Animation

Animation Editors

Linking animations to an Object

  • When adding a new animation to an object via Action Editor or '< New >' in the NLA Editor, the mesh gets a "link" to that animation.

    • This may not be desirable most of the time, especially when using the NLA Editor to organize animations.

  • This "link" can be checked in the following ways:

    • Check if there is any animation in the 'orange slot' ("animation slot") of the NLA Editor.

    • Check if there is any animation inside the Mesh, in the 'Outliner -> View Layer' tab.

      • Editing an Action via 'Start Editing Stashed Action' in the NLA Editor makes the animation appear in this session, but after finishing the edit, it disappears.

    • Check if there is any animation open in the Action Editor.

      • Editing an Action via 'Start Editing Stashed Action' in the NLA Editor makes the animation appear in this session, but after finishing the edit, it disappears.

Comparison of Animation Editors

  • The difference between Timeline and Dope Sheet Editor is:

    • Timeline advantages:

      • Allows changing Playback options (sound, display, etc.) and Keying options (placing a new keyframe).

      • Allows controlling animation playback: Play, Pause, rewind, etc.

    • Dope Sheet Editor advantages:

      • Allows slightly deeper editing of animation keyframes; e.g., handle visualization.

  • Difference between Dope Sheet Editor and Action Editor:

    • Dope Sheet Editor advantages:

      • Can view multiple actions from different meshes, while Action Editor only shows 1 action at a time.

      • Can view and edit animation of any mesh, regardless of which mesh is selected. Action Editor only shows animations of the selected mesh.

        • Even with 'Only Show Selected' unchecked; this option doesn't make any difference when using Action Editor.

    • Action Editor advantages:

      • Can rename, create new Actions, save an Action (click the shield icon), and unlink an Action from a mesh; animations are never deleted here.

      • Has an extra option in the Marker tab.

      • Can interact with the NLA Editor.

      • Right-hand panel is always open, without selecting a random track in the Action; tabs of both editors are identical.

    • Apart from these differences, both are exceptionally similar.

  • What to use:

    • Use only Timeline and Action Editor; Dope Sheet Editor is replaceable and obsolete compared to Action Editor; Timeline has the same advantages as Dope Sheet Editor over Action Editor.

Animation Editing

Workflow: Using NLA Tracks (Timeline + NLA + Action Editor or Dope Sheet Editor style)

  • Creating animations for a new object:

    • Options:

      1. Select the object and create Keyframes for it (pressing I).

      2. Select the object and click 'New' at the top center of the Action Editor.

    • Either option gives the mesh an "Animation Slot". A 'Push down' can be done on this animation to move it into an NLA Track.

      • The object cannot  have more than 1 "Animation Slot" associated with it.

      • The object can  have more than 1 Animation Track associated with it.

    • The animation filling the "Animation Slot" occupies the orange region of the NLA Track; i.e., the "Animation Slot" corresponds to an animation that belongs to an object but has never been 'Pushed down'.

  • Creating new animations:

    • Options:

      1. Click '< No Action >', go to the right-hand side of the NLA Editor, and click 'New'.

        • Problem:  Animations created here are protected. While used in an NLA track, they are protected. Otherwise, they are not.

          • To fix this, open Action Editor, select the animation, and click the shield icon. Then check X to prevent linking the animation to the selected mesh.

      2. Action Editor Only  Click 'New' at the top center of the Action Editor.

  • Deleting existing  animations:

    • Options:

      1. Go to 'Outliner -> Blender File -> Actions' and delete the desired animation.

  • Adding new Tracks:

    • Options:

      1. Click 'Add -> Add Tracks' in the NLA Editor.

      2. Create a new Action and 'Push Down' it. Can be done via:

        1. 'Push down action' button in NLA Editor.

        2. 'Push down' button in Action Editor.

  • Removing Tracks:

    • Options:

      1. Select the track in the left-hand side of the NLA Editor and press Delete or X.

      2. Click 'Edit -> Delete Tracks' in the NLA Editor.

  • Adding existing  animations to a Track:

    • Options:

      1. Press 'Shift + A' in the NLA Editor.

      2. Click 'Add -> Add Action Strip' in the NLA Editor.

    • By default, a track/~some element of the track should be selected.

    • If the Timeline is over an animation within the track, the new animation will be added to a new  track.

    • If the Timeline is not over an animation within the track, the new animation will be added to the same  track.

  • Removing animations from the Track:

    • Options:

      1. Select the animation in the track and press Delete or X in the NLA Editor.

      2. Click 'Edit -> Delete Strip' in the NLA Editor.

  • Make NLA Editor stop affecting an object without Tracks:

    • Options:

      1. Click 'Remove Empty Animation Data' on the left side of the NLA Editor; this deletes any empty Tracks.

Workflow: Using Loose Actions (Timeline + Action Editor)

  • Creating animations for a new object:

    • Options:

      1. Select the object and create Keyframes for it (pressing I).

      2. Select the object and click 'New' at the top center of the Action Editor.

    • Either option gives the mesh an "Animation Slot".

      • The object cannot  have more than 1 "Animation Slot" associated with it.

  • Creating new animations:

    • Options:

      1. Click 'New' at the top center of the Action Editor.

      2. Click 'New Action' icon at the top center of the Action Editor; it is between the Shield and X icons.

  • Deleting existing  animations:

    • Options:

      1. Go to 'Outliner -> Blender File -> Actions' and delete the desired animation.

  • Limitations:

    • This method makes combining animations more difficult.

Animation Baking

Rigify Bake: Action Snap 'IK->FK'

  • When to use:

    • .

  • Click the 'Action' button in 'IK->FK (~IK_name)' for each IK Bone in the Rigify Addon 3D View panel.

  • How it works:

    • Automatically performs 'Snap IK->FK' for each frame of the current animation, then creates a Transform Keyframe for that bone.

    • Works regardless of whether the Rigify Rig is in IK or FK mode.

  • When baking:

    • Generated Keyframes will overwrite current Keyframes of the current animation.

      • Replacement is only  done on IK Bone Keyframes; if the animation is FK and 'Slow IK Bake' is done, the animation will contain both FK and IK Bone Keyframes.

    • Created Keyframes:

      • Action 'IK->FK (foot)':

        • foot_heel_ik

        • foot_spin_ik

        • foot_ik

        • toe_ik

        • thigh_ik

      • Action 'IK->FK (hand)':

        • hand_ik

        • upper_arm_ik

  • (Optional) Fix imperfections:

    • Sometimes it’s better to do this while the animation is 'paused', or perhaps 'paused at frame 0', or maybe with Rig in Clear Transform.

    • IK keyframes for 'upper_arm_ik' can sometimes bug. Often, these keyframes can be safely deleted.

    • Note: 'Slow IK Bake' results are slightly inaccurate compared to FK animation. Can be checked by turning off Rig IKs before deleting FK Keyframes. However, the motion difference is almost imperceptible.

  • If you want the animation to contain only IK Bones (for clarity and consistency), Keyframes of exclusive FK Bones  can be safely deleted.

    • 'Exclusive FK Bone Collections' are based on 'Leg (FK)', 'Leg (Tweak)', 'Arm (FK)', and 'Arm (Tweak)'. 'spine_fk's have no IK counterpart, i.e., 'spine_fk's are regular Bones , as are 'torso', 'hips', 'shoulder', 'neck', 'head', 'root'.

    • Tweak Bones  are regular Bones , but as no ready animations affect Tweak Bones, any Keyframe with 'tweak' in the name can be safely deleted.

  • Tip for deleting Keyframes: hide the exclusive FK Bones  Bone Collections in the View3D tab, press A (select all), and delete their tracks in the Action Editor.

General Bake: Pose -> Bake Action

  • When to use:

    • .

  • Rigify Rig -> Pose Mode -> Select all Bones -> Bake Action.

    • 'Frame Step' = 1.

      • Unknown purpose.

    • Uncheck 'Only Selected Bones'.

      • Leaving checked can hinder animation playback when muting Armature constraints.

      • Leaving unchecked allows animation playback when muting Armature constraints.

      • Despite the same number of Tracks in the 2 generated animations, unchecking 'Only Selected Bones' creates more keyframes for hidden bones.

        • Example: simple walk comparison in Godot showed 20 more Deformation Bones tracks for the 'unchecked' case than the 'checked' case.

      • This option is tricky and hard to decide. If doing 'Clear Constraints', keep it checked; otherwise, leave unchecked.

    • Check 'Visual Keying'.

    • Uncheck 'Clear Constraints' and 'Clear Parents'.

      • Leaving these checked breaks the relationship between Rigify Rig and Proxy Rig.

    • 'Bake Data' = Pose.

General Bake: (IK->FK Constraints + Bake) + (Pose -> Bake Action)

  • When to use:

    • .

  • Makes Target Rig IKs use 'Copy Rotation' / 'Child Of' from corresponding Source Rig FKs or Target Rig itself.

    • Not preferred, as constraints handling can be tricky if you want to disable them.

    • Observed '~unintended snap' in 'Red IK controller arrows'; seems characteristic in some videos.

      • Causes a ~teleport effect of the limb, which is bad.

  • Bake using 'Bake via Pose -> Bake Action'.