Version History of Blender 2.57 (x64)

This is the first stable release of the Blender 2.5 series, representing the culmination of many years of redesign and development work.

What to Expect

  • Big improvements in stability. Since the last beta almost 500 bugs were fixed.
  • Feature complete - Although some of the 2.5 targets have been postponed, such as multi-window support showing multiple scenes, a full RNA data level dependency graph, or radial menus.
  • Changes - If you're used to the old Blenders, Blender 2.5 may seem quite different at first. Be prepared to read a bit about this, how to reconfigure things, and learn to use the new built-in 2.5 search functionality!

Open todos: get involved!

  • There's still topics that needs to be worked on before reaching the final 2.5x release target
  • First: check this log, you can find Known Issues at the bottom of the following feature description pages.
  • Second: check if the bug or issue has been added on our todo list in wiki.
  • This will save you (and us!) from reporting known issues! Bugs can be posted in the bug tracker or using Help ? Report a Bug from inside Blender 2.5.

User Interface

Updated GUI

Blender 2.5 has a new GUI layout, with updated graphic design and a new icon set. The GUI layout has been re-designed to be clearer, better organised and easier to navigate, and is fully customisable with Python scripting. Other improvements include a new file browser, customisable tool shelf and more. 


In Blender 2.53 we've implemented a new method for extending Blender with Python Scripts. These now are being distributed and stored as 'Add-ons" which you can choose to enable or disable each individually. This helps to keep the interface clean and well organized.

Custom keyboard shortcuts

Blender 2.5 has been designed from scratch to enable users to configure their own keyboard shortcuts. Key definitions are be grouped in "key maps", and each map can be fully customized and saved. Keymaps can also be configured for special input methods such as directional gestures and tweak events, any-key modifiers, or multi-key input.

Internal Architecture

Data access

Now all internal data in a .blend scene file, from individual vertices, to inter-object relations, to composite node UI positions, is fully accessible with a consistent system. This enables UI controls, Python Scripting API, the animation system and more, to access and edit all scene data consistently, while providing richer interaction and feedback such as contextual help, in-place keyframing and driver expression editing, and real world units of measurement.

64 bits for Windows, Linux & OS X

Next to Linux and Windows, we now support 64 bits versions for OS X too. This required a full recode of the low level windowing library to support Cocoa, which is good news for Blender's future on Macs in general!

Tool system

An "Operator" is the new generalized definition of a tool in Blender. This ranges from file load/save, UI layout management to adding and editing objects and its data. Because the Operator is generic, it can be called uniformly by hotkeys, menus, buttons, or via Python. Operators can be searched, chained (macros) and can provide interactive editing with real-time updates. 

Python Scripting

Blender 2.5 has a full re-implemented Python Scripting API. Anything a user can interact with via the UI - data, options and tools - is also available for scripters now. Scripts are being used for Importers/Exporters, for custom tools ("Operators"), for access to other render engines, and for extending the UI in various ways.

For the next 2.58 release the API will be completed with access to internal notifiers and events to track data changes or UI refreshes.


Sculpt and Multi-resolution

Sculpt mode in Blender has been optimized,  increasing drawing and editing performance significantly, and reducing memory usage to support more detailed models. New tools have been added and existing ones improved. Multiresolution meshes have also been rewritten, now available as a modifier to integrate better with the animation system, and preserving displacements when editing the mesh topology.

Paint Brushes

Blender's method of accessing brushes for painting tasks has been updated and streamlined. Brushes store all paint-related settings, such as size, strength, tool type, textures and influence curve, and can be switched between in the brush list box or with shortcut keys. As well as the preset brushes included with Blender, you can also save your own, and assign your own shortcut keys to them.

Sculpt Brush and Stroke Upgrade

In Blender 2.54 Beta the focus has been on bug fixing and stabilizing the scripting API in the form of a renaming operation to unify naming and changes to property creation and access.

Solidify Modifier

Blender 2.5 now includes a Solidify modifier, used to non-destructively add thickness to thin meshes (similar to 'shell' modifiers in other applications). Solidify allows you to model a simple thin mesh surface, and have a solid thickness automatically extruded by the modifier.

Animation System

F-Curves, Actions, NLA

One of the 2.5 specs is "make everything animatable". The implications of this didn't make it easy to just port things over, so a couple of important redesigns were needed: Individual properties are animated with F-curves, grouped into actions, and can be instanced and layered and mixed non-destructively in the NLA editor. Effects such as noise and enveloping can be added to animation curves and NLA clips with F-curve modifiers. 

Spline IK

Spline IK is a constraint which aligns a chain of bones along a curve. It is particularly well suited for rigging flexible body parts such as tails, tentacles, and spines, as well as inorganic items such as ropes. 

Animation Editors

The animation editors have had a complete refresh in Blender 2.5 with a new graph editor, supporting multiple objects and F-curves simultaneously, a scene-wide dopesheet, a redesigned Non-Linear Animation editor and new functionality for shape animation, driver, expressions and keying sets.


Smoke Simulation

Blender 2.5 includes a new fluid-based smoke simulation engine. Alongside this is capability to scale up a low-resolution sim, maintaining detail with wavelet turbulence. Smoke can be generated by input particle motion, and can be affected by colliding obstacles and force fields. The smoke data is output as voxels, which can be rendered as a volume.


Particle systems have had a refresh, now taking advantage of fully interactive animation playback and editing. New additions include particle path editing with brush tools, a new point caching system, new boids physics and hair dynamics using cloth simulation. 


Volume Rendering

Blender 2.5 includes a volume material, intended for rendering particles and gases such as smoke, clouds, and fire. All procedural textures are supported as data sources, as well as two new textures for rendering voxels (such as smoke sims) and point clouds. Various shading options are available from wispy mist-like volumes, to physically based scattering and self-shadowing. 

Ray tracing optimization

As part of the google summer of code, the ray trace acceleration system has had a complete overhaul, making it significantly more efficient and with support for new features such as instancing. Now multiple BVH based acceleration structures are available, in artists' terms, rendering some scenes up to 10x faster!

Color management

Blender 2.5 includes a first version of Color Management. Currently this is limited to ensuring Linear Workflow during the render pipeline - gamma corrected inputs are linearized before rendering, the renderer and compositor work in linear RGB color space, and is gamma corrected back to sRGB color space for display in the image editor.

Future work may include support for display profiles, LUTs, and finer grained control over input/output conversions.

Other rendering features

Additional rendering features in 2.5 improved bump mapping and image texture filtering, an initial version of deep shadow maps, color management (integrated linear workflow). 


More new features, that still needs to be documented on this page:

  • Installation paths and OS conventions
  • Windows version: Blender now starts with Command Prompt hidden
  • External Render Engine API
  • Python interactive console.
  • Scopes Display in the Image Editor
  • Non-blocking Reports in top header
  • Screw Modifier
  • Fluid Particles
  • Network Render
  • Game Engine Mode in UI
  • Approximate Indirect Light
  • Improved sequencer core: it's faster and needs less memory
  • GameLogic/Audaspace GSoC project merged
  • load binary data as .blend from memory
  • Installer for Windows installs since 2.56 in %USERPROFILE% by default
  • COLLADA support has been stabilized considerably, with improvements to mesh, material, light and node structures
  • BVH Motion Capture Export
  • SVG Vector Graphics Import
  • Blend file thumbnails for Windows and Gnome Desktop Environment.

Fixed Issues

  • Since Blender 2.56 Beta a lot of bugs have been fixed. This includes fixes to particles, sequencer, the scripting API, 3D view, Outliner, hotkeys, keyboard, GUI issues and many more.

Known Issues

Although we work hard on fixing all issues, there are still some things we know already are not fixed. 

  • Intel on-board graphics cards: Potential crashes when opening new window (user preferences, rendering)
  • Add-ons: Keymap changes get lost on loading .blend files.