Select an object. > Modify panel > Modifier List > Object-Space Modifiers > Unwrap UVW
Select an object. > Modifiers menu > UV Coordinates > Unwrap UVW
The Unwrap UVW modifier is used to assign planar maps to sub-object selections, and to edit the UVW coordinates of those selections. Existing UVW coordinates on an object can be unwrapped and edited as well. Maps can be adjusted to the proper fit on a Mesh, Patch, Polygon, HSDS, or NURBS model.
The Unwrap UVW modifier can be used as a self-contained UVW mapper and UVW coordinate editor, or in conjunction with the UVW Map modifier. If you use Unwrap UVW in conjunction with the UVW Map modifier, it is usually so you can map the model with a method other than planar mapping, such as cylindrical or spherical mapping. You can animate UVW coordinates by turning on the Auto Key button and transforming the coordinates at different frames.
Note: After applying the Unwrap UVW modifier, open mapping edges, or seams, appear on the modified object in the viewports. This helps you visualize the locations of mapping clusters on the object surface. You can toggle this feature and set the line thickness with the Display setting.
Rather than creating a large modifier stack by first making a sub-object selection of faces and then adding a UVW Map modifier to specify the type of mapping, you can use the Unwrap UVW modifier to do both. You can select sub-object vertices, edges, or faces/patches, store sub-object selections as named selections, map them using the planar method, and then edit the UVW coordinates for each sub-object selection, all from within the Unwrap UVW modifier. For example, to map a character's face using three planar maps, you could create three sub-object selections of the front and sides of the face, planar-map the selections individually, and then edit the UVW coordinates for each selection, all without leaving the Unwrap UVW modifier.
When you apply the Unwrap UVW modifier, it stores the object's current mapping coordinates in the modifier. If the object has no mapping coordinates, the modifier creates new ones by applying planar mapping. If the incoming data on the stack is a face-level or polygon-level sub-object selection, then only the UVWs for the selected faces are brought into the modifier, and the modifier's sub-object levels are unavailable.
When the modifier is evaluated, its UVWs are reassigned to the object flowing down the pipeline. So if the UVWs upstream are changed, the changes won't make it past the Unwrap UVW modifier. If the Unwrap modifier is operating on a selection of faces, then upstream changes to unselected faces will still be able to flow past the Unwrap modifier.
Unwrap UVW supports polygon faces and Bezier quad and tri patch faces in addition to triangles and quads.
Below is a sample of what the various face types look like based on the incoming type. For HSDS and Poly surfaces, the basic interface remains the same, except that the maximum number of sides per polygon increases from 4 to over two billion. HSDS supports only one level of detail: the level at which the mapping was. Patches have handles on nonlinear vertices. These handles work just like regular patch handles.
To use Unwrap UVW:
This is a general overview of using the basic Unwrap UVW tools available on the Modify panel and the Edit UVWs dialog. Unwrap UVW provides many additional tools, particularly in the editor.
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Apply the modifier and a texture-mapped material to an object. Set the material to display in the viewports, set at least one viewport to be shaded (e.g., press F3 to toggle between Wireframe and Smooth+Highlights), and, if necessary, turn off Shade Selected Faces (press F2) for that viewport so the texture mapping is visible.
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Go to the Face sub-object level of the Unwrap modifier and make a selection of contiguous faces. You'll use a single mapping type on this selection.
Within the single modifier, you can apply as many different mappings as you like to different face selections.
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It is recommended that you name the selection using the Named Selection Sets function on the main toolbar. This makes it easy to return to the selection set in the viewports for subsequent mapping adjustments. For example, if you're working on a house, you could use names such as roof.
Important: Be sure to press Enter after typing the selection set name.
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On the Map Parameters rollout, click the Planar button and then adjust the gizmo using any combination of the transform tools (Move, Rotate, Scale) in the viewports and the Align buttons (Align X, etc.) on the Map Parameters rollout.
Tip: You can often save time by starting with the Best Align command and then adjusting manually from there.
After each adjustment of the mapping gizmo, the texture display in the viewports updates to reflect the mapping changes, as do the green seam lines on the object that show where the open edges lie (depending on the object shape and mapping type; the seam lines don't change with Planar mapping). To cause the viewports to update in real time, turn on Edit UVWs dialog > Constant Update.
You can also open the editor (Parameters rollout > Edit) to view the changes in the generated texture coordinates as you adjust the gizmo.
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Click the Planar button again to turn it off and exit mapping for this face selection.
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Continue making and naming selections and applying mapping until the entire mesh is mapped. Use the green seam display lines as a guide. If you don't see them, make sure Parameters rollout > Display Group > Thin Seam Display or Thick Seam Display is active.
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Open the Edit UVWs dialog (Parameters rollout > Edit).
By default, the editor displays a checkered background. To view the map in the material on the object, you need to change a setting.
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At the right end of the editor upper toolbar, click the drop-down list that currently reads CheckerPattern (Checker) and choose the map that's applied to the material.
The map appears as the background.
By default, all the UVW clusters display. To work on one cluster at a time, you need to filter the UVWs.
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On the Edit UVWs dialog > lower toolbar, click Filter Selected Faces.
At this point, only faces you select in the viewport will appear in the editor. You can select them directly, or choose a named selection set. In the next step, you'll use the latter method.
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On the main toolbar, open the Named Selection Sets drop-down list, and choose one of your named selection sets.
The viewports show the selection as active, and the UVW coordinates for the selection appear in Edit UVWs window.
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In the Edit UVWs window, select and move a UVW face.
In the viewports, the texture slides around the selected portion of the object mesh.
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Choose a different selection set and edit its UVW coordinates.
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In a viewport, drag to select a group of faces by region.
The faces' UVW coordinates display in the Edit UVWs window. This is another way of choosing what you want to work on.
As you can see, from within the Unwrap UVW modifier you can assign multiple mapping types to different, named face selections, and then edit the UVW coordinates to fine-tune map placement on the geometry.
After applying the modifier, its panel appears, consisting of the modifier stack plus two rollouts:
Normally, when you apply Unwrap UVW to an object, the modifier stack provides access to Vertex, Edge, and Face sub-object levels. These are synchronized with the corresponding selection modes on the Edit UVWs dialog. The Vertex and Edge sub-object levels are useful for making UVW vertex and edge selections in the viewports, where texture mapping on the object surface is more readily visible, and the Edge level is also useful for setting up edge selections.
If you apply Unwrap UVW to an active face selection of an Editable/Edit Mesh/Poly object, or to an active patch selection of an Editable/Edit Patch object, no sub-object levels are available in the Unwrap UVW modifier. You can use Unwrap UVW to edit only the selection that was active when you applied the modifier. Changing the sub-object selection in the object doesn't affect the Unwrap modifier contents, because the modifier obtains the face selection when you first apply it.
All three sub-object levels are synchronized between the modifier stack and the Selection Modes group on the Edit UVWs dialog. When you activate a sub-object level in one, it's also activated in the other. Similarly, selecting sub-objects in a viewport selects them in the editor and vice-versa.
Use these settings to make or modify a sub-object selection for use by the modifier. If you've passed a face selection up the stack, for example from the Poly Select modifier, Unwrap UVW uses that instead, and makes these controls unavailable.
+ button—Expands the selection by selecting all faces adjacent to selected faces.
- button—Reduces the selection by deselecting all faces adjacent to non-selected faces.
Ring—Expands an edge selection by selecting all edges parallel to the selected edges. Ring applies only to edge selections.
Loop—Expands the selection as far as possible, in alignment with selected edges. Loop applies only to edge selections, and propagates only through junctions of even numbers of edges.
Ignore Backfacing—When region selecting, prevents the selection of faces not visible in the viewport.
Select By Element—Lets you select elements.
Planar Angle—Lets you select contiguous coplanar faces with one click. Turn this on, and then set the threshold angle value that determines which faces are coplanar. Then click a face to select it and all contiguous faces whose angles are less than the threshold value.
Planar Angle is available only at the Face sub-object level.
Select MatID—Enables face selection by material ID. Specify the material ID to select, and then click Select MatID.
Select MatID is available only at the Face sub-object level.
Select SG—Enables face selection by smoothing group. Specify the smoothing group to select, and then click Select SG.
Edit—Displays the Edit UVWs dialog.
Reset UVWs—Resets the UVW coordinates in the Edit UVWs dialog.
Clicking this is almost the same as removing and reapplying the modifier, except that a map assigned in the Edit UVWs dialog is not deleted. For example, if you forgot to turn on the Generate Mapping Coordinates check box for an object, and then applied the Unwrap UVW modifier, the modifier would have no UVW coordinates to use and its settings would be wrong. If you then go back in the Stack and turn on Generate Mapping Coordinates, you'd need to click the Reset UVWs button. When you click this button, an alert warns you that you're losing any edits you've made.
This option lets you choose a specific map channel by number, or the vertex color channel. For more information, see UVW Map modifier > Channel group.
When you change channels, you should reset your edits, since the edits for one channel usually won't work for the next channel. An alert appears that lets you choose between resetting the coordinates or leaving them as they are. In almost all cases, it's best to reset them.
This setting determines whether and how pelt seams and mapping cluster boundaries, also known as map seams, appear in the viewports:
Show Map Seam—When on, mapping cluster boundaries appear in the viewports as green lines.
The display thickness setting applies to both pelt seams and map seams:
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Thin Seam Display—Displays map seams and pelt seams on object surfaces in the viewports with relatively thin lines. The line thickness remains constant as you zoom the view in and out. Uses the Display seams color.
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Thick Seam Display—Displays map seams and pelt seams on object surfaces in the viewports with relatively thick lines. The line thickness increases when you zoom the view in and decreases when you zoom out. Uses the Display seams color. This is the default choice.
Prevent Reflattening—This option is used mainly for texture baking. When turned on, the version of the Unwrap UVW modifier automatically applied by Render To Texture, named, by default, Automatic Flatten UVs, will not reflatten the faces. Also, make sure that both Render To Texture and the modifier are using the same map channel.
You can apply planar mapping to selected faces, patches, or surfaces, and align the mapping gizmo in any of a variety of ways.
The mapping controls are available only at the Face sub-object level.
Note: When the Planar mapping button is active, you cannot change the selection without first exiting the mapping operation.
Planar—Applies planar mapping to the selected faces.
Make the selection, click Planar, adjust the mapping using the transform tools and Align buttons on the Map Parameters panel, and then click Planar again to exit.
Align X/Y/Z—Aligns the gizmo to the X, Y, or Z axis of the object's local coordinate system.
Best Align—Adjusts the mapping gizmo's position, orientation, and scale to fit that of the face selection, based on the selection's extents and average normals.
Fit—Scales the gizmo to the extents of the selection and centers it on the selection. Does not change the orientation.
Align To View—Reorients the mapping gizmo to face the active viewport and adjusts its size and position as necessary to fit the extents of the selection.
Center—Moves the mapping gizmo so that its pivot coincides with the center of the selection.
Reset—Scales the gizmo to fit the selection and aligns it with the object's local space.