> 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/spatial-interactive-experiences/building-an-interactive-tracking-project/define-the-tracking-area.md). # Define the Tracking Area Once the sensors are combined inside the Point Cloud Volume, the next step is to define which parts of the environment should actually participate in tracking. The goal is to remove as much permanent environment geometry as possible before filtering and clustering begin. Typical geometry that should not become part of the tracking data includes: * Walls * Ceilings * Pillars * Platforms * Furniture * Scenic or architectural structures The tracking area is defined using **Include** and **Exclude** geometry inside the Point Cloud Volume. A practical setup usually starts with one large Include region and is then refined using additional Includes and Excludes. *** ## Enable the Tracking Area The tracking-area clipping inside a new Point Cloud Volume is disabled by default. To enable it: 1. Select the **Point Cloud Volume** in the Project Tree. 2. Open **Pipeline** in the Inspector. 3. Enable the tracking-area / clipping container.
Once enabled, objects assigned to the Include and Exclude lists can control which points remain active. *** ## Choose the Tracking Geometry Include and Exclude regions are not limited to Cube Objects. They can be defined using different types of geometry, including: * Grid Studio primitives such as **Cube** * **Sphere** * **Cylinder** * Other suitable primitive objects * Imported mesh objects This makes it possible to approximate irregular tracking areas or permanent structures more closely than with rectangular volumes alone. {% hint style="info" %} Imported meshes can be used for Include and Exclude geometry. Referenced meshes are currently not supported for this purpose. {% endhint %} For this guide, we use Cubes because they are quick to create, easy to position, and suitable for many architectural environments. *** ## Create the First Include Volume For a typical rectangular room, a **Cube** is often the easiest geometry to start with. ### Add a Cube 1. Right-click an empty area of the **Project Tree**, or click the **+** button. 2. Search for **Cube**. 3. Add it to the project.
Before using the Cube for clipping, change its appearance so that it does not hide the point cloud. ### Display the Cube as a Wireframe Select the Cube and open **Display** in the Inspector. Under **Appearance**: * Disable **Fill** * Enable **Border**
The Cube is now displayed as a wireframe. You can additionally use: * **Border Color** to change the wireframe color * **Border Size** to change the thickness of the wireframe {% hint style="info" %} Using wireframe geometry is strongly recommended for tracking-area setup. A filled object can visually hide the point cloud that you are trying to inspect. {% endhint %} *** ## Add the Geometry to the Include List Position the Cube approximately around the area that should remain active.
Then: 1. Select the **Point Cloud Volume**. 2. Open **Pipeline** in the Inspector. 3. Drag the Cube from the **Project Tree** directly onto the **Include** list. As soon as the Cube is assigned, only points inside the Include geometry remain active.
This is the first point in the setup where the live point cloud may change dramatically. *** ## Use the VBO Snapshots as a Reference The VBO Snapshots created earlier now become particularly useful. The live point cloud only shows the measurements that are still part of the active tracking area, while the snapshots continue to show the original environment. Enable the VBO Snapshot for each sensor.
Then configure the live Sensor Objects so that the active data is clearly distinguishable from the static reference: 1. Set the live Sensor Objects to a **white** point-cloud color. 2. Set their **Point Size** to approximately **3**. 3. Keep the previously created VBO Snapshots visible in their original sensor colors.
The Viewport now provides two visual layers: * **Colored VBO Snapshots** — the original environment and sensor coverage * **White live points** — the point data that is currently active inside the Point Cloud Volume This makes it much easier to see exactly what is being kept or removed while editing the tracking area. {% hint style="success" %} This is one of the main reasons for creating VBO Snapshots before starting the tracking-area setup. They provide a permanent spatial reference even after the live point cloud has been heavily reduced. {% endhint %} *** ## Shape the Include Volume Use the **Viewport handles** to resize and position the Cube instead of changing its overall dimensions only through the Inspector. For this step, use the Viewport in **World** orientation and the appropriate move/edit mode. When the Cube is selected, a yellow handle appears in the center of each face. Drag a face handle to extend or reduce the Cube in that direction. Hold ALT while dragging a face handle to scale the Cube along that axis in both directions at the same time. Start by including as much of the useful tracking space as possible. The first Include does not need to perfectly avoid every permanent object. The goal is to establish the main usable volume of the environment.
*** ## Decide What to Include and What to Exclude As you shape the tracking area, permanent structures may still remain inside the Include volume. For example: * A pillar may stand in the center of the room * A platform may extend into the active area * Furniture may be located inside the otherwise useful tracking space There are two ways to handle these situations. You can shape the Include volumes around unwanted geometry, or keep the larger useful area and remove the unwanted structure later with an Exclude volume. Choose whichever produces the simplest and most maintainable tracking geometry. For example, it is often easier to keep one large Include volume for a room and place a smaller Exclude Cube around a pillar than to construct several complicated Include volumes around it. *** ## Do Not Over-Tune the Floor Yet It is useful to keep the floor approximately outside the active tracking area, but do not spend excessive time trying to remove every floor measurement using Include geometry alone. A dedicated floor-processing filter is available later in the pipeline and can handle remaining floor points more effectively. {% hint style="info" %} Use the tracking-area geometry to establish the main spatial boundaries of the installation. Detailed point cleanup is handled later during point-cloud filtering. {% endhint %} *** ## Extend the Tracking Area with Additional Includes A single object does not have to describe the entire tracking area. If the installation contains several connected or irregular regions, create additional geometry and add it to the **Include** list. For each additional area: 1. Add another primitive or imported mesh. 2. Configure its Viewport appearance if necessary. 3. Position and resize it in the Viewport. 4. Drag it into the **Include** list of the Point Cloud Volume.
The resulting tracking area is the combination of all configured Include regions. This is often easier than trying to represent a complex environment with one large object. *** ## Organize the Tracking Geometry Before adding more Include and Exclude geometry, it is useful to organize the tracking-area objects in the Project Tree. A simple structure could look like this: * **Point Cloud Volume** * Sensors * **Tracking Area** * Include geometry * **Occluders** * Exclude geometry The exact folder names and structure are up to you. The important part is to keep the geometry used for the tracking area clearly separated from the rest of the project. ### Use Folders as Include and Exclude References Folders are not only useful for keeping the Project Tree organized. Instead of adding every individual geometry object to the **Include** or **Exclude** list, you can reference a Folder itself. All geometry contained below that Folder is then used by the corresponding list. For example: 1. Add a **Folder** and name it `Tracking Area`. 2. Add another Folder and name it `Occluders`. 3. Move all Include geometry below `Tracking Area`. 4. Move all Exclude geometry below `Occluders`. 5. Drag the `Tracking Area` Folder onto the **Include** list of the Point Cloud Volume. 6. Drag the `Occluders` Folder onto the **Exclude** list.
This keeps the Point Cloud Volume configuration compact even when the project contains many individual clipping objects. Instead of maintaining a long list of references, the Point Cloud Volume may only need two: **Include → Tracking Area Folder** **Exclude → Occluders Folder** Additional geometry can then simply be added below the appropriate Folder. {% hint style="warning" %} When using a Folder as an Include or Exclude reference, enable **Use Children** for that reference. Without **Use Children**, only the Folder itself is referenced and the geometry contained below it is not included in the tracking-area calculation. {% endhint %}
### Keep the Tracking Geometry with the Point Cloud Volume It is also recommended to make the tracking-area Folders children of the **Point Cloud Volume**. This keeps the complete tracking setup spatially together. If the Point Cloud Volume is moved or transformed later, its Include and Exclude geometry moves with it instead of remaining behind in the project space. {% hint style="success" %} For larger projects, organize Include and Exclude geometry through Folders and place those Folders below the Point Cloud Volume. This keeps the Project Tree clean, reduces the number of individual references in the Pipeline, and ensures that the tracking geometry remains spatially attached to the Point Cloud Volume. {% endhint %} *** ## Remove Permanent Geometry with Excludes Use **Exclude** geometry for permanent structures that lie inside an otherwise useful tracking area. The workflow is the same as for Includes. For example, to remove a pillar: 1. Add another Cube or suitable geometry. 2. Display it as a wireframe. 3. Position it around the pillar. 4. Make the geometry slightly larger than the physical structure. 5. Drag it into the **Exclude** list of the Point Cloud Volume. Points inside the Exclude region are removed from the active tracking data.
Exclude regions take priority when they overlap with an Include region. This makes it possible to define a large usable tracking volume first and then cut permanent structures out of it. *** ## Geometry-Based and Automatic Occlusion Manually defined Include and Exclude geometry is not the only way to remove static environment data. Grid Studio also provides filtering approaches that can derive occlusion information from the point cloud itself. Depending on the processing setup, this can include methods that: * Detect persistent or changing regions in the point cloud * Use a previously captured point-cloud snapshot as an occlusion reference These methods can significantly reduce the amount of manually modeled Include and Exclude geometry required for an installation. However, their effectiveness depends strongly on the quality and consistency of the sensor data. If a sensor produces a stable and repeatable point cloud, automatic occlusion methods can provide a fast way to remove static environment geometry. If the point cloud is noisy, changes significantly between frames, or does not consistently return the same surfaces, manually defined geometry is usually the safer and more predictable approach. {% hint style="success" %} For installations where reliable and deterministic tracking is more important than minimizing setup time, explicitly defined Include and Exclude geometry provides the most controlled result. {% endhint %} Automatic occlusion and background-removal methods are covered in more detail in the **Point Filters** reference. *** ## Refine the Area Iteratively Continue adding and adjusting Include and Exclude geometry until the live point cloud contains primarily the space in which meaningful interaction can occur. A typical room may use: * One large Cube for the main Include area * Additional Include objects for extensions or irregular sections * Excludes around pillars * Excludes around platforms * Excludes around furniture or other permanent structures Keep the colored VBO Snapshots visible while adjusting the white active point cloud. This allows you to continuously compare: **Original environment → Active tracking data** Do not try to remove every noisy or isolated point at this stage. The tracking-area geometry should primarily remove large, predictable parts of the environment. Fine cleanup comes next during point-cloud filtering.
*** ## Verify the Tracking Area Before continuing, inspect the complete environment from several viewing angles. Verify that: * All areas where interaction should occur remain active. * Large permanent structures have been removed where practical. * Walls and ceilings are outside the active tracking volume. * Remaining floor points are limited to a manageable amount. * Important sensor coverage has not accidentally been clipped. * Overlapping Include and Exclude geometry behaves as expected. * The VBO Snapshots still provide a clear reference to the complete environment. The active point cloud should now represent the useful physical space of the installation rather than the complete environment seen by the sensors. Continue with **Clean the Point Cloud**.