How you preview compositions, layers, and footage has changed significantly in After Effects CC 2015 (13.5). Previews are now easier to start, interactive, and configurable.
RAM Preview no longer used for previewing:
After Effects still caches frames in RAM for real-time playback. However, starting such a preview is no longer a unique command in After Effects, so the term “RAM Preview” is no longer used. It’s called “Preview” now.
Spacebar to start a preview
Spacebar can now start a preview that optimizes frame caching for real-time playback, and that also plays audio. (Both are formerly unique features of what used to be called “RAM preview”.)
You can configure the preview behaviors for each of the preview keyboard shortcuts: Spacebar, Numpad 0, and Shift + Numpad 0. If you want spacebar to start a preview with audio that also displays active layer controls, you can do that now.
In previous versions of After Effects, clicking anywhere during a preview stopped playback. In After Effects CC 2015 (13.5), you can work in your composition or project at the same time that you preview a composition, layer, or footage. Uninterrupted previews necessarily changes the behaviors of starting and stopping previews. Learn more about the interactive performance improvements that made uninterrupted previews possible in this article.
- Real-time playback still requires that rendered frames be cached to RAM. While it is possible for simple compositions to render and cache faster than real time, previewing always caches frames to RAM before playback regardless of the composition content.
- There is no new use of the GPU during previews. The changes in After Effects CC 2015 (13.5) are all related to optimizing CPU resources.
You can now make changes to effects in the open project while a preview is playing back in After Effects.
In previous versions of After Effects, after you started a preview in a composition, layer, or footage viewer, clicking anywhere in the user interface would stop playback of that preview. In After Effects CC 2015 (13.5), preview continues to play back until you take an explicit action to stop it, such as a keyboard shortcut like spacebar. Read “stop a preview” below for specific actions that stop a preview.
When you preview a composition you can modify its layers in the Timeline, Layer, or Effect Controls panels. After Effects immediately begins to cache the updated frames, which will cause the preview frame rate to slow down until the new frames are cached. However, you cannot make modifications inside the previewing Composition panel because clicking in the panel stops the preview.
To modify composition by clicking in the Composition panel during a preview, for example to modify a mask path, open a second viewer panel for the same composition and make modifications there. Changes in the non-previewing viewer are reflected in the Composition panel where the preview is playing back.
You can make modifications during a preview in any non-previewing Composition, Layer, or Footage panel. More examples of what you can do:
- Create new layers, including subcompositions, and modify them.
- Apply or remove effects and keyframes, and change the values of any property or keyframe.
- Import footage and change interpret footage settings of any footage.
- Add compositions to the render queue and modify settings or render item order. Starting the render queue stops previews.
- Rearrange the workspace, including opening new Composition, Layer, or Footage panels.
- Change the view settings of a Composition, Layer, or Footage panel. For example, display the alpha channel, zoom in or out, switch from a single to a 4-up view, or change the 3D view.
As noted above, any time you make a change that affects the frames being previewed, the preview frame rate slows down while the new frames are rendered and cached.
With the ability to modify a composition during a preview, there is a distinct difference between the current time and the preview time.
In After Effects, the current time in a composition is the frame at which many actions are recorded, such as where keyframes are added. The current-time indicator (CTI) and the current time display in the upper-left corner of the Timeline panel indicate the current time.
During a preview, the CTI now draws a vertical blue line through the time graph area of the Timeline panel. This line helps to identify what keyframes or other points of interest are at the current time.
The preview time of a composition is different from the current time. The preview time corresponds to the frame displayed in the Composition panel during a preview. The preview time is indicated by the preview-time indicator (PTI). The PTI is the vertical red line through the time graph area of the Timeline panel which moves left-to-right during a preview. The time display at the bottom of the Composition panel also indicates preview time. (In previous versions of After Effects, the preview time or the preview-time indicator did not have proper names.)
As in previous versions of After Effects, the CTI in the Timeline panel does not move during a preview. If you drag the CTI during a preview, playback stops to display the frame at the new current time.
To move the CTI without stopping a preview, hold the Option (Mac OS) or Alt (Windows) key while you either drag the CTI or click in the time ruler. If you also hold the Shift key while you drag, the CTI snaps to keyframes and other points of interest, as it would when preview is not playing back.
Other methods to change the current time do not stop a preview.
In addition to the ability to modify a composition during a preview, After Effects CC 2015 (13.5) changes how you can start and stop a preview. Preview behaviors for the preview keyboard shortcuts can be customized with new controls in the Preview panel. The spacebar by default now starts a preview that caches for real-time playback and that plays audio.
Because these changes have dissolved the differences between the old RAM Preview and Standard Preview (spacebar) behaviors, those terms are no longer used in After Effects. Preview has been unified, with user-configurable behaviors.
- The term “RAM Preview” is no longer used to describe a separate preview mode. The RAM Preview button has been removed from the Preview panel.
- Spacebar now starts a preview that plays audio and optimizes frame caching for real-time playback.
- Preview behaviors for the spacebar keyboard shortcut can now be configured.
- New controls in the Preview panel allow you to configure preview behaviors per-keyboard shortcut: audio, looping, caching, range, and layer controls.
- New range option: Work Area Extended By Current Time.
- When caching a preview, After Effects starts playback immediately. Audio plays, if enabled. When frames can be cached faster than real time, the playback speed is limited to the real-time frame rate.
- Audio can now play with all previews, regardless of how the preview was started.
- When the preview frame rate is slower than real time (for example, during caching), audio is muted by default. A new preference allows you to choose whether to mute audio or to play audio. If you choose to play audio, the audio stutters to maintain sync when the preview frame rate is slower than real time.
- Explicit action is required to stop a preview because previews are not interrupted while you modify a project or composition.
Audio-only preview has not been incorporated into the unified preview behaviors. Pressing Numpad period (.) or Option + Numpad period (.) (Mac OS) or Alt + Numpad period (.) (Windows) still engages an audio-only preview. These shortcuts are not configurable or affected by the new Preview panel controls.
The term “RAM Preview” is no longer used in After Effects, and the RAM Preview button in the Preview panel has been removed. The new preview behaviors have dissolved the differences between the old RAM Preview and Standard Preview (spacebar) behaviors. The term “preview” is now used to describe playing a composition, layer, or footage viewer in After Effects, regardless of the behaviors.
While the term “RAM Preview” has been removed, the behavior of caching frames until RAM is full still exists, although the underlying code has been rewritten. Caching frames until RAM is full is now enabled by setting the Preview Favors control to Frame Rate. This and other behaviors associated with RAM Preview and Standard Preview, such as whether layer controls are shown during preview, are now user-configurable.
Pressing spacebar now starts a preview with audio and caches the frames until available RAM is filled, so that real-time playback can occur. This will help both new and experienced users of After Effects feel comfortable with using spacebar to start previews.
In previous versions of After Effects, before new users learned about RAM Preview they would first reach for the spacebar key. The resulting preview probably wasn’t in real time and never played audio, which caused confusion and generated many requests for Help.
Experienced After Effects users working on a laptop or other keyboard without a numeric keypad will also appreciate the ease of starting a cached preview with the spacebar key.
Pressing Numpad 0 starts a preview that is substantially identical to RAM Preview in previous versions of After Effects.
The preview settings for both keyboard shortcuts can be configured in the updated Preview panel, including resetting spacebar to behave similarly to previous versions of After Effects.
The Preview panel has been updated to allow you to configure the behaviors for any of the keyboard shortcuts that start a preview, including spacebar. To change the behaviors for a keyboard shortcut, first select it from the context menu, then change the options as desired.
Panel height snap points:
When you change the height of the Preview panel, it will snap to three different points to show:
- Transport controls only
- Transport controls and context menu
- All controls
Pressing the Play button will start a preview with the settings currently displayed in the Preview panel.
This means the Play button’s behavior will change when you select a different Shortcut. For example, if Shortcut is set to Spacebar and Play From is set to Current Time, pressing the Play button will start preview from the current time. If you change Shortcut to Numpad 0 and this causes Play From to change to Start of Range, pressing the Play button will start preview from the beginning of the range.
When you start a preview with Preview Favors set to Frame Rate, the Play button will change to a “cache and play” icon while frames are being rendered and cached. Pressing the Play button in this state will interrupt rendering and caching and play back the cached frames, and the Play button changes to the Stop icon.
Click the Stop icon to stop a preview.
The Composition > Preview > Play Current Preview menu command is linked to the Play/Stop button. Choosing this menu command gives the same result as pressing the Play/Stop button.
The Loop control is now remembered for each keyboard shortcut. Ping-Pong loop mode is no longer available.
The Mute Audio control is now remembered for each keyboard shortcut. Audio can be muted or unmuted during a preview by clicking this button; when you do so the state of the Mute Audio control is applied to the shortcut that was used to start that preview, and will affect the next preview you start with that shortcut.
Choose between the three different keyboard shortcuts that can start a preview to configure their behaviors: Spacebar, Numpad 0, and Shift + Numpad 0. The Play/Stop button uses the behaviors of the currently displayed keyboard shortcut. See this article for the default configurations for the three keyboard shortcuts.
Reset: Click the Reset button to restore the default preview settings for all the shortcuts. Hold the Option key on Mac OS or Alt key on Windows and click the Reset button to change the settings of the keyboard shortcuts to closely match their behavior in previous versions of After Effects.
Choose to optimize the caching and playback behavior for better Frame Rate performance or unlimited Length of preview. This control is similar to choosing between RAM Preview and Standard Preview in previous versions of After Effects; however, there are several differences in After Effects CC 2015 (13.5).
When Preview Favors is set to Frame Rate, After Effects renders and caches frames until the available RAM is filled and then plays the cached frames in real time. During the rendering and caching phase, frames are rendered and cached as fast as possible. Playback of cached frames begins immediately, but no faster than real-time frame rate. If the cache fills available RAM before all frames in the range are rendered, only the frames in the cache are previewed. When the caching phase is completed, real-time playback will begin from the time defined by the Play From control, or simply continue if rendering was faster than real time.
Frame Rate is the default setting for all shortcuts and is recommended for general use.
When Preview Favors is set to Length, After Effects begins playback by rendering and caching frames with only a small advance buffer, at no faster than real-time frame rate. The entire range will preview; if the cache fills available RAM before all frames in the range are rendered, the oldest frames in the cache are discarded. Real-time playback will only occur if the frames render faster than real time, or after the first loop if the entire range fits in the cache.
Length is best used when previewing frames that render faster than real time, which is often the case in the Footage panel, or when previewing a range too long to fit all the frames in the cache.
For both Frame Rate and Length:
- Playback begins immediately, simultaneous with frame rendering and caching.
- Audio plays, if enabled. Also see “mute audio when preview is slower than real time” below.
Defines the range of frames that are previewed:
- Work Area: Only the frames within the work area.
- Work Area Extended by Current Time: This range dynamically extends the work area by the position of the current-time indicator (CTI).
- If the CTI is placed before the work area, the length of the range is from the current time to the work area end point.
- If the CTI is placed after the work area, the length of the range is from the work area start point to the current time; unless From Current Time is enabled, in which case the length of the range is from the work area start point to the last frame of the composition, layer, or footage.
- If the CTI is placed inside the work area, the range is the work area with no extension.
- Entire Duration: All frames of the composition, layer, or footage.
Choose whether to display layer controls for selected layers and other viewer panel overlays during preview. When preview is stopped, layer controls and overlays return to their previous visibility.
Viewer panel overlays include guides, safe margins, grids, and 3D reference axes.
- Off shows no layer controls or overlays during preview.
- Use Current Settings shows the viewer’s layer controls and overlays during preview.
To choose which layer controls to show for the current viewer, open the View Options dialog (View menu > View Options). To choose which overlays to show for the current viewer, open the Choose Grid and Guide Options menu at the bottom of the viewer panel.
While a preview is playing back, you can dynamically show or hide layer controls or overlays by choosing the appropriate option from the View menu or the Choose Grid and Guide Options menu at the bottom of the viewer panel. Layer controls can also be shown or hidden during a preview by pressing the keyboard shortcut: Command + Shift + H (Mac OS) or Control + Shift + H (Windows).
Showing or hiding layer controls during a preview does not affect the state of the Layer Controls option in the Preview panel.
Stop a preview
In previous versions of After Effects, taking almost any action during a preview would stop the preview.
In After Effects CC 2015 (13.5), because you can now make changes to the open project during a preview there are fewer actions that stop a preview. But as in previous versions of After Effects, different preview settings and how the preview is stopped still affect where the CTI is positioned after stop and whether interrupting frame rendering and caching continues playback of the cached frames.
The following actions stop a preview:
- Press any of the preview keyboard shortcuts: Spacebar, Numpad 0, or Shift + Numpad 0.
- Click the Start/Stop button in the Preview panel.
- Choose Composition > Preview > Play Current Preview.
- Press either of the audio preview keyboard shortcuts: Numpad period (.) or Option/Alt + Numpad period (.)
- Press the Esc key.
Some other actions will also cause After Effects to stop a preview. Although not a complete list, here are the most common actions:
- Click into the previewing viewer panel. Clicking the tab of the viewer panel will not stop the preview.
- Adjust a property of time, such as the Work Area bar or Time Navigator bar.
- Drag the current-time indicator (CTI) or click in the time ruler, without the Option (Mac OS) or Alt (Windows) key held down. This action also changes the current time.
- Change the composition settings of a previewing composition.
- Hide the previewing viewer panel behind another panel in the workspace. For example, click a different panel in the same group or open a new viewer panel in the same group.
- Start the render queue.
When a preview stops, two different behaviors are considered:
- If you interrupt the preview before all frames in the range have been rendered, whether to start playback of cached frames before all frames in the range have been rendered. This is only considered when the preview was started with Preview Favors set to Frame Rate.
- Whether the CTI stays at the current time or moves to the playback time (the time at which you stopped the preview).
Most of the above actions stop a preview immediately and not start playback of cached frames, and the CTI stays at the current time.
Pressing the preview keyboard shortcuts (Spacebar, Numpad 0, or Shift + Numpad 0) results in different stop behaviors, depending on which shortcut you press:
- Spacebar: CTI moves to the playback time. If frame rendering is interrupted, playback of the cached frames begins.
- Numpad 0: CTI stays at the current time. If frame rendering is interrupted, playback of the cached frames begins.
- Shift + Numpad 0: CTI stays at the current time. If frame rendering is interrupted, playback of the cached frames begins.
Important: The stop behavior for the preview shortcuts is a result of the shortcut you pressed to stop the preview, not the shortcut you used to start the preview.
Also, remember that the Play/Stop button in the Preview panel and Composition > Preview > Play Current Preview are linked to the shortcut currently displayed in the Preview panel. Using these actions to stop a preview will have the same result as pressing the currently displayed keyboard shortcut.
Mute audio when preview is slower than real time
When the preview frame rate is slower than real time, a new preference allows you to choose whether to mute the audio, or allow it to play.
In previous versions of After Effects, when the preview frame rater was slower than real time, audio would continue to play in real time and thus would slip out of sync. In After Effects CC 2015 (13.5), audio sync is maintained by stuttering the audio.
By default audio does not play during slower-than real-time previews. To enable audio during previews that are slower than real time, open Preferences > Previews and disable Mute Audio When Preview Is Not Real Time. When this option is disabled, audio will stutter when the preview frame rate is slower than real time so that the audio will stay in sync with the video.
You can now choose an open viewer panel or a view (for example, a 3D view) in a panel to always be used for audio and external video preview. This primary view is independent of which viewer or view you are currently previewing and is separate from the viewer or view with Always Preview This View enabled. This is useful when you want a particular composition to always be displayed on your external video monitor while you work in other compositions.
The Primary Viewer button is located next to the Always Preview This View button in the lower left of the Composition, Layer, and Footage viewer panels. Primary Viewer functions similarly to Always Preview This View, except that Primary Viewer only defines which viewer or view is used for audio and external video preview.
Only one view can be set as Primary Viewer; enabling it for a viewer or view will disable it in any other viewer or view where it had previously been enabled.