> For the complete documentation index, see [llms.txt](https://stage-precision.gitbook.io/grid/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://stage-precision.gitbook.io/grid/camera-calibration/using-the-calibration-object/setup-calibration-object.md). # Setup Calibration Object After the required project setup is prepared, create or select a **Calibration Object**.
The Calibration Object is where the selected calibration workflow is configured. It connects the camera image, Calibration Screens, Measurement Points, maps, profiles, output settings, and workflow-specific objects. {% hint style="info" %} The available settings depend on the selected calibration workflow. Some tools only show a subset of the options described on this page. {% endhint %} *** ## Load a Calibration Workflow Select the Calibration Object and open the **General** tab. Click **Load Calibration** to choose the calibration workflow you want to use.
After a calibration workflow is loaded, the Calibration Object shows the settings required for that workflow. #### Choose the Correct Workflow Select the workflow that matches your physical setup and calibration goal. Examples include: * **Lens & Tracking Calibration** * **Lens & Tracking Calibration (Rotation Only)** * **Lens Calibration** * **Tracking Alignment** * **Alignment with Markers** * **Axis-Pole Calibration** * **Simple Static Calibration** * **Simple Static Calibration with Marker** #### Workflow-Specific Settings Each workflow shows different parameters. For example: * Lens workflows may show Lens Profile outputs. * Tracking workflows may show map inputs and Alignment Profile outputs. * Screen-based workflows may show Calibration Screen lists. * Marker-based workflows may use Measurement Points. * Axis workflows may require an Axis 2D object. * Static workflows may require a Camera Object. {% hint style="info" %} If a setting is not visible, it is usually not required by the selected calibration workflow. {% endhint %} *** ## Select the Image Input Most calibration workflows require a live image from the real camera. This image is selected in the Calibration Object. #### Image Field Use the **Image** field to select the Media Input that provides the camera image.
A project can contain multiple Media Input objects, so make sure the selected Media Input belongs to the camera you want to calibrate. #### Raw Camera Image The selected image should be the raw camera signal. Do not use an image that is already: * undistorted * distorted * cropped * scaled * composited * processed by another system {% hint style="warning" %} Using a processed image can produce incorrect calibration results. Grid Studio needs the original camera image so it can calculate and apply the correct lens and alignment data. {% endhint %} *** ## Add Calibration References The Calibration Object needs calibration references that are visible in the camera image. Depending on the selected workflow, these references can be **Calibration Screens** or **Manual Markers / Measurement Points**. #### Calibration Screens For screen-based workflows, add all Calibration Screens that should be used during the calibration.
These can be Single Screen or Multi Screen Calibration Screens. Make sure the correct Calibration Images are displayed on the physical Reference Surfaces before capturing calibration data. #### Master Screen Some workflows require one Calibration Screen to be selected as the **Master Screen**. The Master Screen is used as the fixed reference surface. Grid Studio keeps the Master Screen static and moves or solves the other related objects around it. Use a Master Screen that is well measured, clearly visible, and represents a reliable reference in the setup. {% hint style="info" %} The Master Screen helps define where the calibrated system is anchored in 3D space. {% endhint %} #### Measurement Points Marker-based workflows use **Measurement Point** objects instead of Calibration Screens. These points are referenced manually in captured camera images using the Manual Marker Editor. Measurement Points must be created in the Project Tree before using a Manual Marker workflow. *** ## Select Maps Moving camera workflows require tracking, encoder, or movement data. This data is provided through maps that are usually created on the Camera Object, Axis 2D object, or another target object. The Calibration Object links to these maps in the **Maps** section. #### Map List The **Maps** section contains a **Map List**. Each entry in the Map List references one map and defines which parts of that map should be used by the calibration workflow.
#### Input Map Use the **Input Map** field to select the map that should be used by the map entry. A typical camera workflow uses a map from the Camera Object. ``` Tracking Object ↓ Map Input on Camera Object ↓ Calibration Object → Maps → Map List → Input Map ↓ Calibration Workflow ``` {% hint style="warning" %} Make sure the selected Input Map belongs to the correct camera setup. Selecting the wrong map can cause the calibration to use incorrect tracking or encoder data. {% endhint %} #### Map Entry Options Each map entry can enable or disable different parts of the selected map. The available options are: * **Use Pos** * **Use Rot** * **Use Custom Data** **Use Pos** enables position data. **Use Rot** enables rotation data. **Use Custom Data** enables mapped values that are not position or rotation. Custom Data can include: * zoom * focus * encoder values * axis values * other workflow-specific values {% hint style="info" %} Lens encoder values such as **Zoom** and **Focus** are handled as **Custom Data**. {% endhint %} #### Combining Multiple Maps Some workflows require more than one map. For example, one map may provide position and rotation, while another map provides zoom and focus values. In this case, add both maps to the Map List and enable only the required values from each map. Example: | Map Entry | Use Pos | Use Rot | Use Custom Data | Purpose | | ------------------- | ------: | ------: | --------------: | --------------------------------- | | Camera tracking map | on | on | off | Uses camera position and rotation | | Lens encoder map | off | off | on | Uses zoom and focus | {% hint style="warning" %} Avoid enabling the same type of data from multiple maps unless the workflow explicitly requires it. Duplicate position, rotation, or encoder values can lead to incorrect calibration results. {% endhint %} *** ## Select Workflow-Specific Objects Some workflows require additional project objects or existing calibration data. These options depend on the loaded calibration workflow. #### Camera Object Static calibration workflows and some repositioning workflows require a **Camera Object**. The Camera Object is the target that receives the calibration result or uses the generated profiles. #### Axis 2D Object Axis-Pole Calibration requires an **Axis 2D** object. The Calibration Object links to the Axis 2D object so the calibration can write the learned movement model into it. The Camera Object should be placed as a child of the Axis 2D object. #### Lens Profile Some workflows require an existing Lens Profile as an input. For example, Tracking Alignment and Alignment with Markers usually use an existing Lens Profile and only solve the tracking alignment. #### Alignment Profile Some workflows require an existing Alignment Profile as an input. For example, screen alignment or repositioning workflows may use an existing calibrated camera setup and update another part of the system. *** ## Configure Output Settings The Calibration Object can create different outputs depending on the selected workflow. These outputs are usually configured in the **User Outputs** section. #### Lens Profile Output Workflows that solve lens calibration can create a **Lens Profile**. Depending on the output settings, the result can be saved as a new profile, overwrite an existing profile, or be assigned directly to a Camera Object. #### Alignment Profile Output Tracking workflows can create an **Alignment Profile**. The Alignment Profile aligns the incoming tracking data with the real optical camera. #### Screen Reposition Output Some workflows can create or apply Calibration Screen reposition data. This can update the placement, orientation, or shape of Calibration Screens. {% hint style="warning" %} Only enable screen reposition output if the Calibration Screens should actually be updated. If these screens are already used in Unreal Engine, a media server, or another external system, changing them may require re-exporting or updating that system. {% endhint %} #### Axis 2D Output Axis-Pole Calibration writes calibrated movement data into the Axis 2D object. This allows the Axis 2D object to drive the child Camera Object using the calibrated 3D movement path. #### Camera Object Output Static calibration workflows can write values directly to the Camera Object. This can include camera transform values and lens-related values depending on the selected workflow. *** ## Check Before Opening the Capture Window Before opening the Capture Window, make sure the Calibration Object is fully configured. #### Required Inputs Check that all required inputs are assigned. Depending on the workflow, this may include: * Image input * Calibration Screens * Measurement Points * Camera Object * Axis 2D object * Lens Profile * Alignment Profile * Maps #### Map Data Check that the selected maps provide the required values. For moving camera workflows, make sure the expected values are updating: * position * rotation * zoom * focus * axis or movement values #### Calibration References Check that the required references are visible and correct. For Calibration Screens, make sure the correct Calibration Images are displayed. For Manual Marker workflows, make sure Measurement Points exist and are accurately measured. *** ## Open the Capture Window After the Calibration Object is configured, open the Capture Window.
The Capture Window is used to collect calibration samples, inspect image detection, monitor map data, and evaluate the solve status. {% hint style="info" %} The calibration process starts when the Capture Window is opened and Auto Calibrate is enabled. {% endhint %} *** ## Before Continuing Checklist Before opening the Capture Window, check the following: * The correct calibration workflow has been loaded. * The correct Media Input is selected in the **Image** field. * The image is the raw camera signal. * Calibration Screens or Measurement Points are assigned if required. * The Master Screen is selected if required. * The required maps are added in **Maps → Map List**. * Each **Input Map** points to the correct map. * **Use Pos**, **Use Rot**, and **Use Custom Data** are enabled only where needed. * The Camera Object is selected if required. * The Axis 2D object is selected if required. * Existing Lens Profiles or Alignment Profiles are selected if required. * Output settings are configured for the results you want to create. * Screen repositioning is enabled only if Calibration Screen placement should be updated.