3D Flipbook

December 8th, 2005 by Brent McPherson - Viewed 12675 times -




The flipbook is a pretty important tool in XSI for evaluating animation. However, there is another way to playback animation in real-time that you may not know about. Ever wonder what the fast playback option in the display menu does?

Think of fast playback as a 3D flipbook. Instead of capturing images it captures the visible geometry per frame and then blasts it back at full speed to the graphics card after all the frames have been captured. You gain a speed advantage over the regular flipbook because it is not writing and reading frames to/from the hard disk. You can also zoom, orbit and pan the camera during playback which is helpful when trying to evaluate animation.

In order to use fast playback there are some things that need to be setup first…

First, you need to turn on the option under Preferences > Interaction to limit the maximum playback rate to the scene rate. Otherwise, fast playback will be much too fast.

Next, it is a good idea to turn off scene/selected display stats if you have them turned on since they will cause XSI to evaluate geometry and defeat the purpose of fast playback. It is also a good idea to turn on the fast playback cache size display in the same property page.

Finally, maximize or solo the 3D viewport you want to playback, turn on fast playback in the display menu, turn on looping, make sure playback is set to play all frames and hit the playback button. The first time playing through the geometry will be cached and after that fast playback will kick in.

The most important thing to note about fast playback is that the cache must be cleared manually to see the results of any changes you make. Then easiest way to do this is to toggle fast playback off and on again in the display menu. Alternatively you can use the clear button under Display Options > Performance.

Ok, now that the fun part is over I’ll fill you in on what the other fast playback options do…

Camera Display

First and foremost is the cache size per frame. If some of your geometry is not showing up or you get a cache overflow message you need to increase this number. By default fast playback will use the current display mode when playing back so in shaded mode you will see shaded geometry. (Note: it does not support textured display though)

To reduce the memory per frame you can enable wireframe capture. There are two flavors of wireframe capture depending on whether the 3D cache option is enabled. If it is enabled then 3D wireframe data is stored. If not, then 2D wireframe data is cached. 2D wireframe data is stored in a packed format that uses about a third the memory of 3D wireframes. (and 3D wireframes usually use less than half the memory of shaded geometry) However, the memory savings from 2D wireframe caching comes at a price since you lose the ability to manipulate the camera during playback when using 2D wireframe capture.

6 Responses to “3D Flipbook”

  1. fouad says:

    hi there!
    great blog.. btw

    i was wondering tho.. about this 3d flipbook business.. i cant get it to work.
    after i follow all your instructions, i hit play and i get a “cache overflow” message at the bottom of the screen. the viewport goes blank, and after the caching run is over, when i hit play, theres nothign on screen but a few weird artifacts.

    is this a video card problem? or is my scene too heavy perhaps?

    thanks for your time!

  2. fouad says:

    ah.. and ive been upping the cache size to no avail

  3. I would suggest reading the last two paragraphs again. Have you increased the “Cache Size” slider and/or switched to wireframe caching to save memory?

  4. fouad says:

    hah! ok hid everythign in the scene except waht was important.

    and it works

    nice!

  5. Mike Stramba says:

    Brent,

    Thx very much for the detailed steps on fast playback.

    It works great, although I have to wonder why all of these steps aren”t just incorporated “under the hood” of the “real time” playback option.

    Mike

  6. Yes, many of these things should be done automatically. We really haven”t enhanced this area too much since it was initially implemented in XSI.

    Until I wrote this blog I didn”t realize that so many users were unfamiliar with this feature so perhaps we will have more incentive to make this more automatic in the future. Sometimes when we don”t get comments or requests for a particular feature we just assume users are happy with it. ;-)

    Of course, I can”t comment on future development plans and priorities and we may also decide to concentrate our development efforts elsewhere in future XSI versions.