1 Preview: Shows the object that you are going to unwrap. The wireframe shows the geometry’s mesh. The faces of the mesh also act as the base for seams and directions when you are setting up the charts for unwrapping.
2. Quick Unwrap:
2.1 Unwrap Shell: This method can unwrap shells in one click. It is targeted at simple shells, which can contain holes - but will not be able to unwrap sphere geometry (ie. closed objects). For those you will have to use the Advanced Unwrap, where you can specify multiple charts and control where to add seams.
3. Advanced Unwrap: The Advanced Unwrap enables you to create multiple charts, select where you want seams, and also control the U-direction of the UV-coordinates.
3.1 Seams If the geometry is a sphere (closed geometry) or in some instances a cylinder (a surface with holes) UV unwrapping will require you to set one or more seams. This is where Add Seam comes into play.
Add Seam: This enables you to, in the preview, select where you want to have a seam. The seam will be highlighted in red. Enable Use as Direction Guide if you want the U direction of the UV-coordinates to follow the seam. When this is enabled, this type of seam will be highlighted in orange.
Use the buttons to cancel or apply the seam.
A chart includes a separate set of UV coordinates for a section of the surface. There are 3 methods for creating charts. The blue color shows what method is active
By Existing Charts: This method lets you re-select charts from the existing set of UV coordinates. If the object does not come with UV coordinates, this option will be disabled.
Flood Fill: This method will grow the chart until it meets another chart or a seam.
By Angle: The extent of charts added with this method depends on the angle between triangles in the mesh. The chart will stop when the angle between 2 adjacent triangles is larger than the angle set by the Angle slider.
Extend Chart: Enable this if you want to add to a chart. When enabled you have to click in a triangle that shares a face with the chart you want to add to - then the next chart will be added to that chart. How much is added depends on the active pick mode.
Add Direction Guide : This enables you to set the U direction for the UV coordinates. Note that the guides should not cross each other. The direction will be highlighted in green. You can add a direction guide both before and after adding the charts.
Use the buttons to cancel or apply the direction.
3.4 Unwrap When you are happy with your charts' seams and directions you can UV unwrap the object.
4. Position Charts Once you have unwrapped the object, the charts will be shown with a texture displaying how the UV’s flow.
Base UV Size: This slider lets you adjust the scale of all the charts.
Scale: If the charts do not match in size you can click a chart in the preview and adjust the scale of that.
Rotate: If you want to change the alignment of a chart you can select it in the preview and adjust this slider to rotate the UV’s of it.
Note that when you scale/rotate one chart, you may experience shifting of the UV coordinates on other charts - This occurs as a precaution to ensure that charts do not overlap in UV space.
Use Material Texture on UV Charts. Enabling this will let you see the current material texture of the part in the preview, before applying the new UV’s to the part. This is only available if there is a texture assigned to the material.
5. Clear At any point in the process you can press Clear. This will reset to the state of the object when the tool was launched.
6. Cancel/Apply: Cancel will close the tool without applying new UV’s. Apply will close the tool while applying new UV’s (if you have unwrapped). This cannot be undone.