Importing Data from Auxiliary Files

Importing data from auxiliary files enables you to develop a library of files and transformations that register objects to specific physical parts. Auxiliary files contain mechanical information about parts that you might want to view in relation to the PCB design. For example, you might want to add connecting cables, flexible circuits, other PCBs, or enclosures to see how the board and part assemblies fit together.

Auxiliary files come from a number of different sources. Table 3-1 lists the types of files that you can import into 3D PCB Viewer.

Table 3-1. Supported Auxiliary File Types

File Type	Extension	Description
Printed circuit board layout file	.pcb	This is the PCB design file created by Mentor Graphics Xpedition xPCB Layout and BoardStation XE PCB. In addition the design file that was initially loaded for viewing, .pcb files can be imported as auxiliary files.
Virtual Reality Modeling Language (VRML) file	.wrl	VRML is a standard file format for representing 3-dimensional interactive vector graphics.
object file	.obj	Object files are mechanical models created by tools such as Autodesk’s Alias Wavefront Computer Aided Design (CAD) software.
stereo lithography CAD file	.stl	STL is a file format (native to the stereo lithography CAD software created by 3D Systems) that is supported by many CAD software packages. STL files describe the surface geometry of 3-dimensional objects.

Auxiliary PCB imports display only components, padstacks, the pcb board, contours, mounting holes, and cavities. All Auxiliary imports can be individually scaled, rotated, etc.

Each auxiliary file import can be toggled on/off from the assembly tab of the display control. Individual pieces of a auxiliary file import, the components, contours, etc...., can not be toggled. The colors of an auxiliary file import follow the colors set in Xpedition xPCB Layout or BoardStation XE's display control in symbolic mode, or the render real colors in render real mode.

Importing an Auxiliary File

When you import an auxiliary file, you also need to translate (or align it) to the primary design in order to achieve a useful design view. To import an auxiliary data file and translate it, do the following:

In the 3D PCB Viewer window, select File> Auxiliary File Import from the menubar. This opens the Auxiliary File Import dialog box, shown in Figure 3-1 and described in Table 3-2.

Figure 3-1. Auxiliary File Import Dialog Box

Table 3-2. Auxiliary File Import Controls

Area	Option	Description
Aux File Instance	<filename>	The Auxiliary File Instance field allows you to either select an existing name from the drop-down list or to select <new> to create a new instance name.
Aux File		The Auxiliary File field specifies the full path to the auxiliary file to be imported. You can either enter the file name, or you can click the icon to use the browser to select the file path.
Scale		The fields in the Scale area allow you to change the relative size of the auxiliary file so that its size matches up with that of the primary design.
	Units Conversion	Use the Units Conversion field to select the units of measure that you want to convert between. For example, one of the selections is “in to mm”, which converts inches to millimeters. Selections made in this field are reflected in the Scale Factor and Size Ratio fields.
	Scale Factor	Use the Scale Factor field to enter a numeric value by which to scale the auxiliary data. Applying a Scale Factor changes the selection in the Units Conversation to custom.
	Size Ratio	The Size Ratio field displays the current ratio between the auxiliary file and the primary design. To change this ratio, you can either type a number into the Scale Factor field or you can select a scaling factor from the Units Conversion drop-down list.
Rotate		The icons and fields in the Rotate area allow you to rotate the auxiliary file around the x-, y-, and z-axis so as to correctly orient the imported object to the primary design. To rotate by 90°, click one of the two icons located alongside the appropriate axis. To rotate by any other degree, enter the numeric value in the adjacent field.
Offset		The icons and fields in the Offset area allow you to align the auxiliary file to the primary design. To move the auxiliary file a specified distance along a particular axis, enter the distance in the adjacent field. If you want to constrain the movement of the auxiliary file so that it cannot move in a particular direction, then click the lock icon alongside the appropriate axis. The three Align icons enable you to pick a point on the auxiliary file and a point on the primary design, and then automatically align the two points.
Redo and Undo		Undo: Cancels the last action you have performed. Redo: Performs the last canceled action again.

Click the (Browse) icon to open the Select Import File dialog box, select the auxiliary file, then click Open. The Aux File field shows the full path to the auxiliary file.

In the Aux File Instance field, select an instance from the drop-down list, or select <new> to create a new auxiliary file instance.

When <new> is selected, a new instance of the auxiliary file is created. Each separate instance is given the same name as the original file with an instance count appended to it. For example, if you import a file named My_Cell.wrl, the first instance is My_Cell 1, the second instance is My_Cell 2, and so on. While multiple instances of the same auxiliary file can be placed, only one copy of the file is stored and loaded.

The object being imported from the selected auxiliary file is displayed with a yellow, wireframe, bounding box.

Note
	If the Aux File Instance is <new>, a keyed in file name will only load if enter or tab is used within the Aux File entry field. If an existing aux import is already loaded, and it's filename is altered it will attempt to load on any loss of focus in the Aux File entry field. In both cases an invalid filename will color the field red and delete the current aux file import if any.

Caution
	Auxiliary PCB files are referenced from their selected positions and so are only linked into the design. Other types of auxiliary files are copied into the design and so are embedded within it. Therefore, when a design is moved, all the non-pcb data remains connected but the links might need to be re-established.

Figure 3-2. Auxiliary File Display

The 3D PCB Viewer displays the coordinate axes of both the primary (xPCB) design and the auxiliary (MCAD) design. The xPCB design axes are an RGB triad where positive X is red, positive Y is green, and positive Z is blue. The MCAD design axes are a CYM triad where positive X is cyan, positive Y is yellow, and positive Z is magenta. If the auxiliary file’s origin does not coincide with that of the primary design, then the 3D PCB Viewer displays both sets of axes. When the axes are coincident, they are dithered so as to display both sets of dashes.

Figure 3-3. Auxiliary File Axes When Offset and Rotated


	Tip: If desired, you can use the Display Control window to render the auxiliary file as a solid object. The auxiliary file is listed on the Assembly tab.

Set the scale so that the size of the imported data is correct relative to the size of the primary PCB.

VRML files and PCB designs can have defined units that are read and applied when the files are opened. If these units are undefined or are defined incorrectly, you must change the scale.

The Size Ratio field gives the ratio between the primary PCB and the auxiliary file. To change the ratio, you can either enter a custom scaling factor in the Scale Factor field, or you can select a standard factor from the Units Conversion drop-down list.


	Tip: Use the View> Fit All command in the 3D PCB Viewer to make sure that the whole design is displayed. The other Fit commands are based on the primary PCB design and therefore might not display the entire content of the auxiliary file.

Now that the imported object is the correct size relative to the PCB design, it needs to be rotated so as to be correctly aligned with the primary PCB.

There are three axes around which you can rotate the auxiliary design. The x- and y-axis are in the same plane as the PCB design. The z-axis is in the direction of the layer stackup.

Clicking the Rotate icons rotates the auxiliary design by ± 90 ⋯ about the associated axis. You can also enter the number of degrees of rotation, but non-orthogonal rotations are rarely needed.

The final step in placing an auxiliary file is to translate it so that it is correctly aligned with the primary design. The primary PCB design is anchored at its board origin, and all the auxiliary files are placed relative to it.


	Tip: It is possible for an auxiliary file to be placed relative to another auxiliary file. The best process for handling this scenario is to place the files that connect to the primary PCB design first, and work outward from there.

The 3D PCB Viewer includes an alignment tool that allows you to pick a from point on the imported object and a to point on the primary design, and then automatically align the two points.

Click the Look at Top button in the Toolbar.

In the Auxiliary File Import dialog box, click the (From) icon, then click the from point on the auxiliary file. The point is marked with a yellow X, as shown in Figure 3-4.

Click the (To) icon, then click the to point on the primary design. The point is marked by a yellow X and arrow extending between the picked points.

Click the (Align) icon to translate the auxiliary file so that the from point is on the to point.


	Tip: If the auxiliary file is rotated and positioned correctly, you can lock one or two of the axes to constrain the movement. This allows you to be less precise in your point selections.

Figure 3-4. Aligning the Auxiliary File with the Primary Design

When you are finished, click either Apply or OK to make the change permanent.

Caution
	You must click either Apply or OK to save an auxiliary file instance edit. When you select another instance without doing so, the edits on that current instance are discarded.

Whenever an auxiliary file instance is selected, its position can be edited. So, if you want to re-translate the auxiliary file, select it in the Aux File Instance field and make whatever changes are needed.