Importing the Source Models

Placing a 3D Model in the Workspace

A 3D model can be placed into a PCB document at any time. Note that the 3D STEP format model is not placed directly into the PCB workspace, it is actually placed in an Altium Designer 3D Body object. This approach, of containing the STEP model within a 3D Body object means that Altium Designer can manage and display STEP models and generic 3D body objects in the same way.

When the blank PCB is ready to import a model, first ensure that you are working on a mechanical layer, as 3D models can only be placed on a Mechanical layer. Then choose Place from the PCB document menu bar and select 3D body from the list. The 3D Body dialog will open and present you with the choice of model types. Select Generic Step Model and then click the Embed STEP Model button or Link to STEP Model button. Embedded STEP models are browsed directly for, while linked STEP models must be available in a pre-defined folder. Folders for linked STEP models are defined in the PCB Editor - Models page of the Preferences dialog.

When you have selected the model to embed or link, the data is read in and you are returned to the 3D Body dialog, click OK to continue.

3D Body Property Dialog showing the Embed and Link Options.

When the model is ready to be placed, a bounding rectangle will appear on the mechanical layer of choice. Clicking the select button on the mouse will place the model in the workspace and you will be presented with the 3D Body dialog again, ready to place susbsequent models if required. If this is the only model then click Cancel or press Esc to close the dialog, you will be left with the placed model highlighted as a hatched bounding shape.

3D Body Object on a Mechanical Layer.

To display the model in 3D, select View » 3D Layout Mode to switch to 3D.

2 views of the 3D Step Model.

The first thing to do is to check the representation of the model heirarchy in the PCB editor panel. By selecting 3D Models at the top of the panel you should then be able to choose Free models in order to display any modelling placed in the document which is not associated with a footprint. From this panel, you are able to select the transparency levels or indeed, hide a model as required.

You should be able to see any individual volume (part) nested in a two tier state in your source models. By hiding the cases and any other volumes, you will be able to see the horizontal alignment (standoff height) of the model blank against the board shape. According to how the model was formed in the first place with regard to a zero plane, the two will not usually be in agreement as to height.

PCB Menu to Define Board Shape from 3D Body

From the menu, now select Design » Board Shape » Define from 3D Body as shown in the image above. Use the small crosshair to click on the image of the source model assembly. You will then be prompted in the information messages at the top-left of the viewing pane to choose the face you wish to use to establish the correct board shape.

Choosing a Planar Surface on the 3D Model

During this sequence, the models will become translucent in order to allow you the opportunity to locate and select from blank PCB surfaces that are hidden inside an assembly.

Once you have chosen a planar surface, you will be prompted whether or not you wish to choose to hide the model that was used in order to inspect your board shape and to exclude the board model from subsequent Design Rule Checks. Included in this default dialogue prompt is the option to have the board Top Layer aligned with the surface you have chosen. This action will line up the model at the board top layer plane thereby ensuring the height of the entire assembly is correctly set with respect to the top of your board.

Board Outline Creation Options.

Should you need to manually place or set a board height with respect to your board model, you can select from the menu Tools » 3D Body Placement » Set Body Height option. In this feature, you are able to select the PCB blank model and determine the alignment point based on your selections from the model. First you select the model of choice, then a selection 3D cursor cross-hair appears. Use this to select a point on the surface in question. You are then presented with the choice of placement for the surface you chose from the model. You can place the model surface at a particular height above the top surface of the board, or you can in fact choose the surface of the board as the alignment plane and 'sit' the surface in question directly on the board surface.

The image on the left shows the unaligned 3D Model with Board Surface, on the right is the aligned 3D Model with Board surface.

Once you are satisfied, the board is now ready for placement of components.

At some point prior to exporting a populated board for use in a third party CAD tool, it will be necessary to set the stack heights in order to obtain a board thickness which matches that of the original model. Pressing the shortcut key Q in the 3D viewstate, this will alter the measurement units. When in 3D mode, pressing the key sequence D,K will bring up the Layer stack properties. The overall board thickness is shown at the top of the stack.

Board Stack Up in Layer Stack Manager

This is important if you wish to interrogate the board design volume in any third party tools. When replacing into an altium document, an export step file can be imported to assemble more complex mother/daughter board arrangements and the board in the step model will be the correct thickness. Again, the importance is placed on having correct overall heights when stacking boards together.

After populating the board, it will be possible to 'show' the surrounding model assembly of associated hardware and cases to check for clearance violations and practicality of assembly. In many instances, a reduced model containing no blank PCB board models may be required to avoid clearance violations with real board components.

3D View of Imported and Placed Components, Enclosure and Blank Board.

Linking and Revisions

One of the bonuses of source model linking is the ability to revise the original step model and automatically update the current PCB document using these models.

When originally importing (Placing) models into the PCB document, the 3D body properties for placing a new model includes the Link button option as opposed to Embed.

Link Option Through 3D Body Property Dialog

When this option is chosen, the directories for model repositories and the like are displayed. By default, a models directory is already created by Altium Designer and any models saved to this directory will be shown.

If your model path is elsewhere, you simply need to add the directory drive path to the lists. Click the Add Directories button. The Preferences screen for Models will open and display current paths in the list.

Click the browse folder icon at the end of the current address bar at the bottom of the display pane and navigate to the folder you wish to add to the directory listings.

Selecting External Model Folder

When you click the OK button, you will be returned to the preference list and your selected path will now display in the address bar. By clicking the ADD button, this address will now list in the viewing pane. Click the OK button at the bottom of the preferences window.

Adding Model Path to PCB Editor - Models Preferences

The 'Choose Model' window will now populate the panel with the models contained in the drive path. Any model may now be selected for placement.

Models Found in Linked Model Path

After selecting the model of your choice, Click the OK button. You should now see the filename of the model and the associated drive path in the 3D body properties dialog, ready to be placed.

Revisions

Should the source model go through a number of alterations and revisions, the Pcb document containing this model through a Linked placement can be updated in the following manner.

Image on the left below shows a board outline which has been altered with a small but critical notch.

Imported Model With and Without Notch

The board was exported as a step file (image on the right above) and included in an assembly of boards, the assembly PCB document will need to be updated to reflect the change. This model could be a step file of an entire board, fully populated, or as simple as a single component body step model. But in each case, any change in an original document needs to be updated to the final assembly. The importance in this example is that the original step file will be overwritten. By overwriting the original step file, the Pcb document is aware that a change has been made to an object linked to the document.

As soon as this change takes place, the open Pcb document will alert the user that a currently linked object has changed and will prompt the user as to whether or not they wish to update the current model to the new one on the model's drive path.

Warning of Change detected in Linked 3D Model

When accepted, the original model in the assembly will be revised as shown below, including all orientation data such that the new model will replace the earlier version using information contained in the properties of the previously placed model.

Revised Model After Accepting Changes

Exchanges

In the following example, all I wish to do is change from a neutral to a coloured model. The case of the example Developer Tool DT01 is currently an AP203, neutral type. I will be exchanging it for an AP214 coloured type.

Original Neutrally Colored AP203 Model

Exchanging can be done through the embed or the Link buttons and navigating to the desired replacement. After selecting the model of your choice, Click the OK button. You should now see the filename of the model (and the associated drive pathin Link) in the 3D body properties box, ready to be placed. Exchange step files do not need to be named equally.

Updated AP214 Now Including Colour