From BlenderWiki

Editing Action Channels

The Action Editor offers a somewhat 'higher level' view of your animation, compared to what you can do in the Ipo Curve Editor. While the Action Editor can't edit the nature of interpolation, it

• Allows the animator to edit multiple channels at once
• Allows animators to edit multiple keyframes, from multiple channels at once

You cannot add channels themselves, which means you cannot add new animated properties from an Action Editor window – however, you can delete them!

Remember that only Ipo datablocks that have been set as “actions” (the small “man” button to the left of the Ipo type selector) will be shown/editable in the action editor.

Let’s repeat this one more time: when you edit an action, you also edit its underlying Ipo curves, and vice versa…

Note We describe here the editing done in Action Editor mode – the two others have the same or a reduced set of possibilities…

Selecting

The selection tools are available through the Select menu, and of course through their own shortcuts.

There are three different selectable elements:

• The keyframes (gray/yellow diamonds).
• The channels (in their left list).
• The markers.

The Column Select Keys sub-menu

Depending whether there are some markers or not, you have two or four options:

• On Selected Keys (K) – Selects all the keys that occur on the same frames as already selected keyframes.
• On Current Frame (CtrlK) – Selects all the keys that occur at the current frame.
• On Selected Markers (⇧ ShiftK) – Selects all the keys that occur on the same frames as selected markers.
• Between Selected Markers (AltK) – Selects all the keys that occur between and on the first and last selected markers.

Ahead In Time and Back In Time (AltRMB )

Selects all keyframes after (respectively before) the current frame included. The position of the AltRMB click (before or after the green current frame cursor) determines which “side” is selected.

Inverse All Channels (CtrlI), Inverse Markers (Ctrl⇧ ShiftI), Inverse Keys (CtrlI)

These three entries invert respectively the channels selection, the markers selection, and the keyframes selection.

Note that the CtrlI shortcut is common the both channels and keyframes – the type of selection it inverses depends on where the mouse cursor is when you hit the shortcut: channels when in the left channels list, and keyframes when in the main area.

Select/Deselect All Channels (A), Select/Deselect All Markers (CtrlA), Select/Deselect All Keys (A)

These three entries (de)select respectively all the channels, all the markers, and all the keyframes.

As above, the same shortcut (A) is used for channels and keyframes, it depends on where is the mouse cursor…

Border Select Channels (B), Border Select Markers (CtrlB), Border Select Keys (B)

These three entries start the border-select tool, respectively for the channels, the markers, and the keyframes.

As above, the same shortcut (B) is used for channels and keyframes, it depends on where is the mouse cursor…

And as usual with border-select tools, the LMB click-and-drag adds to the current selection, whereas the RMB (or AltLMB ) click-and-drag removes from the current selection.

Editing

As previously said, editing in actions is mainly a matter of re-timing keyframes – even though you can also add/remove some, and even edit their values, this isn’t the primary purpose of this editor.

Transformations

You can move and scale the selected keyframes with the usual grab (G) and scale (S) tools. Note that the scaling is done using the current frame (green cursor) as “center point”.

There are two more transformations specific to this window, also available through the Key » Transform sub-menu:

Grab/Extend from Frame (E)

This will start a standard “grab” operation, but only with the selected keyframes that are “on the same side” of the current frame as the mouse cursor. For example, if your mouse cursor is “before” the current frame when you hit E, only the selected keyframes with a timing below or equal to that current frame will be grabbed.

Time Slide (T)

This is a quite difficult tool to explain. Basically, it:

• Gets the whole time range defined by the currently selected keyframes.
• Gets the “frame” corresponding to the mouse cursor X-position when you hit T (it is then materialized as a thin vertical black line).
• Grabs this “mouse frame” forth and/or back, and proportionally “squeeze”/“expand” the in-between keyframes…

See the (Example of Time Slide operation) picture!

Example of Time Slide operation.

Just before hitting T…

Time slide started – note the vertical black line under the mouse cursor.

Time slid to the left – note how the soonest/latest keyframes do not move at all.

Time “over slid” to the right – the “right-side-mouse” selected keyframes are all stuck to the latest keyframes position…

As usual, you also have some transform (or auto) snapping options, available both through modifier keys or the Auto-Snap Keyframes drop-down list to the right of the window’s header:

No Snap

Default behavior, no modifier shortcut.

Frame Step (Ctrl)

Transformations are constrained on whole-frame steps (i.e. integer step values).

Nearest Frame (⇧ Shift)

Transformations are constrained so that the affected keyframes always exactly lay on (the nearest) frames (i.e. integer frame values).

Nearest Marker (Alt)

Transformations are constrained so that the affected keyframes always exactly lay on (the nearest) markers (note that as markers always lay on whole frames, this implies the previous behavior as well).

Snapping

You can use the non-interactive snapping options (⇧ ShiftS or Key » Snap) to snap the selected keyframes to:

• The nearest frame (⇧ ShiftS1 NumPad or Key -> Nearest Frame entry).
• The current frame (⇧ ShiftS2 NumPad or Key -> Current Frame entry).
• The nearest marker (⇧ ShiftS3 NumPad or Key -> Nearest Marker entry).

Note that you can also snap the current frame (i.e. green cursor) to the selected keyframes (when several non-synchronous keyframes are selected, the current frame is snapped to the median value…). Use the Ctrl⇧ ShiftS shortcut, as the Key » Snap » Current Frame -> Key menu entry doesn’t seem to work…

Mirroring

Like in the Ipo Curve Editor, it is now possible to “mirror” the selected keyframes over a line. This makes it easier e.g. to reverse an action. Four options are currently available (Key » Mirror » … sub-menu):

Current Frame (⇧ ShiftM1 NumPad)

Mirrors the selected keyframes using the current frame (green cursor) as the mirror-line.

Vertical Axis (⇧ ShiftM2 NumPad)

Mirrors the selected keyframes using frame 0 as the mirror-line.

Horizontal Axis (⇧ ShiftM3 NumPad)

Mirrors the selected keyframes using value 0 as the mirror-line (hence it mirrors the keyframes’ values, and not their timing…).

Selected Marker (⇧ ShiftM4 NumPad)

Mirrors the selected keyframes using the frame of the first (chronologically) selected marker as the mirror-line.

Inserting Keyframes

You can insert new keyframes at the current frame by hitting I. An Insert Key menu pops-up, with the following choices:

• All Channels – Inserts one keyframe in each Ipo curve of each action channel.
• Only Selected Channels – Inserts one keyframe in each Ipo curve of each selected action channel.
• In Active Group – Inserts one keyframe in each Ipo curve of each action channels belonging to the active group (light green colored – if there is no channel group defined, this does nothing).

Note that this way, you cannot control the values of the inserted keyframes: as within the Ipo Curve Editor, they get the current underlying Ipo curve values… However, you can also insert a keyframe into a given channel using its value slider, see below.

Duplicating Keyframes

You can duplicate the selected keyframes by hitting ⇧ ShiftD. As usual, the copies remain the only one selected and are placed in “grab” mode, so that you can move them away from the originals…

Copying Keyframes

As in the Ipo Curve Editor, you can copy one or more selected keyframes into a buffer, and then paste them into the same Ipo channels (but generally in another action and/or Ipo datablock!). This is done through two header buttons:

• The “copy” button (down arrow) copies the selected and visible channels/curves into the buffer.
• The “paste” button (up arrow) pastes the buffer content into the corresponding existing channels/curves of the current action/Ipo datablock.

Deleting Keyframes

You delete the selected keyframes by hitting X, and then confirming the pop-up dialog.

The X shortcut is area-dependent: if you use it in the left list part, it’ll delete the selected channels, whereas if you use it in the main area, it’ll delete the selected keyframes…

Key Values

If you show the curves’ sliders (View » Show Sliders), in the left channel list, you can also edit the value of the keyframes (i.e. their Y value in the Ipo Curve Editor window).

The usage of these sliders is very simple: as soon as you edit one of them, the related keyframe at the current frame is modified accordingly. If there is no keyframe on that Ipo channel at that frame, a new one is created. So, keyframe selection has no influence at all here.

There is one more important property related to a channel’s slider, available from its “channel property” panel (CtrlRMB -click on it, in the left area). In this panel there are two sliders that control the minimum/maximum values that the “value slider” can take (note that this does not affect the minimum/maximum values the underlying Ipo curve can take!).

Other Tools

You have the Key » Clean Action tool (O), which does exactly the same thing as the Clean Ipo tool of the Ipo Curve Editor: it removes/merges neighbor keyframes in the selected channels, that are too close in time and/or value (using a given threshold).

I don’t know what does the Key » Sample Keys (AltO) option…

Finally, in the same Key menu, you can change the Bézier handle types of selected keyframes, and the interpolation and extension modes of the underlying Ipo curves, see this page for more details on these topics.