Select an object. > Modify panel > Modify List > UV Coordinate Modifiers > Unwrap UVW > Edit button (on Parameters rollout) > Edit UVWs dialog toolbar > Unwrap Options
Set preferences for the UVW Unwrap Edit dialog using controls in the Unwrap Options dialog.
Interface
Colors group
Contains color swatches to customize the display of the UVW lattice. With certain maps, the default colors may become difficult to see. Use these swatches to choose colors that work better for your specific map.
Line Color: Specifies the color of the UVW lattice lines. Default=white.
Selection Color: Specifies the color of the UVW vertices. Default=red.
Preferences group
Contains controls affecting the map display in the view window.
Render Width: Specifies the width resolution of the image displayed in the view window. This does not change the size of the image, but only the resolution.
Render Height: Specifies the height resolution.
Use bitmap resolution: Turn on to use the bitmap's resolution. The image aspect ratio displays correctly.
Weld Threshold: Sets the weld threshold. The value is in UV space distance; it is normalized between 0.0f and 1.0f.
Constant Update in Viewports: Affects the adjusting of UVW vertices in the viewport while you move the mouse. Default=off (the effect of adjusting the UVW vertices does not appear in the viewport until you release the mouse).
Show Selected Vertices in Viewport: Displays selected texture vertices and the corresponding vertices in the viewport.
Mid Pixel Snap: Snaps to the center of pixels of the background images instead of pixel edges.
OK/Cancel/Defaults: Click OK to accept, or Cancel to cancel the changes in the dialog. Click Defaults to restore all of the settings in this dialog to their default values.