BoardSurfers: How to Map CAD Models in 3D Canvas

In the world of PCB design, shorter delivery deadlines have less scope of re-spin cycles. Before manufacturing the board, every designer wants to see what the manufactured board would look like. Allegro 3D Canvas, enabled within Allegro^® PCB Editor, can help designers virtually view their designs in 3-dimensions by assigning 3D models to component footprints. This 3D viewer gives a better "What You See Is What You Get" (WYSIWYG) feel of the final product while designing the layout and much before manufacturing. Applying correct 3D models facilitates designers to measure the closest distance between placed components. They can also run collision detection checks with a specified spacing value to ensure the manufacturability of the board.

To map 3D CAD models, Allegro 3D Canvas provides a unique mapper interface that lets you assign models to the component symbol (.dra) as well as on a board (.brd). The 3D Mapper not only supports standard STEP (.step and .stp) models but other native MCAD model formats, such as Solidworks (.sldprt), NX(.prt), Parasolid (.x_t), AutoDesk Inventor (.ipt), ACIS (.sab, .sat), and Creo (.prt). It gives you an added advantage to choose between 3D models for mechanical components (covers, brackets, enclosures) and a wide range of interoperability between various CAD tools and Allegro PCB Editor.

In this post, we explore the capability to map CAD models to components in 3D Mapper. The methodology to map remains the same irrespective of the type of model you choose.

3D Mapper Interface

The mapping of CAD models can also be modified within the 3D Canvas window using a newer, interactive interface named 3D Mapper. This interface provides a better way to map components or devices to their respective CAD models. A set of orientation handles helps you map CAD models to footprints within the 3D Canvas environment. You can map both Primary and Secondary models according to your requirement. You can also modify model assignments and evaluate the design. It gives you a better perspective of your design.

An auto-mapping feature is also available that automatically matches the pins of the symbol to the CAD model. This option avoids the hassle of mapping pins manually to each model and improves user efficiency.

With 3D Mapper, you can map the 3D model to a footprint, device, or mechanical component. All the available footprints, devices, and mechanical components are listed in the MAP TO section and can be searched using the Search filter. When you select a footprint from this list, the tool centers it in the canvas and displays a 3D preview in the left of the 3D Canvas window.

Mapping Controls

To map a model, first, browse an appropriate model and load it into 3D Canvas. Using the AUTO button in the CONTROLS & MAPPING INFO section, you can map the model directly to the footprint without any manual intervention.

 

                                                   Auto-Mapping                                                                                                        Manual-Mapping

Additional controls such as TOP, BTM, XY, and Z are also available for specifying rotation and offset values for the X, Y, and Z coordinates. You can use the TOP or BTM buttons to select the face of the model and align it on either top or bottom of the footprint. When you do that, the model automatically snaps to the footprint. The XY and Z buttons are similar in function and help you move the model in the context of the footprint in either XY or Z directions, making it easier to map the model.

Custom Color Scheme for Models

To distinguish the assigned model from the rest of the others, you can change its color. A color swatch available next to the Model File option lets you choose a custom color for the imported model. By default, the model color is the same as the original model.

File-based Mapping 

Mapping models, one at a time, is troublesome. For faster and error-free mapping, use Import and Export options. A .map file can be used to map individual components all at once. This map file is an XML format that stores relevant mapping information. You can further modify it to suit the design requirements. Here is an example of the XML file:

Takeaways

With 3D Mapper, you can import any CAD models and view all the mechanical objects, such as shields, fans, heat sinks, and housings in Allegro 3D Canvas. You can visually check, run collision detection, and fix the placement issues before sending your board for manufacturing.

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