# Features Finder

AlignPlus uses various types of features finders to locate the various types of features. Point, line and generic features finders are used to locate point, line and generic features respectively. Each features finders receive images from the multiple cameras that capture the image of a part, locate the features using the finders that are added by the user, and output a list of found features. The user can use HMIs that are available in the application to add the finders required to locate the features. The HMIs are designed to ease the addition and setup of the finders.

## Feature Finder

A feature is a characteristic of a part. It can be a point feature such as corner or fiducial, a line feature or generic feature. A finder is a tool that is used to locate this feature. AlignPlus allows one to add multiple finders that locate the same point feature. By default, when a finder is added, it is associated with a unique feature with the same name as the finder. The user has the ability to reassign the feature associated with the finder. AlignPlus uses the location computed by the finder with the highest score during pose computation.

For all line and generic features, the user can associate one feature with one finder.

Here is a summary of all available Features Finders supported by AlignPlus:

Features Finder Type | Feature Finder Type | VisionPro Tools Beneath | Function
--- | --- | --- | ---
Point Features Finder | PatMax Pattern Finder | CogPMAlignTool | Find a pattern on part
Corner Finder | CogFindCornerTool | Find a corner point
Custom Tool Block Point Finder | CogToolBlock + other tools user choose | Customized VisionPro Toolblock to find a point
Line Features Finder | Line Finder | CogFindLineTool | Find line segment on part
Custom Tool Block Line Finder | CogToolBlock + other tools user choose | Customized VisionPro Toolblock to find a line segment
Generic Features Finder | Custom Tool Block Generic Finder | CogToolBlock + other tools user choose | Customized VisionPro Toolblock to find a generic feature that is defined by user

The output features are stored in the following three type of AlignPlus classes:

- CogAlpsPointFeature

  Stores x, y and theta of found point feature using a point features finder.

- CogAlpsLineFeature

  Stores line segment of found line feature using a line features finder.

- CogAlpsGenericFeature

  Stores user defined feature located using a generic features finder.