- [Instructor] Now I wanna talk about
a tool called Offset Surface.
So we're gonna go into the Surface tab.
We're gonna go find Offset Surface.
Now with Offset Surface, you're basically taking
either it can be one face or an entire surface
like in this case, I want this entire body.
So I'm just gonna change this to Body Faces.
Remember selection intent.
And it's gonna offset those surfaces
based off of the surface normals.
So in this case, I just reverse that
so we can see the full chain here.
I have a constant gap between the original surface
and that offset surface.
So it's basing everything off of the surface normals.
Now offset surfaces are very powerful,
extremely powerful tool, I use it all the time.
But as a warning to you,
it can add a lot of mass to your part file,
which means it can make your part file or data massive.
So based off of what you're doing
and the amount of math that's in there,
it could easily add a ton to the file size at the end of it.
So, just warning to you so you know
kinda what's going on there.
So, with that, I can just do my offset distance
based off of the surface normals.
Now if I reverse this, what I want you to notice
is if a blended area or a filleted area like that
goes off into zero,
as you can see here, just forms a nice crisp, sharp edge.
So in a lot of cases when you're doing offsets
that are greater than the radius of a surface,
it'll wash 'em out.
Like in this case it's pretty easy for it to wash out.
It's a fairly predictable shape, it'll wash it out.
The issue comes in when you have
a large face chain, you have extremely heavy surfaces
and then you have surfaces that are switching
from positive to negative curvature,
then you may end up with offsets that don't wanna happen.
Let me go ahead and close this.
For the most part, you have the ability
to wash away those corners.
And that's part of the reason why the offset surfaces
tend to be very heavy is 'cause it really is
a lot of math going on underneath it all.
So if I come down here,
now I'm just gonna select OK.
You can see there's my offset surface.
If I reverse this, once again, there's my offset surface.
So I'm gonna undo that, go back to start.
I'm gonna do my offset surface again,
Body Faces, pick my body faces.
This time what I'm going to do is I'm gonna change
my output from One Feature for All Faces,
this is what is basically driving everything right now,
to be one big singular offset surface.
And I can change this to One Feature for Each Face.
Now when I do that, what ends up happening in this case
is it throws up a warning.
I can still create the offset surfaces,
but what it's going to do is it's gonna create
a separate feature for each one of those faces
as it does the offset.
And this is warning me that there is a face
in that face chain that cannot be offset.
That makes it kind of obvious which one it is.
So it's telling me that that does not exist in the offset
and because it does not exist in the offset
as the offset is right now,
it will not make a feature for that face.
So if I select OK, you'll see I have Offset Surface,
Offset Surface and it is now just a simple direct offset
from this face to this face.
If I try to modify this, you'll notice that
it's just simply doing a single face offset.
Even though I picked the entire body,
that setting, when I went in there
and made that change to say offset,
each one has its own separate feature,
it automatically switches to what it can offset,
turns off the selection intent,
and just picks the single face.
So occasionally you may need to do something like that.
I find it kind of useful if I'm doing the B side,
let's say a plastic part.
I have a very nice highly stylized surface
and I need to offset that in a few millimeters,
maybe I have some small radii
and then I just pick the whole A side offset to the B side
and then I go back in and apply
the blends and fillets that I need.
I may have varying thicknesses
or I may have a much larger blend on the back side
for strength purposes or material flow purposes,
whatever that may be.
So in this case, I have separate,
as you can see, offset surfaces,
it separated them out from the one feature.
So I'm gonna delete these, just pick 'em, delete 'em.
I'm gonna go back into Offset Surface.
You'll notice that when I go back in there,
the selection intent goes back to the original,
the Body Faces.
So here I can pick it.
Now if I do my reverse, that error goes away
because now it can actually do the offset
on that surface because it's no longer washing it out,
I don't get that message and everything's fine.
And again now, I have the ability at this point
to switch this from One Feature for All Faces.
I get back some partial results.
This is only available when I'm doing partial results.
Basically I'm creating a big long
face chain of these offsets, which you'll see here again.
And if there's the offset issues, again,
if I reverse, this is a partial result
'cause it's washing out that corner,
I select OK.
Again, there's my offset surface
without that corner.
If I reverse that, I get that corner back
and everything works just fine.
You'll also notice that now it's created,
I can't go back and change that offset type
to be one offset per face.
So once it's created,
that's one of those things you can't go back and modify.
It just locks it down.
It's the entire body in this case
or in the other case it would've been singular offsets.