Mapping

## Mapping

Calculate the conversion relationship between two camera coordinate systems, this module is mainly used for dual-plane alignment.

![](/media/202601/2026-01-15_150903_7532580.16406475188028413.png)

## Module Principle
A calculation module that records the conversion of pixel points on two planes. The mapping used for alignment is linked by the machine to the two planes. The machine can move an object from one plane to another through a **fixed displacement**. This fixed position is the premise for generating mapping.

![](/media/202603/2026-03-12_153649_3171600.986145369224654.png)

Generating mapping requires checking the coordinate system tree connection of global variables, used to record mapping data.

The input points of the mapping module are multiple one-to-one corresponding point pairs selected on two planes respectively, to calculate the conversion relationship between the two planes. Minimum is two point pairs. The more point pairs, the more benchmarks used to calculate the mapping, and the more accurate the calculated mapping will be. When the number of point pairs is the minimum two pairs, it should be noted that on the same plane, these two points cannot be the same or very close in the value of x-axis or y-axis, which will increase the error and affect the mapping calculation.

![](/media/202603/2026-03-12_153501_5756800.5036935282256415.png)
Mapping that does not check Mechanical Transfer Mapping does not need to input mechanical and calibration information, that is, these two planes are not planes linked by machinery. It is just the conversion of points on two planes, which is a form of calibration.

![](/media/202603/2026-03-12_153432_8323150.7305914482611121.png)
For mapping used for alignment, that is, when two cameras shoot the same machine on the plane, Mechanical Transfer Mapping needs to be checked. Introduce calibration data to record the departure position and arrival position. When the fixed displacement of the machine moving in the two planes has angle rotation, it is necessary to manually input the departure position and arrival position at the mechanical pose. When the mechanical displacement does not rotate, there is no need to modify. The rotation in the fixed displacement and the plane angle of the two mapping planes are different. Only when the fixed displacement of the machine has an angle change, it will affect the calculation method of mapping.
#### Plane Angle:

The plane angle is the angle at which the two planes rotate. Even if the fixed displacement of the machine does not rotate, there will be a plane angle.

![](/media/202601/2026-01-15_151924_9908330.8989077430778271.png)

The coordinate system of the image is the origin at the top left, x-axis horizontally to the right, and y-axis horizontally downward. The plane angle photographed by the two cameras is related to the installation method of the camera.

## Usage Scenarios
Generally used during mechanical alignment, to link the conversion relationship between two planes. These two planes are usually the same machine photographed. Generating mapping requires the machine to carry the workpiece on these two planes to walk a fixed displacement. Ordinary two planes can also be mapped to convert the pixel positions in the images under the two cameras to each other.

![](/media/202601/2026-01-15_150737_9251900.0012835665890853498.png)

Departure position shooting:

![](/media/202601/2026-01-15_150758_2206770.839714777162138.png)
Arrival position shooting:

![](/media/202601/2026-01-15_150814_0932730.39170654311490505.png)
## Usage Method

### Pre/Post-Sequence Modules

Camera image acquisition, circle extraction (line extraction, etc.) to acquire image points. Input the departure and arrival points into the mapping, and the mapping can be generated.

![](/media/202603/2026-03-12_153701_4549780.11430631473269004.png)

Generally, after the departure machine takes a photo at the departure camera, it needs to move to the arrival camera to take a photo to acquire the arrival point. You can use two flows to complete the mapping. In the first flow, store the points obtained from the departure position shooting into the global variable, and in the second flow, take out the stored departure point data and generate the mapping.

## Parameter Configuration Description
【Mapping Times】 Select mapping times according to single-point multiple mapping, multi-point multiple mapping or multi-point one-time mapping in actual scenarios. 【Single Point Pair】 The number of point pairs per mapping.
【Calibration Group】 Select the corresponding coordinate system group, and the mapping data will be recorded in the mapping file under this coordinate system group. The coordinate system group must be set in the Coordinate System Calibration in Global Data Management.
【Mapping File】 Select the mapping file under the corresponding coordinate system group, and the mapping data will be recorded in this file. (The mapping file must be set in the Coordinate System Calibration in Global Data Management. First add a coordinate system group, then drag the two cameras to the window under the corresponding coordinate system group, select the connection line to connect the two icons, and the mapping file can be generated.)
Mechanical Pose:
【Mechanical Hand Departure Pose】 The physical coordinate of the mechanical hand in the departure plane during the mapping process. (Default is the calibration center pose)
【Mechanical Hand Arrival Pose】 The physical coordinate of the mechanical hand in the arrival plane during the mapping process.
【Mechanical Transfer Mapping】 Mapping that does not check Mechanical Transfer Mapping does not need to input mechanical and calibration information, that is, these two planes are not planes linked by machinery. It is just the conversion of points on two planes, which is a form of calibration.

## Output Description
The generated mapping data can be viewed by clicking Mapping Data, or viewed through the coordinate system tree of global variables.

![](/media/202603/2026-03-12_153727_8021050.3728420343237543.png)

The mapping plane angle in the figure is -109.119° but the rotation of the mechanical displacement is 0°.

## Precautions
1. When there are multiple feature points of the mapped object that can be extracted, multiple points can be mapped at once, that is, the number of mappings is 1, and the single point pair is multiple. Note the order of the multiple feature points. When connecting the departure point and the arrival point, the same feature point needs to correspond. Such as:

![](/media/202601/2026-01-15_151257_2022350.48375450574247614.png)

2. When the feature point of the mapped object is difficult to extract, one point can be extracted, and then the mapped object is moved and photographed multiple times to obtain multiple points for single-point multiple mapping, that is, the number of mappings is multiple, and the single point pair is 1. Such as:

![](/media/202601/2026-01-15_151336_4115230.1580939950937864.png)

3. The interval between mapping points is best greater than 2cm to reduce mapping errors.
4. The generated mapping plane needs to be the same height as the plane using the mapping, and the photographing position is the same.
The points on the two planes must correspond one-to-one when generating mapping.
5. When the number of point pairs generating mapping is two pairs, the two points on the same plane cannot be the same or very close in the value of x-axis or y-axis. This will increase the error and affect the mapping calculation.
6. When there is angle rotation in the mechanical fixed displacement, you need to manually modify the mechanical departure position and mechanical arrival position. When there is no angle rotation, you need to pay attention that the angle of the mechanical departure position and the mechanical arrival position needs to be the same. Otherwise it will affect the calculation result.
7. The points used to generate mapping generally use circle center extraction or line intersection. Optimized feature matching points cannot be used.
8. Mapping has a departure plane and an arrival plane, and attention should also be paid to the conversion method when using it. If converting points on the arrival plane to the departure plane, inverse operation needs to be selected.
9. The object making the mapping is best to be the same as the position used in actual use (alignment and other projects) to improve accuracy.

[【Attachment】Mapping Example Project.rar](/media/attachment/2026/03/%E6%98%A0%E5%B0%84%E7%A4%BA%E4%BE%8B%E5%B7%A5%E7%A8%8B.rar)

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Click here to jump to the corresponding Chinese manual page: [Mapping](/doc/136)