← Back to slide 28The pharmacist and the generator
← All interactivesSame scene. Any order.
The model predicts a set of objects. Should it lose points just for listing them in a different order? Try it.
STEP 1 OF 3
Move the orange piece into target A.
Two objects already fit. Drag the orange disc onto the dashed circle, or use the button below.
◌ Dashed outline = target● Solid disc = prediction
Show the matching and the cost calculation
This flat puzzle uses |Δx| + |Δy| + 2(|Δmotion-x| + |Δmotion-y|), in scene units. The training model uses full 3D placement and motion vectors; this is a simplified 2D illustration.
The highlighted cells form the cheapest one-to-one assignment, found by checking all six pairings. Reordering rows cannot change that minimum.
Why this matters: a scene has no natural “first object.” The pharmacist's object queries predict placement and motion together. Assignment pairs the predictions with the true objects before computing their loss, so output order does not define object identity. The separate camera prediction is outside this object matching.