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Overview ¶
The playbar controls the current time displayed in the viewer, playback of animation and simulation, and the playback range. The playbar also displays keys for the parameters in the Channel List, and you can edit keys directly on the timeline. The round keyframe button changes color based on the keys at the current time, and clicking it adds keys at the current time.
Playback controls, first row ¶
First frame
Moves the playhead to the start of the current frame range.
Play Backwards
Starts playing the animation in the current frame range backward.
Stop playback
Stops playing the animation.
Play forward
Starts playing the animation in the current frame range. The button turns into a pause button while playback is active. Pressing it again stops the playback.
Last frame
Moves the playhead to the end in the current frame range.
Current Frame
Displays the current frame number. You can use the ladder using the MMB drag or type a frame number.
Previous frame
Moves the playhead to the previous frame. At the start of the current frame range, this can be made to wrap to the end by enabling the Loop Backwards option on the Play looping 
button.
Next frame
Moves the playhead to the next frame. At the end of the current frame range this wraps to the start.
Playback controls, second row ¶
Global Animation Options
Opens the Global Animation Options window with settings for animation, including the total number of frames are in the current scene.
Open audio panel
Opens a window with settings for audio playback.
Play looping
This pop-up menu lets you choose how/whether playback loops when it reaches the end of the frame range. You can choose Loop (repeat), Play once (stop at the end), or Zig-Zag (repeat forward then backward). There is also an option to Loop Backward.
Real time playback
Toggles real-time mode. When this is on, Houdini will drop frames to try to maintain the correct FPS. When this is off, Houdini will display every frame even if this is slower than real-time.
Click to open the Global Animation Options window to choose realtime playback options.
Enable playback at fractional frames
Sets the frame rate for playback to a fractional increment. RMB-clicking the button lets you set the substeps directly from a list of preset options.
If you want to specify the substeps manually, then select Custom from the RMB options to open the Global Animation Options window. The fractional frames setting exists inside the Global Animation Options window as the Integer Frame Values & Step options.
When this button is pressed:
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Playing back your animation will play each fractional frame based on the selected step size instead of playing back whole integer frames.
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The Next frame / Previous frame buttons in the playbar will go to the next fractional frame instead of whole frame.
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Scrubbing along the playbar will scrub along fractional frames instead of whole frames.
Previous keyframe
Moves the playhead to the previous keyframe for the selected object.
Go to next keyframe
Moves the playhead to the next keyframe for the selected object.
Timeline ¶
The timeline is a graphical representation of the current frame range. The current frame is highlighted with a black box with a down arrow indicator. Keys on the Channel List appear as marks on the timeline. You can edit keyframes directly on the timeline using the MMB and draw rectangle selection selections using Shift+LMB.
See how key marks are color coded on the timeline.
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Go to a specific frame |
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Tip
A thin vertical line is displayed under the mouse cursor to indicate the frame number.
Time Range ¶
The time range controls are under the timeline. You can change the global frame range, and the frame range. You can also resize and move the frame range using a scrollbar.
The inner edit boxes surrounding the scrollbar are the start and end frame. The outer edit boxes ,with a lighter background color, are the global start and global end frame.
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Set the frame range |
There are two frame ranges: the overall frame range is set in the |
Set the total number of frames |
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Editing keys on the timeline ¶
You can edit keys directly on the timeline without opening the animation editor when it’s more convenient. Editing keys on the timeline is very similar to editing in the dopesheet.
The timeline only shows key markers for the channels in the Channel List.
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Move a single key along the timeline |
MMB click a green rectangle and drag to move keyframes in the timeline. You can MMB on an area without a key to make a quick one frame range selection. Once you have a selection, you have access to all the operations of a range selection. |
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Move keys along the timeline using a range selection |
Hold ⇧ Shift and click or drag to edit keyframes in the timeline. Holding ⇧ Shift puts you in “editing” mode instead of moving the playhead along the timeline.
(You can keep holding ⇧ Shift and select multiple ranges at the same time.)
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Hold channels |
This is a quick way to copy the values of the channels from one frame to another, such as when you want an object to ping-pong back and forth between two positions.
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Copy and paste keys |
Paste Copies keys from the clipboard into the current selection. Replace Replaces the current selection with the contents of the clipboard. Stretch/Paste Stretches the contents of the clipboard to fill the selection, if the new selection is a different size than when you cut/copied. Paste as cycle Repeats the contents of the clipboard to fill the selection, if the new selection is longer than when you cut/copied. Paste as cycle with offset Repeats the contents of the clipboard with offsets to fill the selection, if the new selection is longer than when you cut/copied. |
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Paste keys visually |
The visual paste options on the context menu let you interactively position the paste location with the mouse, instead of selecting it first and then pasting. First, cut or copy a set of keys. If you want to visually paste a repeat or cycle, select a longer range of frames than you have keys – the range will be filled with repeats/cycles when you paste.
Right-click in the timeline and choose one of the following… Visual replace Lets you interactively position the clipboard data on the dopesheet, replacing the current contents. Visual stretch/paste Lets you interactively position the clipboard data on the dopesheet. Stretches the clipboard data to match the current size of the selection. Visual paste as cycle Lets you interactively position the clipboard data on the dopesheet. Repeats the clipboard data to match the current size of the selection. Visual paste as cycle with offset Lets you interactively position the clipboard data on the dopesheet. Repeats the clipboard data with offsets to match the current size of the selection. Use the mouse to position the pasted keys on the timeline. Shift-click to paste the keys, or press ⎋ Esc to cancel pasting. |
Keyframing Controls ¶
The right side of the playbar focuses on keyframing controls. It features a large keyframe button with a drop-down menu button for quick access to keyframing preferences, a Channel List button showing an overview of the channel list, a channel list refresh button, a quick access button for the animation editor, and combo box for the Global Set Key preference.
Pressing the keyframe button with channels in the channel list will set a keyframe at the current time on all the channels or on the selected channels based on the Global_Set_Key preference. It does the same as pressing the K key.
Keyframing Modes
The keyframe button also shows the state of some Animation Preferences by using a different icon. You can quicky change Auto-Key and Auto-Commit animation preferences by clicking on the drop-down menu button next to the keyframe button. By default, Auto-Key is off and Auto-Commit is on. In this state, the keyframe button is rendered without any decoration. If you turn Auto-Commit off, the keyframe button will be rendered with a little check mark icon. This tells you need to always commit your changes before moving the timeline. In that state, the keyframe button will turn orange really often. If you turn Auto-Key on, the keyframe button is rendered with the label AUTO on it. In that mode, Auto-Commit has no effect, since Auto-Key adds as soon as you change a parameter value.
Tip
The button supports drag and drop. You can do a drag and drop from a parameter label on it to add channels to the Channel List. You can also drag from the Channel List button onto a Python Shell pane to get the list of hou.Parm in a python array.
Channel List Refresh
Clicking on the channel list refresh button forces a refresh of the Channel List from the selected nodes. The button also has a drop down menu to change Auto-Update Channel List, Keep Channel List Selection animation preferences.
Animation Editor
Opens the Animation Editor floating window.
Global Set Key
Controls the behavior of the keyframe button and the K key. You can choose from Key Pending, Key All Channels, Key Selected.
