Interactive · the tracing half of the task

Trace it yourself

Grounding asks a model to find the referent and then trace it. Here the referent is already given to you — this is only the second half, and it is still hard. Place exactly N vertices around the shaded region. Your contour is rasterised and scored against the canonical exact-N target by the same policy the benchmark uses.

uid 0417 · “the zebra behind the fence”
8 vertices remainingclick to place
Referent
Budget
Referent region Canonical target GN Your polygon
IoU × 100 vs GN

Place all N vertices to score. Start point and direction are free — filled-mask IoU is invariant to cyclic shift and reversal.

exact length simple polygon positive area distinct vertices
You vs the hosted configurations at this budget

Model scores are the paper's fixed-denominator IoU² over 1,500 real RefCOCO-family questions. Yours is one synthetic contour with the referent already revealed — a generous comparison, and the point of the exercise.

response · 2N integers