Overlay pages

The overlay process in Revu lets you compare two or more PDFs by converting each document to a different color and stacking them on top of each other as layers in a new PDF. Each layer is transparent and blends with the layers below it. Where the colors are stacked directly over each other, they blend to create a darker color, making it easier to see which elements have changed and which ones have remained the same from revision to revision. There is also a batch version of Overlay.

This feature is similar to Compare Documents, which compares two or more PDFs and uses markups to identify differences. The Overlay function works well for PDFs with vector graphics, while Compare Documents is best suited for working with scanned images or drawings.

To overlay pages, see Align PDFs with Overlay Pages in Revu 21.

Revu 21 users must have a Core or Complete subscription plan to use the Overlay Pages feature. For more information about features and functionality available for each Bluebeam Plan, click here.

In the example below, an overlay was created from two revisions of a drawing, with the first revision converted to red and the second to green. When the same line existed in both drawings, they stacked to create a dark, nearly black line, indicating areas where no changes had been made from the one revision to the next.

Where something was in the second revision that was not in the first, a green line appeared.

Where something was present in the first revision and was not in the second, a red line appeared.

This made it easy not only to see changes made from one drawing to the next, but to know what had been added and what had been removed.

The default overlay settings in Revu are changeable. To access the default settings, go to Batch > Overlay Pages and select Edit Defaults. Change any of the available settings, as desired, and select OK.

  • Appearance: Sets the default line color of the Layers. To change the default line color for a Layer, select the color box and select the desired color.
  • Default Background: Set the default background color. The default is transparent. To change the default background colorselect select the color box and select the desired color.
  • Default Blend: Determines how the color of overlapping elements are treated.
  • Default Opacity: Sets the transparency of the content in the Layer. Range is from 0% (fully transparent) to 100% (fully opaque).
  • Auto Align Limit: Filters out objects smaller than the selected limit. Larger values (such as 1/8 inch) may improve performance but don't align smaller details, while smaller values (such as 1/32 inch) may include more detail but could impact performance.
  • Advanced Color Shading: When enabled, the overlay process will employ advanced shading methods when blending colors, allowing for greater detail in the resulting drawing.
  • Include Flattened Markups: When enabled, overrides the default behavior that ignores markups that have been flattened as "recoverable".
  • Position:
    • Rotation: Sets the default rotation (in degrees) of the Layer. Range is from 0 to 360.
    • Scale: Sets the default scale of the Layer, where 1.00 is equal to 100% (so, for example, a 75% scale should be entered as .75 while a 125% scale should be entered as 1.25). Select Scale Adjustment to enable.
    • Offset X & Y: Sets the default offset position of Layer along the X and/or Y axes.

Related topics

Batch Overlay