Objects: Compiling Vertex Array Files; Objects: Preloading; Objects: Normalization - PRG MBOX User Manual

3D Objects: Compiling Vertex Array Files
When Mbox displays a 3D object or digital gobo file onscreen, the file is read from the hard-drive just like 2D content.
Loading object and digital gobo files in their original format (.obj, .svg) and converting them on-the-fly to be used within
the Mbox environment would be a slow process. Instead, Mbox generates a new version of files from the Mbox/Models
folder using a proprietary format. The resulting vertex array (.vtxa) files have been optimized to allow for shorter load
times when the files are requested for display. The process of creating the vertex array files is called "compiling."
All appropriate files in the Models folder will be compiled automatically the first time the Mbox application is launched
and new or modified file are successfully located. Thereafter, existing files in the Models folder need not be recompiled
unless they have been modified since the last time media was rescanned or the Mbox application was launched.
Compiling a large number of files in the Models folder takes some time, but this task only needs to happen once and can
happen in the background, allowing all other functions to run with minimal impact during this process.
If objects or digital gobos are still waiting to be compiled and a layer attempts to display them, Mbox will display a fully-
transparent null image until the requested file has been compiled.
Note: If a large number of new files are placed into the Models folder, they may not be available as soon as the
application launches or immediately after a rescan. But once compiled, the files will be available immediately.
Compiled object files are automatically placed in the /Mbox/model_cache folder. These files are given a numerical prefix
and the .vtxa (vertex array) suffix. These vertex array files cannot be edited or renumbered. Any additions, deletions,
or renumbering of object or digital gobo content should be done using the original versions of the objects in the Models
folder rather than in the model_cache folder.
3D Objects: Preloading
If large, complex 3D objects are used, even being compiled as vertex array files they may not appear on screen as
quickly as desired. To assist, Mbox can be told to preload specific 3D objects into system RAM at startup. In order
to force a file to preload, either append ".preload" to its filename or to the name of its immediate parent folder - which
would cause all of the files in that folder to be preloaded. Examples:
single file - 001.Object.preload.obj entire folder - 002.LargeObjects.preload
Preloading a large number of objects will cause Mbox to take longer to start up and should only be done if the objects
in question do not appear on screen as quickly as desired. When objects are preloaded, it is the vertex array file that is
preloaded rather than the original .obj or .vle file. Because of this, preload time is reduced, but it could take longer than
normal for the application to launch.
3D Objects: Normalization
By default, all object and digital gobo (.svg) files are "normalized" when they are compiled. Mbox's vertex array compiler
performs this task to ensure that files appear at a usable scale rather than being too large or too small. Given the variety
of applications that can be used to create objects and digital gobos, an object that appears to be just right when created
might appear to be gigantic or tiny when displayed by Mbox.
3D modeling applications can be configured to use different units of scale – pixels, inches, meters, etc. – but two objects
that are the same size may be created using different units. An object that is 1m tall and uses millimeters for scale will
be 1000 generic units tall when saved as an .obj file. An identically sized unit that uses feet for scale will be 3.29 generic
units tall. Even though the objects are the same height, when their resulting .obj versions are drastically different heights.
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