> For the complete documentation index, see [llms.txt](https://docs.imerit-prod.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.imerit-prod.io/project-setup/create-recipe/2.-classes.md).

# 2. Classes

Define [new classes](#create-classes) and link them to a drawable from the right-highlighted section below. The saved classes will appear in rows highlighted on the left.

<figure><img src="/files/01IPzqAz9Do54qToeSH2" alt=""><figcaption></figcaption></figure>

## Create Classes

Provide the following details to create a new class:

### **Name**

* **Name**: Name of the class shown in the output data to be entered here.
* **Display Name**:  Class name displayed on the annotation tool to be entered here.
* **Abbreviated Name**: Define the short form of the *class* name which gets displayed in data columns with space constraint.

Based on the selection in Step 1 Basic Details, [Segmentation Mode](/project-setup/create-recipe/1.-basic-details.md#segmentation-mode), drawable tools will appear.

<figure><img src="/files/n97tciqBwuL6zXFW339t" alt=""><figcaption></figcaption></figure>

***

## **Geometry Drawing Tools**

Select the [drawing tools](/annotation-tool/drawing-tools.md) that need to be enabled for marking areas or points of the object falling under this class on the annotation tool. This is a multi-select option:

### **Polygon (3D)**

A **Polygon 3D** is an annotation tool that allows users to draw a closed shape in 3D space by connecting multiple points or vertices. These points (3 or more) are joined together to form a polygonal surface, typically used to annotate complex, irregularly shaped objects or surfaces within a point cloud.

[Learn how to use](/annotation-tool/drawing-tools/polygon-3d.md)

### **Polyline (3D)**

A **3D Polyline** is a flexible annotation tool that allows users to draw a continuous line in 3D space with a starting point, an endpoint, and an unlimited number of joints or nodes in between. Each node marks a point in space where the line changes direction, enabling annotators to outline complex shapes or paths.&#x20;

[Learn how to use](/annotation-tool/drawing-tools/polyline-3d.md)

### **Cuboid (3D)**

A **3D Cuboid** is a three-dimensional annotation tool used in point cloud and image data labeling to enclose objects within a cube-like shape. By specifying the length, width, and height of the cuboid, annotators can create a box around an object, helping to define its spatial dimensions and orientation in 3D space.

[Learn how to use](/annotation-tool/drawing-tools/cuboid.md)

#### **Dynamic Dimension**

This input appears only when the drawing tool selected is a **cuboid** and the [Has Instance](#has-instances) toggle is switched **ON**.&#x20;

* By indicating dimension as dynamic (toggle **ON**), a marked annotation for an object can vary in dimension across the sequence of [frames](/project-setup/pre-process-data.md#frame). With this feature, tracking a pedestrian from a sitting position to a standing position, becomes very easy.
  * [**Uniform Dimension**](/annotation-tool/key-features/unify-dimension.md) -  This feature takes the box size in the current [frame](/project-setup/pre-process-data.md#frame) and applies it to all [frames](/project-setup/pre-process-data.md#frame) (where the object is visible).&#x20;

{% hint style="success" %} <img src="/files/iAfqrynDsFkwpijZxywW" alt="" data-size="line"> Dynamic Dimension ON feature is best utilized when the annotator identifies the [frame](/project-setup/pre-process-data.md#frame) where the cuboid is most visible (containing the maximum points). Using it in such instances ensures a more efficient annotation process.
{% endhint %}

* By indicating dimension as non-dynamic (toggle **OFF**), a marked annotation's dimension for an object remains constant across the sequence of [frames](/project-setup/pre-process-data.md#frame). Any change in dimension would reflect across all its occurrences. With this feature, annotating a lamp post becomes easy.

<figure><img src="https://lh7-us.googleusercontent.com/docsz/AD_4nXfKlA_LSOIzcMtSnBRFWqZLd3luumFPFr1cGzNW6UObc6YofV2esVq8HJBV2bqNJI8jOcBjrzd0tkazlFcljYNLyFuK5wXg1zGSBDo85pgxtnOOovg5xVuELtYU-WNfiOrD3X63s1dGbp7qfkiGLpWJwO3j?key=lGhAQLv5xC3Ciuwf6zBTGQ" alt=""><figcaption></figcaption></figure>

#### **Preset Cuboid Dimension**

[Preset Cuboid Dimension](/annotation-tool/key-features/preset-cuboid-dimensions.md) toggle input appears only when the drawing tool selected is a **cuboid**.

* By indicating Preset Cuboid Dimension toggle **ON**, allows teams to define a standard cuboid size per class—particularly useful for objects with known and consistent dimensions.
* By indicating Preset Cuboid Dimension toggle **OFF**, a standard cube dimension is available.

<figure><img src="/files/JTCSIAVtaRyJav11OwaP" alt=""><figcaption></figcaption></figure>

### **Polygon (2D)**&#x20;

A **Polygon 2D** is an annotation tool used to draw a closed shape by connecting multiple points or vertices on a 2D plane, typically on an image. It allows users to outline irregular or complex objects with precision by placing a series of points around the object's boundary.

[Learn how to use](/annotation-tool/drawing-tools/polygon-2d.md)

### **Rectangle (2D)**

A **2D Bounding Box (BBox)** is a rectangular annotation tool used to enclose and label objects within a 2D image. It is defined by the top-left and bottom-right corners, creating a box that contains the object of interest.

[Learn how to use](/annotation-tool/drawing-tools/rectangle.md)

The following 3 inputs appear when the drawing tool has rectangle selected:

#### **Truncate**

If the rectangle extends beyond the image edge, it auto-truncates by snapping back to the edge. When this option is OFF, dimensions remain unchanged even if part of the rectangle lies outside the image.

#### **Keypoint with Vertical Line**

A line appears in the centre of the rectangle, enabling the marking of a key point within a rectangle.

Learn how to use the [keypoint with vertical line](/annotation-tool/drawing-tools/rectangle.md#key-point-with-vertical-line) within the rectangle.

#### **Edge Length Constraint:**

Add minimum and maximum dimension limits for the rectangle belonging to a class.

<figure><img src="https://lh7-us.googleusercontent.com/docsz/AD_4nXcAn0K4u_7flGhAEDInHIX9r0JEXY-0BxCCARVNNxXNsZT9HCU8E0zMYRnys1_GT2bjNkptnNgKxmZy-rlQzsZ8z-fcMrhQP3N3lcFNurGva1wtU7Vqa_1D3qKJOVJGl90e2-QT1tWcBand2Ts1uQdNhXJK?key=lGhAQLv5xC3Ciuwf6zBTGQ" alt=""><figcaption></figcaption></figure>

### **Polyline (2D)**

A **Polyline 2D** is an annotation tool used to draw a series of connected straight lines (segments) on a 2D image. It consists of multiple points (or nodes) that define the shape, allowing annotators to mark irregular or elongated objects with more precision than a simple bounding box.

[Learn how to use](/annotation-tool/drawing-tools/polyline-2d.md)

***

## **Has Instances**

Instance Tracking should be toggled **ON** to enable object tracking when multiple objects of the same class appear within a [frame](/project-setup/pre-process-data.md#frame). Each object instance is assigned a unique identifier for differentiation. For example, the class 'Car' will have multiple instances such as car\_1, car\_2, car\_3, whereas a class like 'Vegetation' may typically be represented as a single instance encompassing the entire [frame](/project-setup/pre-process-data.md#frame).

***

## **Color**

Color to be represented for the annotation after marking it with the drawing tool. Users can select from the color picker or provide a HEX code.

***

## Segmentation Drawing Tools

### Brush Sphere

**Paintbrush 3D** is a tool used in 3D point cloud annotation that allows annotators to "paint" over specific areas of the 3D space.&#x20;

[Learn how to use](/annotation-tool/drawing-tools/brush-sphere.md).