Since the same model can be attached many times, the logical name helps you distinguish between references.

• Coincident — Aligns the references with regard to design plane coordinates only.
• Coincident World — Aligns the references with the active model with regard to both Global Origin and design plane coordinates.
• Geographic – AEC Transform — Calculates the linear transform that gives the best approximation to the results of performing the full reprojection algorithm, if the active model and the reference have geographic coordinate systems. The approximation is acceptable for smaller scale data, such as most man-made structures occupying less than a square kilometer.

  When the geographic coordinate system is created from placemark monument points, it maintains angles and consistently scales the model relative to the primary placemark monument point and the scale of the data at that point in the coordinate system.

  For geographic data, the results are unlikely to be acceptable. To evaluate if this method is an acceptable approximation, the maximum error is displayed in the Description field. It is calculated by applying the exact calculation to each corner of the reference range and comparing that position to the position calculated from the transform. For references covering geographically small areas, the errors are typically small fractions of a meter. The advantage of this georeferencing method is that it gives the same performance as other reference attachments, since reprojection is not necessary.

  When two models use the same base geographic coordinate system with the only difference being their local transforms, Bentley View can calculate an exact linear transform between the two models.

• Geographic – Reprojected — Reprojects all data in the reference model from the reference model’s geographic coordinate system to the active model’s geographic coordinate system, if the active model and the reference have geographic coordinate systems. The reprojected data is stored only in memory (since the reference is not changed), so the reprojection calculations happen each time the reference is loaded. This increases the time required to open the active model but is more accurate.

  This orientation mathematically recalculates points in the reference model to align with corresponding latitude/longitude points in the active model.

• Standard Views — Identifies the views that can be used to display the reference: Top, Front, Right, Isometric, Bottom, Back, Left, or Right Isometric. If the file being attached is 2D, you can choose only the Top view.
• Saved Views — Identifies the saved views that are available in the reference.
• Named Boundaries — Identifies the named boundaries that are available in the reference. When a 3D model is selected for attachment, you can expand a named boundary and select a standard rotation to apply to the view attachment. For example, if you select a named boundary, then expand it to select the Top view, the extents of the named boundary are used, and the orientation is the top view.

  When a named fence is used to attach a reference, all levels are on. If a particular level is desired, then use the named fence as a clip volume for a saved view in the reference, and select the saved view.

When attaching a reference (a design or drawing model) into a sheet model, the referenced model's annotation scale is applied as the default detail scale, and the reference scale (Master:Ref Scale) is calculated from the detail scale and the sheet annotation scale. However, if the reference model’s annotation scale is Full Scale 1:1, the default detail scale is set to be same as the sheet annotation scale and the reference is attached at full size.

The scale of line styles within a reference can be affected by the global line style scale of either the active model, the referenced model, both, or neither.

• None — Neither the active model's nor the reference model's global line style scale is used to scale the cosmetic custom line styles.
• Master — The active model's global line style scale is used to scale the cosmetic custom line styles.
• Reference — The referenced model's global line style scale is used to scale the cosmetic custom line styles.
• Master * Reference — The active global line style scale is multiplied by the referenced models' global line style scale to scale the cosmetic custom line styles.

In order to change the appearance of a reference, you have to modify the saved view that it is synchronized with. This is to ensure fidelity of display properties such as view attributes, view display, clip volume, display styles and others.

When synchronized, the reference location is also realigned. Specifically, when the reference is synchronized with the saved view, the reference center and saved view center remain aligned. You can see the effect of this in two ways:

1. In an unsynchronized state, that is when this drop-down is set to Volume Only, Presentation Only, or None, the reference is first shifted and then synchronized.
2. When synchronized, that is when this drop-down is set to All Settings, the saved view center is changed; for example, the saved view is stretched.

In case of Volume Only, the clip volume and camera position is taken from the saved view. So if you change the original saved view, its clip volume as well as camera position will be changed. Also, the clipping is computed from the saved view boundary. Hence you cannot clip or mask the reference in Volume Only.

The Presentation Only option is similar to Volume Only, except that in Presentation Only, you can modify the reference clip boundary.

The icons correspond to columns in the References list box and information panel.

If an icon is pressed, the setting is on. Click the icons to toggle the settings on or off.