Current Help System: PC-DMIS Laser (View Core Help)

#### Filter COPOPER

Pointcloud Operator dialog box - Filter Operator

This operation filters data to a smaller subset of points.

Applying the Filter operation to a Pointcloud can be done by clicking the Filter Pointcloud button from the Pointcloud toolbar or by selecting the Operation | Pointcloud | Filter menu item.

The Filter Operator uses the following options:

- Type – Indicates the type of Filter operator to apply: NONE, UNIFORM, RANDOM, CURVATURE or DISTANCE.

NONE – PC-DMIS does not filter the point data.

UNIFORM – Generates a subset of points distributed evenly in the X, Y, and Z directions. It will produce the same effect as a regular grid in 2D, but in this case the effect is a 3D grid.

RANDOM – Generates a subset of points randomly distributed in the pointcloud.

CURVATURE – Generates a subset of points with the highest estimated curvatures, mainly around edges, vertices, and highly curved areas of the surface.

DISTANCE – Generates a subset of points where points are at least the specified Distance value apart from each other.

- Distance – Specifies the distance for the distance filter.

To filter COP data:

1. Select a filter type from the Type list.

2. Select the Pointcloud command you want to apply the filter to form the list of commands

3. Specify the number of points or percentage of points to keep after applying the filter in the Reduced or % boxes. This does not apply to the Distance filter.

4. Click the Apply button.

PC-DMIS filters the data and the Graphics Display window shows the result. The size of the filtered data may differ slightly from the value that you specified. It is even more noticeable when the program is executed and the data is collected from scan commands. It is generally impossible to get the same number of points from a laser sensor that is repeatedly scanning the same entity.

5. When you are satisfied with the result, push the Create button. PC-DMIS adds a COPOPER/FILTER command to the part program containing all the information regarding the filter that you just applied.

Clicking Create inserts a COPOPER/FILTER command into the Edit Window like the following examples:

COPOPER3=COPOPER/FILTER,UNIFORM,SIZE=3000

REF,COP1,,

In the example above, if the initial size of COP1 was 10,000 points, the filter replaces the 10,000 points held in COP1 with the filtered 3,000 points, so that COP1 now holds the filtered 3,000 points for its cloud of points. PC-DMIS flags the 7000 points it didn’t use, so that you can undo the filter operation, using the COPOPER/RESET operation. Or if you desire, you can permanently purge the 7000 points not used using the COPOPER/PURGE operation. See “Reset COPOPER” and “Purge COPOPER” for more information.