Playing Back All Frames or Playing in Real Time
XSI can play all frames of an animation or it can play the animation in real time. It accomplishes real-time playback by choosing the frames to display based on the elapsed time.
For instance, if it takes half a second to display the first frame in a 24 fps animation, frames 2 through 12 will be skipped and frame 13 is displayed next. In other words, when it comes time to display a frame, the frame that should be shown at that moment is displayed.
To play back all frames
To see all the frames in your animation (though not necessarily in real-time), do one of the following:
• Choose Playback > Play All Frames.
or
• Toggle the All/RT
button to All.
To play back frames in real time
Do one of the following:
• Choose Playback > Real-Time Playback.
or
• Toggle the All/RT
button to RT.
or
• Press Shift+up-arrow key.
Setting the Realtime Playback Rate
The frame rate determines how smoothly the animation plays back. You can set the realtime playback rate to whatever percentage you like.
To set a rate preference for realtime playback
1. Do either of the following:
- Choose Playback > Playback/Audio Preferences from the playback panel at the bottom of the XSI window.
or
- Choose File > Preferences from the main menu. In the Preferences explorer that opens, select Interaction or click its icon.
2. On the Playback and Audio tab, set the Realtime Playback > User Rate % to any positive value. 100% is full speed, while 50% is half speed, 200% is double speed, and so on.
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The User Rate % slider goes only to 200 but you can enter values higher than that. |
To select a predefined realtime playback rate
• In the Playback menu, you can quickly select predefined realtime playback speed: 75%, 50%, or 25%. These options are available only when realtime playback is active.
When you do this, the User Rate % value in the Interaction preferences property editor is updated to match what you have selected.
Using Fast Playback with Realtime Playback
You may want to use the Fast Playback option in conjunction with real-time playback to speed up the frame rate. The Fast Playback option caches the raw geometry of objects at each frame the first time you play an animation, then plays it back as quickly as possible. This allows XSI to achieve very fast playback rates, which can help you evaluate an animation’s motion and timing more accurately.
Fast playback is different from capturing images in the viewport (see Capturing Animation in a Viewport (Flipbook)), which stores an image at each frame.
To activate and set up fast playback
1. Do either of the following to activate fast playback:
- Select Fast Playback from the Display Type menu in a viewport.
or
- Choose Display Options from the Display Type menu to open the Display Options property editor. Click the Performance tab and select the Fast Playback option.
2. Set the Fast Playback options on the Performance page.
- If you select Wireframe Capture Only, you can select Use 3D Cache. 3D caching stores extra depth information for the captured geometry so that you can orbit, pan, and zoom the camera during playback. 2D caching (when Use 3D Cache is not selected) stores the data in a more compact form to save memory.
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Fast playback captures only the visible geometry, so if the camera is zoomed out when you play back a 3D cache, the geometry that was outside the view at the time of capture is not visible. |
- Set the Cache Size value, which is the amount of RAM allocated per frame when caching images.
When you have Fast Playback on, you may get a “cache overflow” message. Make sure to either deselect Fast Playback or increase the Cache Size.
3. Play the animation.
The first time you play the animation, each frame is cached. When you play back the animation again, it is played as quickly as possible.
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If you change the animation after you cache it, the cache will not be updated automatically. You must deactivate and then reactivate the Fast Playback option to accommodate the changes, or click the Clear button on the Performance property page to clear the cache. |
Setting the Playback Speed Limit
Sometimes things can go just a little too fast. For example, when playing back all frames, it is not really useful to have the animation play back faster than the set frame rate, or you want to play all frames to cache them, but the playback is too fast. Luckily, there is a simple remedy for limiting the playback speed to the scene’s current frame rate.
To prevent all frames from playing back too quickly
1. Do either of the following:
- Choose Playback > Playback/Audio Preferences from the Playback panel.
or
- Choose File > Preferences from the main menu. In the Preferences explorer that opens, select Interaction or click its icon.
2. Select the Limit Max Playback Rate to Scene Frame Rate option on the Playback and Audio page.
This prevents the All Frames playback option (see previous page) from playing back faster than the scene’s playback frame rate.
SOFTIMAGE|XSI v.6.01