Build subdivisions with Retopo

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.

Video 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.

Video quiz

Required for course completion

If you want the ability to leave the Retopo tool and then return by selecting Query Edit History, which of the following options needs to be selected when you start using the tool?

(Select one)
Select an answer

1/1 questions left unanswered

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