From aa9b7cfd2055af8affce46e225590f1543745fa9 Mon Sep 17 00:00:00 2001 From: Bastien Montagne Date: Thu, 27 Jul 2023 18:02:08 +0200 Subject: [PATCH 1/3] Add page about blend-file compatibility support. See also https://projects.blender.org/blender/blender/issues/109151. --- manual/files/blend/compatibility.rst | 58 +++++++++++++++++++ manual/files/blend/index.rst | 1 + manual/files/linked_libraries/link_append.rst | 4 ++ 3 files changed, 63 insertions(+) create mode 100644 manual/files/blend/compatibility.rst diff --git a/manual/files/blend/compatibility.rst b/manual/files/blend/compatibility.rst new file mode 100644 index 000000000..2c8bafc2d --- /dev/null +++ b/manual/files/blend/compatibility.rst @@ -0,0 +1,58 @@ + +************* +Compatibility +************* + +Blender can open blend-files saved with both older versions of the software (backward compatibility), +and newer ones (forward compatibility). This comes with some limitations though. + +.. tip:: + + When having issues with opening much older (or newer) blend-files, it can help to use a few + intermediary Blender releases to perform conversions by smaller steps. + + +.. note:: + + Here is a `more exhaustive documentation `_ + about compatibility handling, in the developpers documentation. + + +Backward Compatibility +====================== + +Opening older files and converting them for the current version of Blender is usually straight-forward. +It is expected to give very good and usable results. + +There can be major feature changes, for which the backward compatibility will only be ensured for +a limited amount of time. For example the changes to the animation system that happened during the +Blender 2.5x project. This will never be less than a full major release cycle (i.e. two years +at least). + +Forward Compatibility +===================== + +Loss of Data +------------ + +Forward compatibility is inherently harder to ensure, and loss of feature should always be expected +when opening a blend-file saved with a more recent version of Blender. + +A warning is shown in the UI when editing a more recent blend-file. Trying to overwrite it (with a +simple 'Save' operation) will also show a confirmation popup, as this could make that loss of data +permanent. + +Complete Incompatibility +------------------------ + +When Blender switches to a new major version release (e.g. from 3.x to 4.0), there can also be major +changes that will make the blend-file fully incompatible with older versions of Blender. + +In such cases, older Blender will fail opening (or appending/linking from) the newer blend-file, with a +message stating which minimal version is needed to open it. + +In such cases, the last LTS release of the previous release cycle will be kept compatible with the newer +file format version, and will be usable as converter between both versions. + +For example, Blender 3.6LTS can open files from Blender 4.x, and will perform the necessary conversion +such that when re-saved from 3.6, the files become compatible with all 3.x Blender versions. diff --git a/manual/files/blend/index.rst b/manual/files/blend/index.rst index fb27634c0..9f10f247b 100644 --- a/manual/files/blend/index.rst +++ b/manual/files/blend/index.rst @@ -7,6 +7,7 @@ :maxdepth: 2 open_save.rst + compatibility.rst packed_data.rst previews.rst rename.rst diff --git a/manual/files/linked_libraries/link_append.rst b/manual/files/linked_libraries/link_append.rst index d289f0258..b63f71954 100644 --- a/manual/files/linked_libraries/link_append.rst +++ b/manual/files/linked_libraries/link_append.rst @@ -11,6 +11,10 @@ Newly added collections types are available in :menuselection:`Add --> Collectio Look in the *Outliner*, with display mode set to *Blender File*, to see all your linked and appended data-blocks. +.. note:: + + It is not possible to Append or Link data from :doc:`much newer blend-files ` + .. _bpy.ops.wm.link: -- 2.30.2 From 374906c39f8c3ab522010cdc5b67993f5075709d Mon Sep 17 00:00:00 2001 From: Aaron Carlisle Date: Sun, 6 Aug 2023 21:02:52 +0200 Subject: [PATCH 2/3] Cleanup: Formatting --- manual/files/blend/compatibility.rst | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/manual/files/blend/compatibility.rst b/manual/files/blend/compatibility.rst index 2c8bafc2d..c69481897 100644 --- a/manual/files/blend/compatibility.rst +++ b/manual/files/blend/compatibility.rst @@ -11,11 +11,10 @@ and newer ones (forward compatibility). This comes with some limitations though. When having issues with opening much older (or newer) blend-files, it can help to use a few intermediary Blender releases to perform conversions by smaller steps. - .. note:: - Here is a `more exhaustive documentation `_ - about compatibility handling, in the developpers documentation. + Here is a `more exhaustive documentation `__ + about compatibility handling, in the developpers documentation. Backward Compatibility @@ -26,8 +25,8 @@ It is expected to give very good and usable results. There can be major feature changes, for which the backward compatibility will only be ensured for a limited amount of time. For example the changes to the animation system that happened during the -Blender 2.5x project. This will never be less than a full major release cycle (i.e. two years -at least). +Blender 2.5x project. This will never be less than a full major release cycle (i.e. two years at least). + Forward Compatibility ===================== @@ -38,9 +37,10 @@ Loss of Data Forward compatibility is inherently harder to ensure, and loss of feature should always be expected when opening a blend-file saved with a more recent version of Blender. -A warning is shown in the UI when editing a more recent blend-file. Trying to overwrite it (with a -simple 'Save' operation) will also show a confirmation popup, as this could make that loss of data -permanent. +A warning is shown in the UI when editing a more recent blend-file. +Trying to overwrite it (with a simple 'Save' operation) will also show a confirmation popup, +as this could make that loss of data permanent. + Complete Incompatibility ------------------------ -- 2.30.2 From 36c560c9201c20ad7c7a543b9007f9c3b007fd17 Mon Sep 17 00:00:00 2001 From: Aaron Carlisle Date: Sun, 6 Aug 2023 21:09:48 +0200 Subject: [PATCH 3/3] Cleanup: Remove file extension from doc link --- manual/files/linked_libraries/link_append.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/manual/files/linked_libraries/link_append.rst b/manual/files/linked_libraries/link_append.rst index b63f71954..7911e66d4 100644 --- a/manual/files/linked_libraries/link_append.rst +++ b/manual/files/linked_libraries/link_append.rst @@ -13,7 +13,7 @@ Look in the *Outliner*, with display mode set to *Blender File*, to see all your .. note:: - It is not possible to Append or Link data from :doc:`much newer blend-files ` + It is not possible to Append or Link data from :doc:`much newer blend-files ` .. _bpy.ops.wm.link: -- 2.30.2