& Construction
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Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
& Manufacturing
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Professional CAD/CAM tools built on Inventor and AutoCAD
Transcript
00:02
We can project curves onto a subdivision
00:05
and use the curves-on-surface to divide or split the surfaces.
00:10
I'm just going to work on a section of the hood
00:12
and I'll use the Object Lister here to show how the subdivision structure works.
00:18
So you can see we've got these eight faces here.
00:21
So I'll just do a projection in Z,
00:23
pick the subdiv, do a space bar for Go,
00:26
pick the curves, and space bar to Project.
00:30
So we get the curves-on-surface with history on these two faces
00:34
and they're shown here in the Object Lister.
00:37
So when I Trim, I'll pick the subdiv
00:39
and then I could select here to do a Keep
00:43
or move it over here to do a Discard.
00:46
And in the Object Lister, those two faces are now displayed as trimmed.
00:51
But if I was to Untrim that
00:53
and Trim again
00:55
this time, I can say Divide instead.
00:59
And if I shade that up and have a look over here,
01:02
it's created a second subdivision that's been copied from the first.
01:06
And if I give it a shade of color,
01:08
you can see that it's been trimmed to keep that small region
01:11
and the original has been trimmed with the hole.
01:15
But if I try to display the CVs with the duplicated subdiv, they don't appear.
01:21
And that's because of this H for history.
01:23
So the CVs on this one are driven by the CVs on the original.
01:28
So I can only display the original CVs.
01:31
And that means that if I make a modification,
01:34
both surfaces get changed in exactly the same way,
01:37
which is really useful.
01:40
And also they've both got history with the projecting curves.
01:44
So I can scale that a bit or move it
01:47
and they both stay updated.
01:49
But this duplication has implications when you Untrim.
01:53
So if we changed our minds and decided to pick both of those and do an Untrim,
01:59
you notice here that the copy is a full
02:01
duplicate of the original with all eight faces.
02:04
And if I turn off the original,
02:06
you see that the copied one has lost
02:07
the construction history on the curves-on-surface,
02:11
but it's still there on the original.
02:14
So it's good practice if you do Untrim to be aware that you'll have that duplicate
02:19
and to delete it.
02:23
So now I'm going to have a look at a more complicated example on the roof subdivision
02:27
and create some windscreen details using these curves.
02:31
And I will often take a copy when I'm doing lots of trimming
02:35
to keep a simple version of the subdivision.
02:37
If I want to go back to sculpting the basic form.
02:40
So I've got my subdivision note here
02:43
and I'll just do a Z projection again.
02:47
And that gives me the windscreen outlines on the roof.
02:52
So then when I Trim Divide,
02:54
if I want this main roof part to be the master,
02:57
then I pick the subdivision
02:59
and then I'll only select these regions for the Divide
03:03
but leave this main part of the roof unselected.
03:06
So then when I say Divide, you can see over here that that's been left as the master
03:11
and I've got these four extra copies.
03:14
So I can assign some different shade of colors to make that easier to see.
03:19
And that quickly gives me a lot of detail for visualization
03:22
without having to do all that splitting with subdivision modeling,
03:26
which would be a lot of work and add a lot of complexity to the control cage.
03:31
So then if I want to make a modification, then I can display all the CVs on the master
03:36
and history will probably work quite well with small changes.
03:42
But sometimes you get a trimming issue and you'll have to go
03:45
and do an Untrim and a re-Trim to sort it out.
03:49
And that's one of the main reasons why I'll often keep a basic version
03:52
for when I want to go back to sculpting the subdivision.
00:02
We can project curves onto a subdivision
00:05
and use the curves-on-surface to divide or split the surfaces.
00:10
I'm just going to work on a section of the hood
00:12
and I'll use the Object Lister here to show how the subdivision structure works.
00:18
So you can see we've got these eight faces here.
00:21
So I'll just do a projection in Z,
00:23
pick the subdiv, do a space bar for Go,
00:26
pick the curves, and space bar to Project.
00:30
So we get the curves-on-surface with history on these two faces
00:34
and they're shown here in the Object Lister.
00:37
So when I Trim, I'll pick the subdiv
00:39
and then I could select here to do a Keep
00:43
or move it over here to do a Discard.
00:46
And in the Object Lister, those two faces are now displayed as trimmed.
00:51
But if I was to Untrim that
00:53
and Trim again
00:55
this time, I can say Divide instead.
00:59
And if I shade that up and have a look over here,
01:02
it's created a second subdivision that's been copied from the first.
01:06
And if I give it a shade of color,
01:08
you can see that it's been trimmed to keep that small region
01:11
and the original has been trimmed with the hole.
01:15
But if I try to display the CVs with the duplicated subdiv, they don't appear.
01:21
And that's because of this H for history.
01:23
So the CVs on this one are driven by the CVs on the original.
01:28
So I can only display the original CVs.
01:31
And that means that if I make a modification,
01:34
both surfaces get changed in exactly the same way,
01:37
which is really useful.
01:40
And also they've both got history with the projecting curves.
01:44
So I can scale that a bit or move it
01:47
and they both stay updated.
01:49
But this duplication has implications when you Untrim.
01:53
So if we changed our minds and decided to pick both of those and do an Untrim,
01:59
you notice here that the copy is a full
02:01
duplicate of the original with all eight faces.
02:04
And if I turn off the original,
02:06
you see that the copied one has lost
02:07
the construction history on the curves-on-surface,
02:11
but it's still there on the original.
02:14
So it's good practice if you do Untrim to be aware that you'll have that duplicate
02:19
and to delete it.
02:23
So now I'm going to have a look at a more complicated example on the roof subdivision
02:27
and create some windscreen details using these curves.
02:31
And I will often take a copy when I'm doing lots of trimming
02:35
to keep a simple version of the subdivision.
02:37
If I want to go back to sculpting the basic form.
02:40
So I've got my subdivision note here
02:43
and I'll just do a Z projection again.
02:47
And that gives me the windscreen outlines on the roof.
02:52
So then when I Trim Divide,
02:54
if I want this main roof part to be the master,
02:57
then I pick the subdivision
02:59
and then I'll only select these regions for the Divide
03:03
but leave this main part of the roof unselected.
03:06
So then when I say Divide, you can see over here that that's been left as the master
03:11
and I've got these four extra copies.
03:14
So I can assign some different shade of colors to make that easier to see.
03:19
And that quickly gives me a lot of detail for visualization
03:22
without having to do all that splitting with subdivision modeling,
03:26
which would be a lot of work and add a lot of complexity to the control cage.
03:31
So then if I want to make a modification, then I can display all the CVs on the master
03:36
and history will probably work quite well with small changes.
03:42
But sometimes you get a trimming issue and you'll have to go
03:45
and do an Untrim and a re-Trim to sort it out.
03:49
And that's one of the main reasons why I'll often keep a basic version
03:52
for when I want to go back to sculpting the subdivision.
Required for course completion