Class InstanceIdToColorMapping
Static class to procedurally generate a unique color for an instance ID. This algorithm is deterministic, and will always return the same color for a ID, and the same ID for a color. ID 0 is reserved to be an invalid ID and is mapped to color black (0,0,0,255). Invalid IDs always map to black, and black always maps to ID 0. In order to try to create visually contrasting colors for IDs, there are a subset of IDs reserved (1-65) to be generated by applying the golden ration to find the next color in the HSL spectrum. All of these colors, and only theses colors, will be in the alpha channel 255. After the first 65 IDs, the color will be determined by iterating through all available RGB values in the alpha channels from 264 - 1. Alpha channel 0 is marked as invalid. This service will support over 4 billion unique IDs => colors [(256^4) - (256*2) + 64]
Namespace: UnityEngine.Perception.GroundTruth
Syntax
public static class InstanceIdToColorMapping : objectFields
invalidColor
The color returned when an instanceId is not mapped to any color, and for clearing ground truth material properties on a
Declaration
public static readonly Color32 invalidColorField Value
| Type | Description |
|---|---|
| Color32 |
maxId
The max ID supported by this class.
Declaration
public const uint maxId = nullField Value
| Type | Description |
|---|---|
| UInt32 |
Methods
GetColorFromInstanceId(UInt32)
Retrieve the color that is mapped to the passed in ID. If the ID is 0 or 255 the returned color will be black.
Declaration
public static Color32 GetColorFromInstanceId(uint id)Parameters
| Type | Name | Description |
|---|---|---|
| UInt32 | id | The ID of interest. |
Returns
| Type | Description |
|---|---|
| Color32 | The color associated with the passed in ID, or black if no associated color exists. |
GetColorFromPackedColor(UInt32)
Converts a packed color (or unsigned 32bit representation of a color) into an RGBA color.
Declaration
public static Color32 GetColorFromPackedColor(uint color)Parameters
| Type | Name | Description |
|---|---|---|
| UInt32 | color | The packed color |
Returns
| Type | Description |
|---|---|
| Color32 | The RGBA color |
GetInstanceIdFromColor(Color32)
Retrieve the ID associated with the passed in color. If the passed in color is black this service will return 0.
Declaration
public static uint GetInstanceIdFromColor(Color32 color)Parameters
| Type | Name | Description |
|---|---|---|
| Color32 | color | The color to map to an ID. |
Returns
| Type | Description |
|---|---|
| UInt32 | The ID for the passed in color. |
GetPackedColorFromColor(Color32)
Packs a color32 (RGBA - 1 byte per channel) into a 32bit unsigned integer.
Declaration
public static uint GetPackedColorFromColor(Color32 color)Parameters
| Type | Name | Description |
|---|---|---|
| Color32 | color | The RGBA color. |
Returns
| Type | Description |
|---|---|
| UInt32 | The packed unsigned int 32 of the color. |
TryGetColorFromInstanceId(UInt32, out Color32)
Retrieve the color that is mapped to the passed in ID. If the ID is 0 or 255 false will be returned, and color will be set to black.
Declaration
public static bool TryGetColorFromInstanceId(uint id, out Color32 color)Parameters
| Type | Name | Description |
|---|---|---|
| UInt32 | id | The ID of interest. |
| Color32 | color | Will be set to the color associated with the passed in ID. |
Returns
| Type | Description |
|---|---|
| Boolean | Returns true if the ID was mapped to a non-black color, otherwise returns false |
TryGetInstanceIdFromColor(Color32, out UInt32)
Retrieve the ID associated with the passed in color. If the passed in color is black or cannot be mapped to an ID this service will return false, and the out id will be set to 0.
Declaration
public static bool TryGetInstanceIdFromColor(Color32 color, out uint id)Parameters
| Type | Name | Description |
|---|---|---|
| Color32 | color | The color to map to an ID. |
| UInt32 | id | This value will be updated with the ID for the passed in color. |
Returns
| Type | Description |
|---|---|
| Boolean | This service will return true if an ID is properly mapped to a color, otherwise it will return false. |