& 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
Retopo is a tool set that uses the mouse buttons and the Shift, Ctrl and Alt keys
00:07
to provide the same functions as these subdivision build and edit tools.
00:12
And it's similar to Maya's Quad Draw
00:13
in that you can build on to target meshes
00:16
or NURBS surfaces
00:18
or onto a view plane.
00:21
I'm going to use this mesh as a target.
00:24
But first, I'll just make it a bit more transparent so I can use it as an underlay.
00:28
Then I can double-click on the
00:30
Retopo tool
00:31
and make sure that I've got history turned on
00:34
and the first prompt is for the target.
00:37
So I'll use this body side and hit Next or space bar.
00:41
And the second prompt is for projecting an existing SubD, but I haven't got one,
00:45
so I'll go straight to the Go button
00:47
or space bar again.
00:49
So then I get this hotkey help card here which shows all the tools I can use.
00:55
And so I start by placing some dots on the mesh roughly where I want the vertices to be.
01:02
And you can see that they've been placed directly onto the mesh.
01:07
And then if I hold the Shift key down,
01:09
I get a preview of the possible quads and then I just click to build the ones I want.
01:15
And then I could do more dots.
01:17
Or this time I can use the Shift key to extrude edges by clicking and dragging.
01:22
And then without the Shift key, I can adjust a vertex
01:26
or an edge or even a face.
01:31
When I have a longer edge loop,
01:33
then Shift with the left mouse button
01:35
extrudes just one edge.
01:37
So I'll do another one of those.
01:42
And then Shift with the middle mouse button extrudes a whole edge loop.
01:46
So without Shift, I can tidy those vertices a bit.
01:51
And then to finish off the topology down here, I could either extrude one face
01:57
and then the Shift button shows me this preview
01:59
and I can click to bridge across the gap
02:02
or if I undo that,
02:04
then I could extrude the whole edge loop with the middle mouse button.
02:08
And then I have this gap here.
02:10
But all I need to do is just drag one
02:12
point on top of another and they're automatically welded.
02:16
So I'll come out of the
02:17
Retopo tool using Pick Nothing, Pick Object
02:20
and I'll put some cross sections on.
02:22
So you can see that the limit surfaces
02:24
in green are sitting slightly below the target mesh
02:26
because they're always slightly inwards of the control cage vertices.
02:33
And I've come out of Retopo
02:34
now, so I need to do a Query Edit History to get back into that editing mode.
02:40
So the Shift key on an interior edge loop does a perpendicular insert,
02:45
so I can add some loops to bring that close to the mesh
02:50
and I can continue to extrude around the wheel arch.
02:53
But I also want to follow this belt line.
02:57
And so to change that topology, I could use Ctrl and
03:00
Alt to cut from that point here
03:02
across to here.
03:05
And then I can just use the Ctrl key to delete that triangle.
03:09
But any time I can click additional dots
03:12
and then use one of those to create another face with the Shift key.
03:18
And then I'll just do some extrudes to finish off around the wheel arch
03:22
and continue along the belt line.
03:26
And then finally holding and moving the right mouse button
03:29
is a Relax function that eases out the angles between all the edges
03:33
and lets me tidy up the SubD.
03:39
And finally,
03:39
I'm going to use these three examples to
03:41
look at the History and Projection settings.
03:44
This one has both selected.
03:46
So if I move a vertex when I'm outside the
03:49
Retopo tool,
03:50
then as soon as I let go of the mouse, it always snaps back to the target geometry.
03:56
Without Persistent Projection,
03:57
then I'm free to move any vertices away from the target.
04:01
But when I next use Query Edit,
04:03
then I can move any of the other vertices and that one's not affected.
04:08
But as soon as I touch that one,
04:09
it will get re-projected onto the target.
04:13
Then finally, with no history at all, then obviously
04:16
I'm free to move any of the vertices,
04:18
but I've got no way back into the Retopo
04:21
tool using Query Edit.
04:23
And instead I just need to use the standard SubD tools to keep working on it.
00:02
Retopo is a tool set that uses the mouse buttons and the Shift, Ctrl and Alt keys
00:07
to provide the same functions as these subdivision build and edit tools.
00:12
And it's similar to Maya's Quad Draw
00:13
in that you can build on to target meshes
00:16
or NURBS surfaces
00:18
or onto a view plane.
00:21
I'm going to use this mesh as a target.
00:24
But first, I'll just make it a bit more transparent so I can use it as an underlay.
00:28
Then I can double-click on the
00:30
Retopo tool
00:31
and make sure that I've got history turned on
00:34
and the first prompt is for the target.
00:37
So I'll use this body side and hit Next or space bar.
00:41
And the second prompt is for projecting an existing SubD, but I haven't got one,
00:45
so I'll go straight to the Go button
00:47
or space bar again.
00:49
So then I get this hotkey help card here which shows all the tools I can use.
00:55
And so I start by placing some dots on the mesh roughly where I want the vertices to be.
01:02
And you can see that they've been placed directly onto the mesh.
01:07
And then if I hold the Shift key down,
01:09
I get a preview of the possible quads and then I just click to build the ones I want.
01:15
And then I could do more dots.
01:17
Or this time I can use the Shift key to extrude edges by clicking and dragging.
01:22
And then without the Shift key, I can adjust a vertex
01:26
or an edge or even a face.
01:31
When I have a longer edge loop,
01:33
then Shift with the left mouse button
01:35
extrudes just one edge.
01:37
So I'll do another one of those.
01:42
And then Shift with the middle mouse button extrudes a whole edge loop.
01:46
So without Shift, I can tidy those vertices a bit.
01:51
And then to finish off the topology down here, I could either extrude one face
01:57
and then the Shift button shows me this preview
01:59
and I can click to bridge across the gap
02:02
or if I undo that,
02:04
then I could extrude the whole edge loop with the middle mouse button.
02:08
And then I have this gap here.
02:10
But all I need to do is just drag one
02:12
point on top of another and they're automatically welded.
02:16
So I'll come out of the
02:17
Retopo tool using Pick Nothing, Pick Object
02:20
and I'll put some cross sections on.
02:22
So you can see that the limit surfaces
02:24
in green are sitting slightly below the target mesh
02:26
because they're always slightly inwards of the control cage vertices.
02:33
And I've come out of Retopo
02:34
now, so I need to do a Query Edit History to get back into that editing mode.
02:40
So the Shift key on an interior edge loop does a perpendicular insert,
02:45
so I can add some loops to bring that close to the mesh
02:50
and I can continue to extrude around the wheel arch.
02:53
But I also want to follow this belt line.
02:57
And so to change that topology, I could use Ctrl and
03:00
Alt to cut from that point here
03:02
across to here.
03:05
And then I can just use the Ctrl key to delete that triangle.
03:09
But any time I can click additional dots
03:12
and then use one of those to create another face with the Shift key.
03:18
And then I'll just do some extrudes to finish off around the wheel arch
03:22
and continue along the belt line.
03:26
And then finally holding and moving the right mouse button
03:29
is a Relax function that eases out the angles between all the edges
03:33
and lets me tidy up the SubD.
03:39
And finally,
03:39
I'm going to use these three examples to
03:41
look at the History and Projection settings.
03:44
This one has both selected.
03:46
So if I move a vertex when I'm outside the
03:49
Retopo tool,
03:50
then as soon as I let go of the mouse, it always snaps back to the target geometry.
03:56
Without Persistent Projection,
03:57
then I'm free to move any vertices away from the target.
04:01
But when I next use Query Edit,
04:03
then I can move any of the other vertices and that one's not affected.
04:08
But as soon as I touch that one,
04:09
it will get re-projected onto the target.
04:13
Then finally, with no history at all, then obviously
04:16
I'm free to move any of the vertices,
04:18
but I've got no way back into the Retopo
04:21
tool using Query Edit.
04:23
And instead I just need to use the standard SubD tools to keep working on it.
Required for course completion