task_three_d__street__lane_ahead_object_label

Summary

• Domain: three_d
• Scene id: street
• Scene package: street
• Supported query_id: single
• Answer type: option_letter
• Annotation schema: bbox

Program Contract

Program: select(label(candidate_street_objects, predicate=same_lane_and_ahead_of_reference)); scene=street; scope=lane_ahead_object_label

Candidate set: the visible 3D objects, surfaces, room/street/warehouse structures, spatial anchors, markers, and labeled options inside the lane_ahead_object_label objective scope. Operands: visible scene state and prompt-bound operands named by label, candidate_street_objects, predicate, same_lane_and_ahead_of_reference, street, lane_ahead_object_label. Operation: evaluate select over the candidate set using the finalized 3D scene state, camera projection, object identities, spatial relations, counts, distances, or option-selection constraints encoded in the program expression; generation enforces a unique final answer. Output binding: answer uses the option_letter schema; generation binds a unique final answer. Annotation witnesses: annotation uses the bbox schema; the prompt/annotation contract defines the minimal visual witnesses. Query ids: single.

Reasoning Operations

Families: spatial_relations

Contract

The image shows a synthetic perspective 3D street intersection or T intersection with roads, sidewalks, crosswalk markings, unlettered street context, one red-boxed reference street object with a red travel-direction arrow, unlettered street-object candidates, and a below-scene text option panel.

Each instance renders 4 unlettered candidate street objects plus unlettered street context. The reference object is an unlettered car marked with a red bounding box and red direction arrow. Exactly one candidate is ahead of the reference along the same finalized lane corridor and travel direction. Distractors include objects behind the reference, objects ahead in an adjacent lane, objects off the lane, and objects on other present road arms.

The verifier uses finalized metadata, not pixels: reference road arm, lane id, travel direction vector, candidate forward distance from the reference, candidate lateral distance from the reference lane, and candidate road arm.

Annotation Contract

Annotation is the bounding box of the selected street object in the scene. The red reference box, red arrow, road markings, context objects, option panel, and option text are not annotation.

Prompt And Trace

The prompt bundle is three_d_street_v1 under src/trace_tasks/resources/prompts/three_d/street/. The trace records camera pose, projection frame, scene variant, intersection layout, present/missing road arms, travel mode, reference road arm/lane/direction, candidate road arms by label, forward and lateral lane distances by label, ahead flags by label, selected object id/type, projected object bboxes, and option-panel descriptors/bboxes.

Determinism

Generation is deterministic from instance_seed, explicit params, config defaults, prompt bundle, and code versions. Answers and annotation come from the same finalized 3D street scene trace.