diff --git a/manual/files/blend/compatibility.rst b/manual/files/blend/compatibility.rst new file mode 100644 index 000000000..c69481897 --- /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..7911e66d4 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: