Domain: Engineering — Chemical Engineering
Target concept: Coating Corrosion Protection

Video generation prompt: Take three identical metal specimens, each coated with an epoxy resin coating, an alkyd resin coating, and the third one uncoated, respectively. Place them simultaneously into a salt spray test chamber, set the spray pressure to 0.1 MPa, and spray a 5% sodium chloride solution for a continuous period of 24 hours.

Evaluation guide:
(i) Target concept: Coating efficacy hierarchy in corrosive environments under accelerated testing.
Minimum mechanism: Chloride ions induce electrochemical oxidation of iron; protective coatings inhibit ion transport; epoxy has lower permeability than alkyd; uncoated metal has no barrier.
(ii)Storyline: Frame 1–2: Static wide shot showing three identical metal specimens side-by-side, labeled or visually distinguished by surface finish (glossy/semi-gloss/bare). Frame 3–5: Salt spray chamber enclosure becomes visible; mist emerges uniformly and simultaneously toward all three specimens. Frame 6–8: Progressive appearance of reddish-brown discoloration *only* on uncoated specimen, followed by sparse brown patches *only* on alkyd specimen, while epoxy remains pristine. Frame 9–10: Final freeze showing sustained contrast: uncoated (rust), alkyd (partial discoloration), epoxy (unchanged); all fully visible, no occlusion, fixed viewpoint.

Manual:
Experimental Procedure
1. Place three identical bare metal specimens side-by-side.
2. Coat left specimen with epoxy resin, middle with alkyd resin, right remains uncoated.
3. Insert all three into salt spray chamber; initiate continuous 5% NaCl mist spray at uniform pressure.
Observation of Experimental Phenomena
- Uncoated specimen develops reddish-brown rust patches during spray.
- Alkyd-coated specimen shows limited brown discoloration at edges or flaws.
- Epoxy-coated specimen remains visually unchanged — no discoloration or blistering.
Summary of Experimental Principles
Epoxy resin provides superior barrier protection against chloride ion penetration; alkyd offers moderate protection; uncoated metal undergoes direct electrochemical corrosion in saline environment.

Prompt Grounding rubric:
level_1: No metal specimens are shown at all, or none of the three coating states (epoxy, alkyd, uncoated) can be told apart, or there's no salt-spray chamber or mist, or the specimens aren't arranged side by side for comparison.
level_2: At least one specimen appears, but there are fewer than three, or only one coating type can be identified while the other two are unclear; the spray chamber or the mist itself is missing or looks like something else (e.g., plain water dripping); the specimens are not placed together in the same shot.
level_3: Three metal specimens sit side by side in the same shot; one has a glossy, uniform painted surface consistent with an epoxy coating, one has a duller, semi-gloss or matte painted surface consistent with an alkyd coating, and one shows bare, shiny metal with no coating; a salt-spray chamber (or its enclosure) is visible in the background, and a continuous mist is directed at all three specimens at the same time.
level_4: Everything in score 3 holds, and the mist looks the same reaching each of the three specimens (same direction, similar density, nothing blocking any one of them), and each specimen keeps its own distinct look (glossy, semi-gloss/matte, or bare metal) without the three surfaces blending together at any point in the clip.
level_5: Everything in score 4 holds, and the mist starts hitting all three specimens at the same moment rather than starting on one first, nothing is added to or removed from the scene between frames, and all three specimens stay fully visible and in the same spot in a fixed camera view from start to end.

Scientific and Causal Correctness rubric:
level_1: None of the three specimens shows any sign of rust or discoloration during the spray, or all three look identical the whole time, so there's no way to tell the coatings apart by how they hold up.
level_2: One specimen does show a color change, but it's on the wrong one (say, the epoxy-coated piece shows rust), or all three rust the same amount, or the bare uncoated piece stays clean while a coated one doesn't.
level_3: The bare uncoated specimen develops reddish-brown rust patches during the spray; the epoxy-coated specimen shows no discoloration or surface change at all; the alkyd-coated specimen shows some partial discoloration (small brown spots, mainly at edges or scratches), and all of this only appears during the spray, in the areas where corrosion would actually be expected to start.
level_4: Everything in score 3 holds, and the amount of visible corrosion follows the expected order (uncoated shows the most rust, alkyd shows small isolated spots, and epoxy shows none), with the epoxy specimen staying completely clean no matter how long the spray runs.
level_5: Everything in score 4 holds, and the rust on the uncoated specimen reads as reddish-brown (not black, blue, or green); the alkyd specimen's discoloration only shows up at obvious surface flaws like scratches or edges rather than spreading evenly; and no discoloration shows up before the mist starts or keeps changing after the spray ends and the clip freezes on its final frame.

Spatiotemporal Consistency rubric:
level_1: A specimen jumps to a different size, position, or angle between frames; the mist appears or vanishes with no motion leading up to it; the lighting suddenly swings from bright to dark mid-clip; a specimen's surface flickers or visibly warps.
level_2: At least two clear problems show up together: for example, one specimen is missing for a stretch of the clip and then is back in a later frame, or the mist starts over one specimen and then jumps to another without any visible path between them, or the shadows point in a different direction than earlier in the clip, or the chamber wall or a specimen's shape briefly breaks apart.
level_3: None of the three specimens is ever missing from the scene; all three stay in the same positions relative to each other; the mist travels toward the specimens along a continuous, visible path; the direction of the light and shadows stays the same from the start of the clip to the end; no specimen or part of the chamber looks stretched, warped, or distorted.
level_4: Everything in score 3 holds, and the mist's density and direction stay steady across the whole clip with no sudden pulses or reversals, and the clip plays smoothly with no visible skipping or dropped moments that break the sense of continuous time passing.
level_5: Everything in score 4 holds, and the camera never pans, tilts, or zooms; the three specimens keep the same spacing and alignment relative to each other and the background, confirming a genuinely fixed viewpoint; the overall brightness and color of the scene stay steady with no flickering; and the edges of each specimen stay clearly defined throughout, never blurring in a way that would hide their surface condition.