- [Instructor] When working with symmetry,
it's a best practice to make sure that all of the vertices
on the seam are exactly aligned with the reflection plane,
and that will avoid any problems such as
what we're seeing here.
We got a gap in the model.
In the previous movie, we moved some points around
using sub-object constraints and that introduced
a little bit of error into the alignment
of those vertices along the seam.
I've just got a version of that scene here
in which I've really exaggerated the problem.
So it'll be quite clear what's going on.
So we want to be able to see all the individual points.
There's an easy way to correct this issue provided that
the object is positioned at the origin or in this case,
the seam, or the reflection plane is aligned
with the X value of 0.
So I've positioned my object here in the center of the world
for this reason because it's going to be really easy
for me to send all of those border points
or the points along the seam back to where they need to be,
which is at an X value of 0.
I'll select that cushion and let's isolate it,
Control + Alt + Q.
Go into Modify Mode in the ribbon.
And we need to go down a couple levels.
Previous Modifier, click that a couple times.
So we're at the level of the editable poly,
and you see that I've got a bunch of points
that are not aligned with the seam.
I want to send all those to an X position of 0.
And there are complicated ways
of doing that using the scale tool and using different
reference coordinate systems and transform centers.
But there's actually a really easy way to do this
directly from within the modeling ribbon.
Provided that the object is aligned as I have it here
with the reflection seam exactly aligned
with one of the major axis of the world.
We can select all the points on that seam
by using border sub-object mode.
We haven't seen that before.
Let's go into border sub-object mode
And a border is a selection of edges that only have
a polygon on one side.
And that border got automatically selected.
If it's not selected for you, you can just click on it,
and now that border is selected.
And we don't need to be in any transform tool,
we can just be in Select Object.
In order to move all the points on that border
to an X value of 0,
we can use the align tools here on the ribbon.
And what we want to do is use the To View option.
That will move all the selected sub-objects
to the current construction plane
in the currently active viewport.
And that means in this case,
it's going to be one of the side views.
I've got a left view over here.
I'll right click in that view so I don't lose
my border selection, and simply click To View.
And that will snap all those points to an X value of 0.
We've sent them all to the construction plane
of the left viewport, which is the Y,Z plane of the world,
which is located at an X position of 0.
And it was simple as that.
Super easy.
So we can exit out of sub-object mode.
We can go back up to the top of our stack and unhide all
the other objects.
Let's exit isolation, Control + Alt + Q.
All right, very cool.
That's how we can easily move all of the points
on a symmetrical object's border back to
the reflection plane, which in this case,
was the Y,Z plane of the world or an X value of 0.