Domain: Engineering — Network Engineering
Target concept: Ring Topology Network

Video generation prompt: Construct a ring topology network, connecting four switch nodes (marked in red) with blue circular links in sequence. Enable bidirectional communication between the nodes, and mark the data transmission direction with green optical points. Disconnect the link of one switch, observe the network communication status, mark the communication links with green blinking indicators, and indicate the interrupted link in gray.

Evaluation guide:
(i) Target concept: Fault-tolerant behavior of ring topology networks via automatic path rerouting upon single-link failure.
Minimum mechanism: A closed loop of four identically capable nodes with bidirectional logical channels; physical link failure interrupts only that segment while preserving alternative forwarding paths; visual indicators must distinguish active transmission (green optical points), active standby/monitoring (green blinking), and failed state (gray static segment).
(ii)Storyline: Frame sequence begins with static ring (four red switches + four blue links); then green optical points appear and move bidirectionally on all links; next, one blue link visibly fractures (clean break animation); immediately, that segment becomes solid gray and ceases all activity; simultaneously, green blinking indicators activate on all three remaining links; finally, green optical points continue traversing the alternate full loop (e.g., skipping the gray segment and flowing around the rest of the ring), confirming uninterrupted communication, all under fixed frontal viewpoint with no camera motion or object repositioning.

Manual:
Experimental Procedure
1. Place four switch nodes and mark each in red.
2. Connect them sequentially with blue circular links to form a closed ring.
3. Activate bidirectional data transmission: show green optical points moving clockwise and counterclockwise along all links.
4. Disconnect one blue link: show it breaking cleanly.
5. Immediately mark the broken link in gray and activate green blinking indicators on all remaining links.
Observation of Experimental Phenomena
- Four red switches arranged in a closed ring.
- Blue circular links fully connecting them before disconnection.
- Green optical points moving continuously in both directions on all links pre-disconnection.
- One blue link breaks and turns solid gray.
- Green blinking indicators appear exclusively on the three unbroken links post-disconnection.
Summary of Experimental Principles
Ring topology provides path redundancy: when one link fails, data reroutes bidirectionally through the remaining links, maintaining end-to-end connectivity.

Prompt Grounding rubric:
level_1: No ring topology network appears at all: zero switch nodes, no blue links, no red marking on switches, no green optical points, no disconnection event, no gray segment, and no blinking indicators are shown.
level_2: At least one red-marked switch node appears, and at least one blue link is present, but the four-switch ring structure is absent; green optical points or blinking indicator icons are missing entirely, or placed on objects that aren't links/switches; no disconnection event occurs; no gray segment appears anywhere.
level_3: All four required elements of the setup are present: four switch nodes marked in red; blue circular links connecting them into a closed ring; green optical points that appear and move along the links; and a disconnection event in which one link visibly breaks and is rendered as a distinct gray segment. Green blinking indicator markers, visually distinct from the steady green optical points, also appear on the network following the break; which specific links they land on is a communication-accuracy question judged under the science-correctness criteria, not here.
level_4: Everything required at the 3-point level holds, and in addition: the four red switches sit in a geometrically closed ring shape (not a line or branching layout); the blue links form one continuous, unbroken circle before the disconnection; the green optical points move continuously in both directions around the ring before the break; the disconnection produces exactly one gray segment, clearly located at a single, unambiguous link; and the green blinking indicator markers are rendered in a visually distinct style from the plain green optical points, so the two indicator types are never confused with each other.
level_5: Everything required at the 4-point level holds, and in addition: the ring layout is visually symmetric, with all four switches equal in size and evenly spaced; the blue links match each other in thickness, curvature, and color; the green optical points are uniform in size, brightness, and speed on every link they appear on; the blinking indicator markers share the same blink phase and duty cycle across whichever links they appear on; the gray segment has a sharp, clean edge with no partial transparency or color bleed; and no visual artifact, duplication, or mislabeling appears anywhere in the scene.

Scientific and Causal Correctness rubric:
level_1: No scientifically valid fault-tolerant behavior is shown: bidirectional communication is never indicated, no rerouting or path redundancy is demonstrated after the break, data flow direction contradicts how a ring works (e.g., only one direction ever shown, or motion is random), or the interruption causes total loss of activity everywhere instead of continued communication on the remaining path.
level_2: A ring-like shape appears, but the communication indicators contradict how a ring topology should behave: e.g., the green optical points move in only one direction; blinking indicators appear on the broken (gray) link; the gray link still shows active transmission; or nothing in the scene indicates that communication continues after the disconnection.
level_3: Before the disconnection, green optical points move in both directions on every link; after the disconnection, green blinking indicators appear only on the three links that are still connected between all four switches, and the gray link shows no blinking; communication is shown as remaining functional along the surviving path (every switch can still be reached via the remaining links); the gray link itself shows no ongoing transmission.
level_4: Everything required at the 3-point level holds, and in addition: the blinking indicators start on all three surviving links at essentially the same time, with none delayed or left out; every link (not just some) shows bidirectional optical-point motion before the disconnection; the gray link shows zero ongoing activity afterward (no flicker, glow, or residual motion on it).
level_5: Everything required at the 4-point level holds, and in addition: continued communication after the break is shown concretely: green optical points keep traveling the full remaining loop (e.g., Switch1 to Switch2 to Switch3 to Switch4 and back to Switch1) without gaps or reversing direction; no frame shows a contradiction, such as an optical point vanishing mid-link or blinking appearing on the gray segment; the sequence of cause and effect is unambiguous and in order: the break happens, the gray segment appears, optical-point motion on that segment stops, blinking starts on the remaining links, and optical points continue moving along the alternate path.

Spatiotemporal Consistency rubric:
level_1: Severe spatiotemporal breaks: a switch instantly appears in a new position between consecutive frames instead of the ring staying put; a blue link snaps into existence or vanishes without any connect/break animation; a green optical point jumps from one part of a link to another with no visible path between; the gray segment appears with no disconnection animation ever having played; the green blinking indicators flicker at randomly changing rates or disappear partway through the sequence for no shown reason.
level_2: Moderate breaks: one switch's position or size changes noticeably between shots; one blue link appears or disappears abruptly rather than fading in or visibly breaking; a green optical point skips over part of a link or reverses direction with no cause shown; the gray segment appears before any break animation has played; the green blinking indicators begin before the link has finished breaking.
level_3: The four switches stay in the same positions and at the same scale throughout; the blue links keep the same shape and connect the same pairs of switches at all times; the green optical points move smoothly along the links with no jumps or freezing; the disconnection is shown as a single clean break at one link (no stretching or fading out); the gray segment appears right after that break and stays visually unchanged afterward; the green blinking indicators only start once the break animation has fully finished, and once started, keep blinking steadily.
level_4: Everything required at the 3-point level holds, and in addition: the green optical points move at a matching, even speed and spacing on every link, both before and after the disconnection; every optical point stays visually aligned with the link it's traveling along, in every frame; the green blinking indicators on the three remaining links pulse with matching timing and brightness; the ring's shape, and each switch's orientation, stay the same throughout (no warping or rotation of any part of the network).
level_5: Everything required at the 4-point level holds, and in addition: every motion in the scene (optical points, the break, the color change to gray, the onset of blinking) unfolds as a gradual, continuous change rather than an instant cut or snap; no part of the ring is ever hidden behind another part or cut off at the frame edge; the background behind the ring stays fixed with no drift relative to the ring; the camera framing stays completely fixed, with no zooming, panning, or tilting at any point in the sequence.