- [Instructor] Next I want to talk about
fit to geometry and control points.
What fit to geometry allows me to do is pick a surface
and some targets, in this case it's a mesh.
This mesh is off of a clay scan.
Somebody modeled up a clay part,
scanned it in and brought it in.
Because the scan has tool marks that could be a little rough
we're going to surface over the top of that scan.
That scan is our reference to design up to.
So we're going to take that surface
and project it up to that scan.
Once I have those objects selected,
these targets could also be curves,
it doesn't have to be a scan, I'm going to say fit
and as you can see it takes that surface
and pushes it up to that scan.
You're going to see some variations in distance and deviations
off of the original scan which is what you want.
There may be a tolerance involved,
maybe a quarter of mil, half a mil, an entire millimeter
or more depending on the quality of the scan
as well as how tight you need to hold to that scan.
And with that, I have the ability to increase
or decrease the amount of math, the NURBS math,
by right mouse clicking on one of those little flags
and then reimposing the surface onto that mesh.
If I just simply click on that number,
you can see it just goes up and refit it.
So I may be getting closer, pushing it further away,
creating undulating surfaces, so it's kind of a dance
between what you want to do and what the system wants to do.
So you have to find that nice medium,
some place where the surface is very simple,
as simple as it can be, but really close to the mesh
without absorbing any of the flaws of the mesh.
Once I get it close to what I want,
I select okay and you'll note that there's no history here.
And then I can go into control points.
With the control points, I specify my surface.
The support here is the direction in which
I can move those control points.
More often than not, you're going to use something
like local normals along mesh lines or normal to compass,
so there are plenty of other ways to move these around,
but for the most part generally speaking,
normal to compass, mesh lines and local normals.
In this case if I say mesh lines and what do I want to move?
One of the control vertices or the entire hull or the mesh?
Now when I pick on that mesh you can see
it's the entire row, not just one of those points.
And I'm causing a swinging deviation
back to that original mesh.
If I want to move just one of those points
I can pick a point right over here.
Pick the point that I want and as you can see
I'm moving just a singular point.
We can do the same thing up here
and I'm moving just that singular point.
I also have the ability to go local normals
and with this, singular point is specified
so only the one point will move.
If I want to move the entire row I come back in,
specify mesh only, now it's the entire row.
If I pick this row here you can see it highlights it orange
and now I'm able to move that entire row.
This is just a combination of points and mesh
so you don't have to toggle back and forth.
If I want to move along a compass direction,
the compass direction is the Z of the compass,
so you're going to have to, again, right mouse click
and change the orientation of said compass
or drag it and drop it and put it onto something
that defines the direction you want to move.
Again, it's the Z direction of the compass
that the mesh will move in.
So now if I grab the mesh it'll move in the Z direction.
If I have a bumpy mesh or I'd done something
and I want to smooth the mesh out
and let the system do the work for me,
I can come in here and do something called harmonize
and what this will do is it'll harmonize
those control points, sort of smooth everything out
a little bit and take you back to more
of a neutral or a cleaned up mesh and then I can go back in
and begin manipulating those control points as I see fit.
So if I wanted to move, again, local normals
and start moving those around.
So, again this allows you to tweak or manipulate
that surface to get it to the shape that you need.