Back in our school days, we were asked to use blue ink while the teachers used red ink for correction. I also remember using multicolor pens to emphasize important points in my assignments and project works. Or, take maps where distinct colors are used to represent certain features, such as water bodies, vegetation, urban areas, and so on. Colors affect our perception and comprehension. You will agree if I say that the right use of color gets attention, enhances clarity, differentiates items, facilitates identification of issues, and hence improves productivity. In PCB design, colors are particularly important for the reasons just mentioned, and colors very aptly have been given significant preference in Allegro 3D Canvas.

A predefined set of color schemes are provided with Allegro^® 3D Canvas that assign unique colors to design layers and objects, and facilitate viewing and reviewing layout designs. You might choose any one of eight color themes or create a new one. That’s not all. Whether you are working in the bright and vibrant environment of your office or finishing an urgent inspection under the lamp at your home workstation in the night, you can customize the colors to suit your surroundings. In this post, I will walk through setting up color themes in 3D Canvas that will help you make your designs more informative and appealing.

But before that, I want to tell you about the 3D Canvas filter. When launching 3D Canvas either by using the 3D command or from the View menu in Allegro Layout Editors, the first prompt you see is 3D Canvas Filter. Here you choose what to load and bring into the 3D Canvas environment. You might choose to bring All Layers or Outer Layers and specific objects. The loading time will depend on the size of your database file.

Color Themes

Once your design is up, you can access 3D Canvas settings via the Setup menu. In Allegro 3D Canvas Preferences, there are different categories. Here we will focus on Color Themes under Appearance. You can change the color of the 3D canvas background, rigid-flex etch and mask layers, and can also adjust the opacity for each layer. While reviewing designs you can play with multiple color options and save the modified color themes. To make it easier, copy and delete options are there to create and remove all your redundant themes.

Default Color Theme

Any design when first opened in 3D Canvas shows the design colors by default, and, hence Color Theme is set to Design Colors. This means that the color for each Etch or Plane layer assigned in Allegro Layout Editor will be used to represent the color for all the objects on the corresponding conductor or plane layer in 3D Canvas. Similarly, for mask layers the corresponding colors are picked from design in a 2D editor and are used to represent all objects using the same color on the respective layers.

When design colors are used, the background color in 3D Canvas is always set to white and the default opacity levels are set to 100% for each layer other than soldermask for which it is set to 65%.

Predefined Color Themes

To mimic the look of a real-world PCBs, a set of predefined color themes are also available. These color themes are named based on the color of soldermask you would prefer to see. For instance, with the Dark_green theme, the color of soldermask changes to dark green. Note that the outer etch, inner etch, plating, and dielectric colors remain consistent through these themes. To provide a real-world PCB look, the color copper is assigned to outer etch, inner etch, and the plating. While wires are shown in gold color.

Custom Themes

In the predefined color themes, you can only change the 3D Canvas background color. To give you more control over your requirements, an option to add a custom theme has been provided through right-click mouse options. Select any existing color theme and right-click to add a new theme. Specify a name to the theme and you are ready to create a new custom theme. As soon as you do this, the new color theme is automatically selected in the color theme list and all the layers set to black color with maximum opacity. You can now choose color of your choice from the color palette and assign it to each layer type under that theme. You can keep changing the colors until you find the right one. Once you click the Apply button, the color assignment is saved and loaded when 3D Canvas is reopened. The Delete and Copy options are enabled only for your custom themes.

The custom color theme immediately affects the layer colors in the Visibility tab of 3D Canvas as you can see in the following image.

All the 3D Canvas preferences including the color theme settings are saved in an XML file format in your pcbenv directory. An example of how this file looks like is as follows:

<CustomThemes>

<Custom_1>

<outer red="170" alpha="255" blue="0" green="85"/>

<inner red="170" alpha="255" blue="0" green="85"/>

<dielectric red="247" alpha="255" blue="175" green="255"/>

<plating red="255" alpha="255" blue="0" green="170"/>

<soldermask red="85" alpha="255" blue="0" green="170"/>

<silkscreen red="255" alpha="255" blue="0" green="0"/>

<coverlay red="170" alpha="255" blue="0" green="0"/>

<background red="0" alpha="255" blue="0" green="0"/>

<symbols red="85" alpha="255" blue="255" green="0"/>

<wires red="255" alpha="255" blue="0" green="170"/>

</Custom_1>

</CustomThemes>

<ActiveTheme ActiveTheme="Custom_1"/>

Conclusion

As I said in the beginning, colors are a powerful tool that grabs attention and creates positive user experiences. With 3D Canvas capabilities, there are lots of possibilities to customize the design of how you want to check and view in 3D. In my future posts, I will discuss other aspects of visualization controls in 3D Canvas. Till then keep exploring!