NOTE: this is a direct dump of https://wiki.blender.org/index.php/Dev:Source/Development/Todo/Editors (without cherrypicking the valid items)
3D View: Drawing
- GLSL drawing doesn't support custom clipping. [http://www.opengl.org/discussion_boards/ubbthreads.php?ubb=showflat&Number=260488] and T26363.
- Helper objects (empties, force fields, lattices, etc) are not scaling to grid cell size on add. T32219
- Some Game Engine settings (like transparency) draw in viewport, also when render engine is not "Game". T31294
- Lattice drawing colors are not part of Theme Colors yet. T35575
- "Show weights" in edit mode does not work with (vertex generating) Modifiers T35597
- Inconsistent between displayed objects in "Only Render" viewport and actual render T37951
- Partial redraws during viewport render leads to window split icon flush T40464
- GLSL does not support face tile T40627
- Image empties are not drawn correctly in bbox/wire modes, due to lack of z buffer (T41117).
- Region overlap might allow some events to be passes to the vewport even if they're invoked from the button, (T40649)
- 'Show Weight' option in edit mode in inconsistent in wiredraw mode, whith modifiers defined as 'preview' it shows solid, and otherwise it does not show weights at all on deformed wire...
- Axis projection for objects movement might be made more friendly (T37009)
- Viewport AO doesn't support anti-aliasing (T47866)
- Missing attributes for GLSL shaders:
- Generated coordinates for curves T51886
3D View: Interaction
- Continuous grab doesn't function when switching view3D modal. See T28486, T40536.
- View rotate snapping [not only numpad] could support switching to ortho when Auto Perspective is enabled. See T53904
- Change the make_links (editors/object/object_relations.c) operator to show a menu with the properties that we can copy for every object type. Also finish to port the rest of options from 2.4x to 2.5 (like Camera data).
3D View: Other/Unsorted
- Image Sequence & Movie texture is not being updated on frame advance (using textured solid and multitexture textured shading modes, in 3d window). GLSL materials do update.
- Issues with grid due to floating point precision T37037
- Better communication of when game engine is running T39889
- Moving objects to invisible layers in edit mode disables the mode switch operator T40526
- Bevel vertices with no connected faces T35649
- "Exploding" smoke while scaling collision object T43220
- Image drawing is using glDrawPixels, making it only support unfiltered zooms. A switch to texture drawing would cause slowdowns though... should be compensated by switching to GPU operations for all drawing and painting options. And solve handling huge images (8k or more).
- While painting in sequences or movies, and having same sequence update live in compositor, black frames can appear. This is because images get moved to linear color inside composite, and paint system is accessing the same data. Both color management and image buffer 'owning' needs better handling.
- Image repeat is currently limited by 0.25 sec, need better approach drawing tiles here ((T30648))
- Improve feedback on unsaved painting when saving .blend. See T34235. Changing alpha settings or source type also causes image reload and loss of paint (T36254).
- Scopes updates are relatively slow and run in UI thread, which causes serious blocking and delay during render and compositing. Should probably be run as a separate job (workaround is to hide scopes during render/composite). See T36239, T36393
- Undo in Object mode in 3DView erase any non-saved painting on textures (T38893).
- Movie length is not calculated on load for Movie/Sequence type of sources (T51989)
- Find out how UV/Image editor should track other editors or the active object when setting images or uv maps. See T33055.
- Image editor in UV edit mode does not do real face tessellation which ends up with some artifacts for concave faces. See T31074.
- Individual origin support for UV islands http://lists.blender.org/pipermail/bf-funboard/2015-June/006219.html
- Animated properties currently don't work on single-image strips without blend mode, see T21378
- Strip blend mode "replace" doesn't allow animation
- Scene strip preview drawing prevents RMB insert-key on buttons. Use autokey, disable preview, or use graph editor for now. (This is a todo after 2.5)
- One solution is to implement "animation overrides" as detailed in this, see T25020
- Preview image / scopes have no view navigation (zooming, scrolling).
- Improve/replace current plugin architecture, see T22579
- Add a check to the preview renderer to detect whether graphics cards support off-screen render, so that people whose graphic cards can't handle those textures get better feedback. See T24656 and T22081
- Sound strip volume is only evaluated once per frame, so animating the volume leads to audible volume artifacts, see T24194
- Built-in replace/alpha/etc effects only work when there's a strip below. Could work for single strip too.
- Changing the pitch of a clip does not really change the pitch but changes the speed, see T28533
- Video dimensions aren't detecting correct for some codecs (leading to black "outline" on the bottom or right of shot). See in comments for T26837
- Movie strips aren't getting cache-limited which leads to high memory usage by internal anim structure fields.
- Cache invalidation doesn't happen reliably due to lack of dependency graph, T32206
- 10bit movie files are internally reading as 8bit byte, T34755
- All images are cropped to the render resolution inside Input strips, making effects like Transform less useful, see T35028.
- Scopes meters display could be improved from the UI POV, see feedback from T38004
- Some video formats generate huge mem usage with FFmpeg, requires making FFmpeg frames cache-managed (T37166, T45570)
- OpenGL render from sequencer ignore Anti-Aliasing settings. T43101
- Movie files with multiple sound tracks are only using first audio track T46449
- Recursive sequencer rendering doesn't always give expected animation T49261
- Adding a scene strip to VSE in the same scene makes results vary depending on scene start frame T50139
- Cutting a strip that is crossfaded causes the crossfade effect input to be changed to the wrong cut strip T50877
- Global undo doesn't work with editing text. (also mentioned in Interface category) (T24543)
- Old todo: text files are default included in .blend files, no support for external text works, nor does it support relative paths (T25328)
- Tab width is just a display option and it's not effect on indentation. See (T28441).
- Uncomment indented text in python editor doesn't work, T39314
- Datablocks view
- Does not remember state yet after save/load.
- Needs a system for viewing e.g. a million vertices, right now can run out of memory.
- Button drawing style would be nice to have as it was before without border.
- Calculation of width of data in columns needs revision. Currently uses hardcoded width hack
- RMB menu items should be reviewed (see (T29229))
- Recursive toggling hide / hide_select / hide_render is possible by holding Ctrl, but there is no way to keyframe all children recursively (should be Ctrl + I).
- More appropriate way to indicate that a data block such as a line style cannot be unlinked, rather than the warning message "Not yet implemented". See T37070.
- add the ability to run a command in another context (using the mouse, text dnd)
- Add support for FILE_OT_directory when used with linking or appending to type in names that include blend paths and proceeding ID groups such as /tmp/foo.blend/Scene/
- More expectable default folder for file selector T31314
- Bookmarks are allowed to be added when browsing inside a .blend file, however - this can't be used.
- Investigate supporting windows hidden file attribute T36102
- Horizontal layout doesn't trigger properly correct sliders when panels are larger than what fits in area (see also (T22657)).
- Have some way to specify which AnimData block Action Editor's action field gets/sets from T37512
- Multi-Dimensional arrays such as UV's or Matrices don't have access through animation path creation and lookup functions.
- The names of sub-structures are not shown in a very useful way in the dope-sheet, (T33178)
- View-Selected isn't centering vertically T36069
- Mocap data draws keylines for every frame in Timeline, obscuring "current frame". (T36381)
- Animation editors do not show anim data for "transient" ID blocks (node groups, textures) T36744. See also [http://lists.blender.org/pipermail/bf-committers/2012-April/036256.html discussion on bf-committers]
- Review the way F-Curve modifiers are evaluated/applied, currently they do not for a real stack T36645…
- Dopesheet currently doesn't sort/reorder keyframes on each transform step update (like the Graph Editor does). While the curves may look a bit weird in the Graph Editor mid-transform, there are no lingering effects of that. For now, it's not worth the trouble/effort to fix this. T38692
- Would be nice to support context-dependent units for modifiers, see T42705
- Allow separate RGB + A channels in Output File and Image nodes (Image + Alpha sockets), for the same RGBA file/layer. See [http://projects.blender.org/tracker/?func=detail&atid=498 report]
- Create a new widget for RGB(A) curves that allows display+edit of individual components. The CurveMapping widget requires a single "active" (cumap->cur) component for display and editing, which requires a lot of clicking to switch between components.
- Frame nodes draw a label directly against the backdrop of the node body. Depending on the frame node color this can give too little contrast (uses same color as regular node labels, doesn't work well on dark colors). Best would be a 2-color label with a darker outline, seems we have no precedence for this yet (T39317)
- Undo with linked node groups creates additional users T39552
- Once flags/types of sockets are copied from node group instance to node group they are never updated, even when changing node group itself T46406
- Add buttons to change UVMaps order. As this is very important for GameEngines (Unity3D, Unreal, jMonkey, Ogre3D). They use UVTexCoord1, UVTexCoord2... order. Here is screenshot for explanation http://i.imgur.com/MbsBh2l.png