lidar-solid-state-rays-per-line

Code	LI.004
Tags	✅

Summary

For solid-state OmniLidar prims, the sum of all elements in omni:sensor:Core:numRaysPerLine must equal omni:sensor:Core:numberOfEmitters.

Description

Solid-state LiDARs (omni:sensor:Core:scanType = "SOLID_STATE") use a fixed 2-D array of emitters organised into lines. The attribute omni:sensor:Core:numRaysPerLine declares how many emitters fire on each line. The total number of emitters across all lines must equal the value of omni:sensor:Core:numberOfEmitters.

This constraint is enforced by LidarCoreSensorCheckerImpl::validateNumRaysPerLine in the RTX sensor plugin, which is applied only for solid-state scan types.

This requirement does not apply to rotary lidars (scanType = "ROTARY"), which do not use the numRaysPerLine attribute.

Why is it required?

A mismatch between the declared number of emitters and the sum of rays per line means the sensor runtime cannot construct a consistent emitter layout. The simulation will reject the configuration at startup with a runtime error. Catching this at asset validation time makes the failure visible before any simulation is run.

Examples

# Valid: numberOfEmitters = 4, numRaysPerLine = [2, 2], sum = 4
def OmniLidar "Lidar" (
    prepend apiSchemas = ["OmniSensorGenericLidarCoreAPI"]
)
{
    token omni:sensor:Core:scanType = "SOLID_STATE"
    uint omni:sensor:Core:numberOfEmitters = 4
    uint omni:sensor:Core:numberOfLines = 2
    uint[] omni:sensor:Core:numRaysPerLine = [2, 2]
}

# Invalid: numberOfEmitters = 4 but sum(numRaysPerLine) = 3
def OmniLidar "Lidar" (
    prepend apiSchemas = ["OmniSensorGenericLidarCoreAPI"]
)
{
    token omni:sensor:Core:scanType = "SOLID_STATE"
    uint omni:sensor:Core:numberOfEmitters = 4
    uint omni:sensor:Core:numberOfLines = 2
    uint[] omni:sensor:Core:numRaysPerLine = [1, 2]
}

How to comply

Ensure sum(numRaysPerLine) == numberOfEmitters. If the sensor has N emitters divided equally across L lines, set numRaysPerLine to an array of L elements each with value N / L. Non-uniform distributions are supported as long as the total is exactly numberOfEmitters.