
- Interpolate Sequence by default can now use all different keyframes types as extremes and a new option Exclude Breakdowns was added to allows users exclude this type of keyframes from the interpolation as with the old behavior
- Interpolate Sequence by default can now use all different keyframes types as extremes and a new option Exclude Breakdowns was added to allows users exclude this type of keyframes from the interpolation as with the old behavior
- Copy & Paste now works in multiframe mode

UI:
- Vertex Opacity parameter now is visible in Overlay panel in Sculpt mode
- Radial control now displays the correct size when resizing brush size
- Create new layer using Y menu in Drawing mode allows to enter new layer name
- Material popover now display Fill color for Fill materials

Modifiers:
- Add offset (Location, Rotation, Scale) by Layer, Stroke and Material to the Offset Modifier
- New Natural Drawing Speed mode in Build Modifier timing property that replay drawings using the recorded speed of the stylus, giving it a more natural feel

Modeling:
- A new Set Attribute operator allows basic control over generic attribute values in edit mode
- A new Flip Quad Tessellation operator allows control over the tessellation orientation of quads
- Edit mesh conversion to evaluated meshes has been parallelized and can be over twice as fast depending on the mesh and CPU
- UV Editing
- Copy/Paste
- The most anticipated UV feature in this release is UV Copy and UV Paste.
- For low poly modeling and game assets, you can now select connected faces, select from the menu "UV > Copy UVs", this will make a copy of the UVs in a separate clipboard.
- Next, select different faces that have the same topology. They can be on a different mesh, a different UV channel, or even a different .blend file. Choose "Paste UVs", and the UVs will be pasted over

Improvements:
- The Constrain to Image Bounds feature received fixes for the Shear Operator, and to improve robustness on unusual inputs. With this change, all of the UV operators should now correctly support Constrain to Image Bounds and it can now be considered feature complete
- UV Sphere Projection and UV Cylinder Projection now have better handling of UVs at the poles. In addition, you can now specify whether to "Fan" or "Pinch" the UVs. All the projection options are now fully supported in all modes

Fixes:
- Bring back the missing UV overlay in Texture Paint Mode
- Select Similar now has support for Similar Object and Similar Winding
- Fix UV Unwrap for quads with Reflex Angles
- Fix UV Unwrap broken for n-gons with 3 shared vertices

Nodes & Physics:
Geometry Nodes:
General:
- A new Image Info node allows retrieving various information about an image
- There is a new Image input node
- The Named Attribute input node now has an "Exists" output to tell whether the attribute exists
- A new Blur Attribute nodes allows mixing attribute values of neighboring elements
- The Store Named Attribute node can now store 2D vector attributes
- The Image Texture node has a new mirror extension type
- Field utility nodes have been renamed
- Interpolate Domain -> Evaluate on Domain
- Field at Index -> Evaluate at Index
- The modifier user interface has been improved in various ways
- Exposed properties from node groups no longer have hard min and max values
- Checkboxes are used for exposed boolean sockets
- The "Use Attribute" toggles have moved to the right edge of the panel
- Drag and drop is supported for geometry node group assets in the viewport (bfa7f9db0e797a1).
- A new operator "Move to Nodes" creates a new node group wrapping the modifier's group (5ca65001ea9e90c).

Curves:
- New Interpolate Curves node allows generating child curves between a set of guides
- The Trim Curves node now has a selection input
- Making simple procedural changes can be much faster in some cases, and non-topology changing sculpt brushes are slightly faster

Mesh:
- The new Edges to Face Groups node finds groups of faces surrounded by selected edges (50dfd5f501d3e07)
- The mesh primitive nodes now output a UV map (previously that was stored as named attribute with a hard-coded name
- The Split Edges node is over two times faster
- For mesh objects, applying modifier will now give an error message if the geometry it creates doesn't contain a mesh

Instances:
- Caching of geometry bounds can make viewport display of many geometry instances 2-3x faster

Node Editor:
User Interface:
- The context menu has been significantly improved, giving quick access to more features
- Automatically attaching nodes after adding or moving them can be disabled by holding Alt
- For Copy & Paste, nodes are placed at the mouse position rather than their original locations
- The Geometry Nodes add menu is reorganized to make it easier to explorer
- Node links can be swapped between sockets by holding Alt while connecting them This replaces the auto-swapping behavior

Cloth Simulation:
- Self-collision was optimized with a 25% overall fps gain on some collision-heavy tests

Pipeline, Assets & I/O:
USD:
- Support for import and export of USDZ (compressed version of USD) was added
- USD export changes to pass usdchecker
- Add scale and bias for exported USD Preview Surface normal maps
- Convert USD camera properties to mm from USD units
- Support importing USD Shapes
- Author extents on exported UsdGeomMesh

OBJ:
- New OBJ importer got "Split by Objects" and "Split by Groups" import settings, just like the old Python based addon had
- New OBJ importer can now import polylines with more than 2 vertices
- Removing incorrect edge recalculation made the OBJ exporter up to 1.6x faster

Assets:
- New "All" asset library (35e54b52e6). Displays contents from all other asset libraries. This asset library is shown in Asset Browsers by default (7ba59c8a62).
- New "Essentials" asset library (b3fb73f325) containing a number of assets that are now shipped with Blender. It includes a number of hair node groups for use with geometry nodes.
- The user interface for setting up asset libraries in the Preferences has been revamped
- A default import method (Append, Append
- Import Type has been renamed to Import Method

glTF 2.0:
- Find the changelog in the Add-ons section

Python API:
Breaking changes:
BGL Deprecation:
- BGL is a direct wrapper around OpenGL calls. The BGL module is deprecated for and since Blender 3.4 has been replaced with the gpu module. From this release it will not work when using the Metal backend. Add-ons and scripts that uses the bgl module are warned about the deprecation and should use the gpu module in stead.
- Class Registration
- Registering classes with the names matching existing built-in types now raises an error

Node Group Sockets:
- Virtual sockets are the extra sockets added to group input and output nodes. Previously connecting a link to them would create an input or output in the corresponding node group. That feature was meant as a UI/UX feature though, and is now implemented differently in Blender and doesn't happen automatically. The correct way to add a group input from Python is to use node_tree.inputs.new(...).
- Grease Pencil
- Auto-masking settings were moved from brush to tool settings, for details see 4c182aef7ce0.

Motion Tracking:
- The internal storage of the optical center (principal point) has been changed in 7dea18b3aa to a normalized space.
- The normalized space refers to coordinate (0, 0) corresponding to the frame center, (-1, -1) the left bottom frame corner, (1, 1) is the top right frame corner. This notation is available via clip.tracking.camera.principal_point property.
- For some algorithms it is convenient to operate in the pixel space. For those usecases the new clip.tracking.camera.principal_point_pixels property has been added
- The old clip.tracking.camera.principal has been removed to avoid ambiguous naming in the API

Armature Modifier:
- An old bug where the effect of the Invert Vertex Group toggle of the Armature modifier was inverted when Multi-Modifier was active was fixed

- Scripts creating complex armature modifier setups need updating to check the exact blender version:
- modifier.use_multi_modifier = True
if bpy.app.version_file < (3, 5, 8): # Blender bug T103074
- modifier.invert_vertex_group = True

Data Transer:
- For bpy.ops.object.datalayout_transfer operator, VCOL has been split into COLOR_VERTEX and COLOR_CORNER for different color domains (93d84e87b26c, eae36be372a6).

Internal Mesh Format:
- The mesh data structure refactoring from earlier releases has continued in 3.5. See the similar section in the 3.4 release notes.
- The active and default (for render) color attributes are now stored as strings, making it easier to change them and access the correct attributes
- Mesh vertex positions are now accessible via the builtin position attribute
- UV layers are now stored as generic 2D vector attributes on the face corner domain
- The MeshUVLoop Python type is deprecated and will be removed in 4.0. Its data collection member is also deprecated, replaced with separate collection members named uv, vertex_selection, edge_selection, and pin. Accessing the data member is emulated for backwards compatibility for now, but the emulation comes with a performance penalty
- The sharp edge property is now stored as a generic attribute, accessible with the sharp_edge name
- Loose edge status is stored separately internally
- The MeshEdge.is_loose property is no longer editable.
- Loose edge status can be recalculated with Mesh.update(calc_edges_loose=True)
- Data access is generally faster than before when accessed with the attribute API (i.e. `mesh.attributes["sharp_edge"]), but slightly slower than before when accessed with the old properties.

Bundled Libraries:
- Python bindings for the following libraries are now bundled with Blender, and available to use by add-ons.
- USD
- OpenVDB
- OpenImageIO
- OpenColorIO
- MaterialX

Other Changes:
- The users site-packages are now available by default without having to use --python-use-system-env (72c012ab4a3d2a7)
- New ModifierData.execution_time property that can be used for profiling and optimization. It's not exposed in the UI yet (8adebaeb7c3c663).
- New object.modifiers.move() method for reordering modifiers without using operators
- The active catalog of Asset Browsers can be changed via bpy.types.FileAssetSelectParams.catalog_id, it's no longer read-only
- Custom node tree now have a default name set to NodeTree.bl_label

Cycles:
Light Sampling:
- Cycles now uses a light tree to more effectively sample scenes with many lights. This can significantly reduce noise, at the cost of a somewhat longer render time per sample.
- Light tree sampling is enabled by default in new scenes. It can be disabled in the Sampling > Lights panel.
- If the light tree yields different render results, the most likely cause is light clamping. Clamping is a biased method that depends on the sampling strategy. Generally if the light tree works well, there will be less clamping and the render will be closer to the unbiased result.
- The light tree works best in scenes with physically correct lighting, that is no custom falloff or ray visibility tricks. These may interfere with heuristics used in the light tree.
- Materials with emission now have a new Emission Sampling setting, replacing the previous Multiple Importance Sample toggle. Auto is the new default, and uses a heuristic to estimate the emitted light intensity to determine of the mesh should be considered as a light for sampling. For single sided emitters or closed meshes, setting this to Front faces only can reduce noise with the light tree.
- The light tree is currently disabled for AMD GPUs on Windows, Linux and macOS. We hope to resolve this in the next release.

Open Shading Language:
- OSL can now be used with OptiX on the GPU, in addition to existing support with CPU rendering.
- There are some limitations currently, in particular for image texture, AO and bevel nodes. See the OSL documentation for details.

Apple Metal:
- GPU rendering performance on Apple devices was improved, without various incremental changes and tunings

The big change is kernel specialization for shaders. This works transparently: rendering starts quickly with a generic shader and optimized shaders are compiled in the background and used when ready. This optimization can be configured in the preferences.

Changes:
- Improved adaptive sampling for overexposed scenes, reducing render time by taking into account absolute light intensity
- This can negatively affect some scenes where compositing or color management are used to make the scene much darker or lighter. For best results adjust the Film > Exposure setting to bring the intensity into a good range, and then do further compositing and color management on top of that. Note that this setting is not the same as Color Management > Exposure.
- Spot lights support for non-uniform object scale
- Area lights with ellipse shape and spread have much reduced noise
- Fix Anisotropic BSDF with Beckmann roughness using isotropic sampling

Sculpt, Paint, Texture:
New Features:
- Support for Vector Displacement Map (VDM) brushes for the Draw brush
- Added Extrude Mode for Trim tools. See manual for Box Trim, Lasso Trim

User Manual:
- Visit the user manual at blender.org/manual
- The user manual got a major rewrite of many pages
- Individual tool pages were rewritten and restructured
- Additions and rewrites for Editing pages

This adds:
- A multi-page Introduction section to sculpting
- User oriented sorting and more visual examples
- Fixing various out of date, missing or false information
- A new page for Expand to explain many use cases

Shortcut Changes:
- The shortcuts Shift R and Shift D to define density in sculpt mode have been remapped to R
- This change was done to prevent shortcut conflicts with Redo. Based on community feedback, not only this improves consistency across Blender, but the benefits of being able to redo certain operations outweigh the muscle memory adjustment.
- This change affects the Voxel Remesher, Dynamic Topology and the Hair Density brush

User Interface:
General:
- The icon preview shown in the material slots and material search menu will no longer be rendered for linked in materials. This would cause slowdowns and UI freezes every time the file is reloaded, since the preview is never stored in files
- More menus align their item labels when some items include an icon and some don't
- Font previews now differentiate better between Korean, Japanese, Simplified & Traditional Chinese

Viewport:
- Cancelling viewport orbit/pan/zoom & dolly is now supported (by pressing RMB), this allows orbiting out of camera or orthographic views temporarily

VFX & Video:
Optical Center in motion tracking:
- The internal storage of the optical center has been changed in the 7dea18b3aa.
- The change allows to change the underlying movie clip resolution (for example, when going from 4K footage to manual 2K proxy) without loosing the non-frame-centered optical center. This effectively fixes an issue when changing the media file would reset the optical center to the frame center.
- On a user interface the optical center is now refered in a normalized space: coordinate (0, 0) corresponding to the frame center, (-1, -1) the left bottom frame corner, (1, 1) is the top right frame corner. Another change in the interface is the removed Set Principal to Center button. Such dedicated button is not needed anymore since backspace on the optical center properties will do just that.

Sequencer:
- Sequence transform has a new filtering mode "Nearest (3x3)". This mode will use "Nearest" filtering when working in the sequencer, but during rendering it will perform a 3x3 sub-sampling, improving the quality of the final image.
- Copy drivers when strips are duplicated or pasted 4e9c6929c1d0.
- Added "Update Scene Strip Frame Range" operator 90e940686692060.

Add-ons:
Rigify:
- Ported the ability to generate Action Constraint layers from Cloud Rig

Storypencil:
UI Refactor: New Mode selector and settings for more discoverability of the add-on two main modes (Switch and New Window).
- In Switch Mode the audio file in the video sequencer is copied temporarily to the source scene allowing to keep audio in sync. This can be disabled in the Storypencil settings panel.
- IN/OUT strip range markers ar now showed in Switch Mode.
- TAB key can be used now to edit the strip scene under the timeline cursor.
- Bugs Fixed