# FixtureFromPointsToPoints3D

The FixtureFromPointsToPoints3D function constructs a fixture that maps 3D points and shapes from space B to space A, using corresponding 3D points from the two spaces. The input points must be non-collinear.

The FixtureFromPointsToPoints3D function helps to generate a Fixture3D transform using N points from coordinate space A and the same points from coordinate space B. The number of points must be at least 3.

To convert points from 3D camera space to robot space, you have to set the coordinates of these N points in both the 3D camera space coordinate system and 3D robot space.

As an example, you can use the 4 top corners of the Frustum:

- To know the 3D coordinates of the 4 corners in robot space, use a tactile device.
- To know the 3D coordinates of the 4 corners in 3D camera space, use spreadsheet functions, like PointFromLines3D.

If you want the Fixture3D to convert points from camera space to robot space, set first the points in robot space, and then in camera space.

As an example, when you have a Fixture3D structure, you can use a Point3D function to get the picking point in robot space by using the picking point in 3D camera space and the previously computed Fixture3D.

Inputs

The FixtureFromPointsToPoints3D function has the following syntax:

FixtureFromPointsToPoints3D(Point3D A0, Point3D A1, Point3D A2, [Point3D A3, ..., Point3D AN], Point3D B0, Point3D B1, Point3D B2, [Point3D B3, ..., Point3D BN])

The first N points corresponds to the points in A space, and the other ones corresponding to the physical same points, but in space B.

Outputs

The FixtureFromPointsToPoints3D function returns a Fixture3D structure.

Vision Data Access functions

The Structures 3D Vision Data Access functions which create the result table are:

Function | Description
GetRotation(Fixture3D) | Returns the rotation of the Z-axis in degrees, also known as the in-plane rotation.
GetTilt(Fixture3D) | Returns the tilt angle of the Fixture3D structure in degrees on the Z-axis.
GetTiltDirection(Fixture3D) | Returns the tilt direction angle of the specified Fixture3D structure in degrees. The angle is measured in the X-Y plane of the original reference coordinate system, and specifies the direction for the projection of the tilted Z-axis onto that plane.
GetX(Fixture3D) | Returns the X-axis coordinate of the constructed fixture.
GetY(Fixture3D) | Returns the Y-axis coordinate of the constructed fixture.
GetZ(Fixture3D) | Returns the Z-axis coordinate of the constructed fixture.

The Structures 3D Vision Data Access functions are not automatically inserted into the spreadsheet. By default, Fixture3D appears without getters in the cell A21:

To display get functions, right click on the Fixture3D cell and select Insert Getters from the dropdown:

After you click on Insert Getters, the Structures 3D Vision Data Access functions appear in another Fixture3D structure in the cell A15: