- [Instructor] One of the best practices
in 3D graphics or really any computer project is versioning.
That simply means saving out many versions of a file.
It's an insurance policy in case something goes wrong.
And in 3D graphics, things go wrong all the time.
If you just use the save command in a computer program,
you're up to the existing file.
In other words, you're overriding the data
in that file with new data.
And when you do that,
you don't have an earlier version to go back to.
That often means that you cannot revert any changes
that you've made, that in turn means you
may have to waste a lot of time attempting
to manually get back to an earlier state.
For my own projects,
it's not unusual at all for me to have 100
or more versions of the same thing.
That might sound excessive, but it's really not.
If I save a new version every 10 minutes,
and make backups at the end of every workday,
then I will never lose more than 10 minutes worth of work.
That is critical in a production environment.
We simply can't afford to waste time.
So versioning is a necessary practice that can't be avoided.
The downside of versioning is
that it tends to use up a lot of disk space.
One way to conserve space and increase flexibility
in your 3D pipeline is to use external references,
What 3dsmax calls Xrefs.
An external reference is a link
to another asset such as a 3D model.
Unlike importing or merging a scene,
an Xref does not encapsulate the incoming data
within the current primary scene.
It just creates a link to an external scene file.
And that scene file gets loaded with the primary scene.
Therefore, when you save a new version
of your primary scene,
its file size is not substantially increased.
External references are a way to minimize the disk footprint
of a project, and they also make it easier
for you to do things like load and unload models
to improve the performance interactively in the view ports.
Or maybe Xrefs would allow you
to swap out different versions of the external file.
XrefS are quite handy,
and especially if you're building architectural
or environmental scenes retake.
Xrefs are quite handy, and especially,
if you're building architectural or environmental scenes,
you're probably going to be working with Xrefs quite a lot.
A good example of effective use
of Xrefs is a model of some grape vines
that I've created for the courtyard scene.
I've got a layout scene here in my current project.
Scroll down here and I'll show you.
It's called 0315 create Xref.
That's going to be the primary scene
for the following movie.
I've also created a sub folder called Xrefs
in my current scenes folder.
Inside that Xref's folder I've got a bunch
of stuff including a file called Vines Xref.max.
And take a look at the size of this,
it's almost 130 megabytes in size.
But if we go back into the scenes folder,
we'll see that the primary scene is less
than five megabytes in size.
So by referencing that vines file into this primary scene,
I will add the vine geometry to the scene
without significantly increasing the disk usage.
So that's an introduction to how Xrefs are going to work,
how they can help you save disk space,
and increase flexibility in your 3D pipeline.
In the following movie, we'll see
how to load Xrefs into max.