Domain: Engineering — Energy Engineering
Target concept: Heat diffusing radially from a point on a uniform metal plate

Video generation prompt: A uniform aluminum plate coated with opaque wax is heated by a small heater contacting its exact center.

Evaluation guide:
(i) Target concept: Radial conductive heat diffusion in a uniform isotropic solid (aluminum) driving localized opacity reduction in an overlying phase-change material (wax). Minimum mechanism: Aluminum must be thermally conductive and homogeneous; wax must be opaque in solid state and become translucent (not transparent or colored) upon partial melting; heater must be a localized, steady-state thermal source at the center; no convective or radiative dominance allowed.
(ii)Storyline: Frame 0–1: Static shot: fully opaque, uniform white wax coating on flat aluminum plate; small heater visibly touching exact center. Frame 2–4: First translucent ring appears concentric with heater; outer wax remains fully opaque. Frame 5–7: Translucent region expands continuously, preserving circular shape and sharp leading edge; no asymmetry or branching. Frame 8–10: Expansion persists with same morphology; no re-opacity, bubbling, or edge instability. Perspective: Fixed frontal orthographic-like view (no parallax); full plate visible; center clearly identifiable by symmetry; no occlusion of heater–plate interface or expansion front.

Manual:
Experimental Procedure
1. Place a uniform rectangular aluminum plate flat on a stable surface.
2. Coat entire upper surface evenly with opaque white wax (solid at room temperature).
3. Position a small electric heater in direct, stationary contact with the exact geometric center of the wax-coated surface.
4. Activate heater and observe for 10 seconds.
Observation of Experimental Phenomena
A circular region of wax centered on the heater becomes progressively translucent, expanding radially outward while maintaining circular symmetry; wax outside this region remains fully opaque and unchanged.
Summary of Experimental Principles
Heat diffuses radially from the point source through the uniform metal plate; conduction transfers energy to the overlying wax, reducing its opacity via localized phase transition (solid → translucent semi-molten state) without full liquefaction.

Prompt Grounding rubric:
level_1: No aluminum plate is visible, no wax coating is visible, and no heater is shown touching the plate: none of the three required elements (aluminum plate, opaque wax coating, center-contact heater) appear in the frame.
level_2: The aluminum plate is visible, but either the wax coating is missing or is already visibly liquid or transparent at the start, or the heater is not actually touching the plate, or the heater touches the plate somewhere clearly off-center rather than at the middle.
level_3: A flat aluminum plate fully coated in opaque white wax is visible, and a small heater is shown in direct contact with the middle of the wax-coated surface; the heater looks active (for example, it glows steadily or has a visibly lit indicator); no unrelated objects or hands are in frame.
level_4: The plate, the uniform opaque wax coating, and the centered, active heater are all present as in the 3-point level, and in addition the heater stays in continuous contact with the same spot for the whole video, the wax looks uniformly opaque and solid at the very start, and the plate's edges stay fully visible with no cropping or occlusion.
level_5: Everything from the 4-point level holds, and in addition the heater is the only visible heat source, the plate shows no pre-existing cracks or discoloration, the wax looks even in color and texture across the whole surface at the start, and the heater's contact point looks centered on the plate by eye (for example, roughly equal wax margins visible on all sides).

Scientific and Causal Correctness rubric:
level_1: The wax stays fully opaque and unchanged everywhere for the whole video: no translucent patch appears near the heater at all, so no radial pattern of any kind shows up.
level_2: A translucent patch does appear, but not centered on the heater or not expanding outward in a roughly circular way: for example the translucent area only forms an irregular blob matching the heater's outline without growing, or the wax appears to skip straight to fully clear liquid instead of passing through a translucent stage, or the wax darkens or discolors instead of losing opacity.
level_3: A roughly circular translucent patch appears centered on the heater and visibly grows outward over time; the wax outside this patch stays fully opaque; there is no bubbling, browning, or other color change beyond the loss of opacity.
level_4: Everything from the 3-point level holds, and in addition the translucent patch grows steadily outward without pausing, shrinking back, or restarting; the patch keeps a roughly circular shape as it grows; no separate translucent spots appear away from the center; no opaque patches remain trapped inside the translucent area once the front has passed them.
level_5: Everything from the 4-point level holds, and in addition the edge of the translucent patch stays sharp and even all the way around rather than fading gradually into the opaque wax; no part of the translucent area re-solidifies back to opaque during the expansion; the degree of translucency looks even across the whole growing patch rather than patchy or streaky.

Spatiotemporal Consistency rubric:
level_1: The plate or heater vanishes and reappears, or the wax coating's opacity jumps back and forth rather than changing in one direction, or the room lighting or shadows swing abruptly for no reason tied to the heating, or the plate visibly rotates or warps during the video, or the video stutters or drops frames badly enough to break the sense of continuous motion.
level_2: The plate stays visible throughout but shows repeated small position shifts or wobble; the heater's contact point visibly drifts away from the center as the video plays; the wax's opacity appears to change in a few visible jumps rather than a gradual fade; the lighting brightens on one side of the frame while dimming on the other for no clear reason.
level_3: The plate stays in the same position, scale, and orientation for the whole video; the heater stays in constant contact with the same central spot; the wax's opacity changes gradually rather than in visible jumps; the overall lighting on the plate looks steady rather than swinging brighter or dimmer; there is no visible tearing or morphing of the plate or wax.
level_4: Everything from the 3-point level holds, and in addition the plate's edges and the heater's outline stay steady from frame to frame with no visible misalignment; the growing translucent front does not strobe, double, or flicker; there are no sudden brightness spikes anywhere on the plate; the whole expansion proceeds at a steady, unhurried pace consistent with heat spreading outward, without speeding up, freezing, or reversing.
level_5: Everything from the 4-point level holds, and in addition the plate shows no visible warping or stretching of its edges over the video; the heater's position relative to the plate looks fixed with no drift; the opaque areas of the plate look evenly and steadily lit throughout with no visible flicker; the translucent front's growth looks smooth and continuous at a pace that reads as natural heat diffusion, without unnatural blurring or freezing of its edge.