17.5 - Filters

A “filter selection” constraint makes a Feature remove unwanted Features. This is convenient when you have a large number of Features in your Configuration Model. With the “Filter Selection” constraint you can create a more clear path for the users. In this lesson we’ll go over some common mistakes. We will also go over a method to create a Coöperating Filter Selection for you Configuration Model.

Common Mistakes - Filters

The most common made mistakes when working with Filters are:

• Filters in combination with Optional Features.

• A Filter that Filters itself.

 Filters in combination with Optional Features.

The first Example we’ll go over are Filter that are canceling each other out. For this example we use the configurator for a LEGO brick.

As you can see, you can filter the bricks based on color. If you select the red color, all bricks except the red ones will be removed from the configurator. But, there is a problem with this configurator. If the blue color is checked, you will see that it will not show any Bricks.

Because the Child Features under the Color parent-Feature are optional, the user is able to pick multiple colors. This will cause a filter to cancel each other out. This can be fixed by changing the Optional Features to alternatives. In that case, it is only possible to select one color.

A Filter that Filters itself.

Let’s go over another Example. In this example we will look at a Filter that is filtering itself. In this configuration, every “Filter Selection” have been set from each color to the corresponding Features. But, every Feature is put under the same parent Feature. The "Filter selections" will take place within this Parent’s Children.

If we choose a color again, you will see that every Brick will be filtered out of the Configurator. 

The reason for this is that the chosen Feature tried to remove itself. The color Red removes all Features except Red LEGO bricks. Therefore "Red" should also be removed. So, our tip is, to always  try to set Filter selections to Children of a different Parent (non-siblings).

Coöperating Filters

When building your Configuration Model, you can also implement a Coöperating filter. With this function, you add two filters to a big list of items. Let's stay with the configurator for a Lego Brick. 

In this model, Filter selections" have been set from each shape to corresponding Features and from each color to corresponding Features. If we check a shape, you will see that all the shapes that don’t correspond to the chosen shape, will be filtered out. If you also choose a color you will see that only one brick remains.

If we look into the logic of this configuration model, you will see that the whole configuration of the brick is separated in 3 parent features with the corresponding Child Features underneath. The filter selection is applied to the Shape and Color Feature. With the shape Feature we Filter out every Brick that don’t correspond to that shape. 

If we open the filter constraint of the 1x1 Feature, you will see that every Brick except the 1x1 bricks will be filtered out of the Configurator. When we do the same for the colors, we create a Coöperating filter selection. Where the bricks will be filtered on Color and shape.