Generate Euro NCAP Variants

Create Euro NCAP seed scenarios, generate variants, translate between simulators, plot descriptors, and compute scores using the ADT Euro NCAP support package APIs.

When to Use

• Creating Euro NCAP seed scenarios (any protocol year)
• Generating scenario variants from seeds
• Translating scenarios between drivingScenario and RoadRunner via descriptors
• Plotting scenario descriptors (single or multi-descriptor grids)
• Computing NCAP scores and generating/exporting reports
• Any workflow mentioning Euro NCAP test names (CCRs, CCFtap, CCCscp, CPNA, etc.)

When NOT to Use

• Building custom drivingScenario from scratch (roads, lanes, actors) — use drivingScenario core APIs directly
• RoadRunner scene/project management (creating projects, importing assets) — use RoadRunner scene APIs
• Custom variationProperties for non-NCAP scenarios
• Simulink co-simulation or AEB test bench setup

Decision Tree: Which API Path?

User wants Euro NCAP scenarios?
│
├─ Protocol year 2023 (or unspecified)?
│   └─ Use standalone: ncapScenario("SA AEB CCFtap")
│      - Test names use prefix: "SA AEB", "SA LSS", "VRU AEB", "VRU LSS"
│      - Supports ShowProgress name-value
│      - Returns ScenarioDescriptor
│
└─ Protocol year 2026?
    └─ Use euroAssessment path:
       1. ea = euroAssessment(2026)
       2. configureVUT(ea, ...) — if custom VUT needed
       3. descriptor = ncapScenario(ea, "CA FC CCFtap")
       - Test names use prefix: "CA FC"
       - Does NOT support ShowProgress
       - Required for scoring/reporting workflow

Key Functions

Function	Purpose	Available From
ncapScenario	Generate seed descriptor(s) from test name	R2024a
euroAssessment	Store 2026 protocol specs and scores	R2025a
configureVUT	Set StabilizationTime, AssetPath on euroAssessment	R2026a
getScenario	Convert descriptor → drivingScenario or RoadRunner	R2022b
getScenarioDescriptor	Extract descriptor from existing drivingScenario	R2022b
generateVariants	Generate variant descriptors from seed + variationProperties	R2023a
plot (ScenarioDescriptor)	Plot descriptor(s), returns ScenarioDescriptorPlot	R2026a
configure (ScenarioDescriptorPlot)	Set GridSize, Title, SubPlotTitles, CropType	R2026a
assessmentTable	Create empty assessment table for a test	R2025a
ncapScore	Compute score from assessment table (returns struct)	R2025a
ncapReport	Generate visual report figure	R2025a
exportReport	Export report to PDF/PNG/JPG file	R2026a
table2scenario	Create ScenarioDescriptor from tabular data (sceneSpec, actorSpec, eventSpec)	R2024a
exportScenario (roadrunner)	Export from RoadRunner to OpenSCENARIO	R2022a

Pattern: Seed-Only Generation

Use when you need just the seed scenario (1 descriptor), not all variants.

% 2023 standalone — single seed
descriptor = ncapScenario("SA AEB CCFtap");

% 2026 via euroAssessment — single seed
ea = euroAssessment(2026);
descriptor = ncapScenario(ea, "CA FC CCFtap");

AllScenarios=true generates the seed AND all protocol-defined variants. Do NOT use it when only the seed is requested.

Output arguments: The two-output form [descriptors, scenarioInfo] = ncapScenario(...) requires AllScenarios=true. Without it, only one output is allowed — requesting two outputs errors with "Too many output arguments".

Pattern: All Variants Generation

Use when the user wants all test variants for a given scenario.

% 2023 — all variants with progress
[descriptors, scenarioInfo] = ncapScenario("SA AEB CCCscp", AllScenarios=true);

% 2026 — all variants
ea = euroAssessment(2026);
[descriptors, scenarioInfo] = ncapScenario(ea, "CA FC CCCscp", AllScenarios=true);

Pattern: ShowProgress

The ShowProgress name-value controls built-in progress display during generation.

% Show command-line progress (default behavior)
descriptor = ncapScenario("SA AEB CCRs", ShowProgress="CommandLine");

% Suppress progress
descriptor = ncapScenario("SA AEB CCRs", ShowProgress="No");

Important: ShowProgress is only supported on the standalone ncapScenario(testName) call. It is NOT supported when using the euroAssessment overload ncapScenario(ea, testName).

When the user asks to "show progress" or "display progress", use ShowProgress="CommandLine" (or omit it since it's the default). Do NOT set ShowProgress="No" and then implement manual fprintf progress.

Pattern: DSD ↔ RoadRunner Translation

Use getScenario to translate a descriptor to either simulator. Never export to OpenSCENARIO and re-import as a translation method.

% Descriptor → drivingScenario
ds = getScenario(descriptor, Simulator="DrivingScenario");

% Descriptor → RoadRunner (requires active RoadRunner instance)
rrApp = roadrunner("C:/path/to/project");
rrScen = getScenario(descriptor, Simulator="RoadRunner", SimulatorInstance=rrApp);

Key rules:

• getScenario requires Name-Value syntax. Simulator must be specified as a Name-Value pair, not a positional argument.
• With Simulator="DrivingScenario": accepts an array of descriptors and returns an array of drivingScenario objects.
• With Simulator="RoadRunner": accepts only a single descriptor per call — returns one Simulink.ScenarioSimulation object. Passing an array errors with "Too many input arguments". Loop over descriptors individually for batch RoadRunner translation.

Pattern: ScenarioDescriptorPlot

Configure options

Property	Values	Notes
GridSize	[rows cols], max product = 20	Error if > 20 subplots
Title	string	Figure title
SubPlotTitles	string array	Must match descriptor count exactly
CropType	"None", "GlobalWaypoint", "DynamicWaypoint", "RuntimeActorsCrop"	Controls plot cropping

Single or small array (≤20 descriptors)

sdp = plot(descriptors);
configure(sdp, Title="My Scenarios", GridSize=[3 4], ...
    SubPlotTitles=["Variant 1", "Variant 2", "Variant 3"]);

Large array (>20 descriptors)

ScenarioDescriptorPlot supports a maximum of 20 subplots per figure via GridSize. For larger arrays, split across multiple calls:

% Plot first 20
sdp1 = plot(descriptors(1:20));
configure(sdp1, Title="Variants 1-20", GridSize=[4 5]);

% Plot remaining
sdp2 = plot(descriptors(21:end));
configure(sdp2, Title="Variants 21-30", GridSize=[2 5]);

Play/seek for animation

sdp = plot(descriptor);
play(sdp);          % Animate the scenario
seek(sdp, 2.5);    % Jump to t=2.5s
close(sdp);        % Close figure

Pattern: 2026 Full Pipeline (Score + Report)

% 1. Create assessment object
ea = euroAssessment(2026);

% 2. Configure VUT (optional)
configureVUT(ea, StabilizationTime=2, AssetPath="Vehicles/SK_SUV.fbx");

% 3. Generate all variants
[descriptors, scenarioInfo] = ncapScenario(ea, "CA FC CCFtap", AllScenarios=true);

% 4. Create assessment table and populate results
% Column names are test-dependent — inspect with at.Properties.VariableNames
% Common columns: ImpactVelocity (CCFtap, CCCscp) or RelativeImpactVelocity (CCRs, CCRm, CCRb)
at = assessmentTable(ea, "CA FC CCFtap");
at.ImpactVelocity = zeros(height(at), 1);  % Replace with actual sim results

% 5. Compute score (returns struct, not scalar)
[score, updatedTable] = ncapScore(ea, "CA FC CCFtap", at);
fprintf("Total score: %.2f / %.2f\n", score.AggregateScore.Total, score.AvailableScore.Total);

% 6. Generate report figure
fig = ncapReport(ea, "CA FC CCFtap");

% 7. Export report to file
exportReport(ea, "CA FC CCFtap", "ncap_report.pdf");

Pattern: table2scenario (Custom Descriptors from Tables)

Use table2scenario to create a ScenarioDescriptor from user-defined tabular data. This is the programmatic entry point when you have scenario parameters in table form rather than using the predefined NCAP test definitions.

% Scene: straight road, 100m
sceneSpec = table(1, {'Straight'}, 100, 0, NaN, ...
    VariableNames=["RoadElementID", "RoadElementType", "Length_Radius", ...
                   "DeltaHeading", "ParentIntersectionID"]);

% Actor: one car (Ego) on road 1, lane 1
actorSpec = table(1, 1, 1, {'Car'}, {'Ego'}, ...
    {'4.7, 1.8, 1.4, 0.5, 0.9, 2.8'}, {'Along'}, {'10%, 50%'}, ...
    VariableNames=["ActorID", "RoadID", "LaneID", "ActorType", ...
                   "ActorName", "Dimension", "Heading", "RelativePosition"]);

% Event: fixed velocity start at 15 m/s
eventSpec = table(1, 1, {'FixedVelocityStart'}, 15, NaN, NaN, ...
    VariableNames=["EventID", "ActorID", "EventType", "Speed", ...
                   "Distance", "EventTrigger"]);

descriptor = table2scenario(sceneSpec, actorSpec, eventSpec);

Key rules:

• sceneSpec columns: RoadElementID, RoadElementType, Length_Radius, DeltaHeading, ParentIntersectionID
• actorSpec columns: ActorID, RoadID, LaneID, ActorType, ActorName, Dimension, Heading, RelativePosition
• eventSpec columns: EventID, ActorID, EventType, Speed, Distance, EventTrigger
• Returns a ScenarioDescriptor — same type as ncapScenario output
• The returned descriptor works with all downstream APIs: getScenario, plot, generateVariants
• Used internally by the NCAP pipeline; users can call it directly for custom (non-NCAP) scenarios

Pattern: OpenSCENARIO Export with Rear Axle

% Configure export options
opts = openScenarioXMLExportOptions(RelocateVehicleOrigin=true);

% Export from RoadRunner
exportScenario(rrApp, "output.xosc", "OpenSCENARIO XML", opts);

See references/export-options.md for full export configuration details.

Test Name Conventions

Critical: Euro NCAP test names must be specified in full. Short names like "CCFtap" or "CCCscp" are NOT valid.

Protocol	Prefix Pattern	Example
2023 standalone	"SA AEB ...", "SA LSS ...", "VRU AEB ...", "VRU LSS ..."	"SA AEB CCFtap"
2026 euroAssessment	"CA FC ..."	"CA FC CCFtap"

The short code (e.g., CCFtap, CCCscp, CCRs) is always the LAST part of the full name.

See references/ncap-test-names.md for the complete lookup table of all valid test names.

Common Mistakes

Mistake	Why It's Wrong	Correct Approach
ncapScenario("CCFtap")	Short names are not valid	ncapScenario("SA AEB CCFtap")
ncapScenario("SA AEB CCFtap") for 2026	Wrong prefix for 2026 protocol	ncapScenario(ea, "CA FC CCFtap") with ea = euroAssessment(2026)
getScenario(d, "RoadRunner")	Positional arg not supported	getScenario(d, Simulator="RoadRunner", SimulatorInstance=rrApp)
Setting ShowProgress="No" then using fprintf	Defeats built-in progress	Omit ShowProgress (default is "CommandLine") or set ShowProgress="CommandLine"
Using AllScenarios=true for seed-only	Generates all variants unnecessarily	Omit AllScenarios for seed only
DSD export → OpenSCENARIO → importScenario for RR	Roundabout, breaks pedestrians	getScenario(d, Simulator="RoadRunner", SimulatorInstance=rrApp)
Inventing VUTType or NcapYear params	These don't exist	Use configureVUT(ea, AssetPath=...) and euroAssessment(2026)
ShowProgress with euroAssessment overload	Not supported on that overload	Only use with standalone ncapScenario(testName)
[d, info] = ncapScenario(ea, name) without AllScenarios	"Too many output arguments" error	Use single output for seed, or add AllScenarios=true for two outputs
configureVUT called AFTER ncapScenario	Silently has no effect — config not applied	Always call configureVUT BEFORE ncapScenario
SubPlotTitles count ≠ descriptor count	"Invalid size of subplot titles" error	Provide exactly one title per descriptor
CropType="tight" or other invented values	Invalid value error	Use: "None", "GlobalWaypoint", "DynamicWaypoint", or "RuntimeActorsCrop"
plot(descriptors) with GridSize > [4 5]	Max 20 subplots per figure	Split array into chunks of ≤20
fprintf("%.2f", score) after ncapScore	score is a struct, not scalar	Access score.AggregateScore.Total for the numeric value
exportReport(ea, name, "report.html")	HTML not supported	Use .pdf, .png, or .jpg extension
at.ImpactVelocity = ... for CCRs/CCRm/CCRb tests	Column is RelativeImpactVelocity, not ImpactVelocity	Check at.Properties.VariableNames after assessmentTable — use the actual column name
getScenario(descriptors, Simulator="RoadRunner", ...) with array	RoadRunner only accepts one descriptor at a time	Loop: for i=1:numel(descriptors), getScenario(descriptors(i), ...); end

Conventions

• Always use full test names — never abbreviate
• Use euroAssessment(2026) for any 2026-protocol workflow (scoring, reporting, configureVUT)
• Use standalone ncapScenario(testName) for simple 2023 generation without scoring
• Use getScenario for ALL simulator translations — never export+reimport
• Use exportReport (R2026a) for file export — do not write custom report export code
• Use exportScenario (roadrunner method) for OpenSCENARIO export from RoadRunner
• Set RelocateVehicleOrigin=true in export options when rear axle reference is needed

Required Toolboxes

• Automated Driving Toolbox (R2026a)
• Automated Driving Toolbox Test Suite for Euro NCAP Protocols (support package, R2024a+)

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