Domain: Natural Science — Physics
Target concept: Parallel plate converts a wide light source into collimated light.

Video generation prompt: A bright wide-angle light shines toward a wall, and a metal plate with straight and parallel holes slides into the path of the light beam.

Evaluation guide:
(i) Target concept: Spatial filtering via parallel apertures produces collimated beamlets from diffuse illumination.
Minimum mechanism: Light must travel rectilinearly; holes must be physically opaque barriers with open channels; plate must be perpendicular (or near-perpendicular) to beam axis to preserve parallelism; wall must be distant enough for patches to resolve as discrete, non-diffracted spots.
(ii)Storyline: Frame 0–2: Wide-angle light illuminates wall uniformly. Frame 3–6: Metal plate enters field, sliding continuously from off-screen into beam path; as each hole crosses beam center, a corresponding light patch appears on wall in strict spatial correspondence. Frame 7–9: Plate fully inserted; all patches stably visible, aligned, separated, and identical in size/shape. Perspective: Fixed frontal view showing source–plate–wall alignment; wall fills lower third of frame; plate occupies central vertical band; light beam is clearly traceable from source through holes to patches; no obstructions or camera movement.

Manual:
Experimental Procedure
1. Illuminate a wall with a bright, wide-angle light source.
2. Slide a rigid metal plate — featuring straight, evenly spaced, parallel holes — directly into the light beam path between source and wall.
Observation of Experimental Phenomena
Before plate insertion: broad, diffuse illumination covers large area of wall.
During plate insertion: discrete, sharp-edged, equally sized light patches appear on wall, aligned in straight line matching hole orientation; patches remain separate and non-overlapping.
Summary of Experimental Principles
Parallel plate with straight and parallel holes converts wide-angle incident light into multiple collimated beams — each hole acts as a spatial filter, transmitting only light rays traveling parallel to its axis.

Prompt Grounding rubric:
level_1: None of the three required elements appear: no bright, wide-angle light source, no wall, and no metal plate with holes; nothing in the frame suggests a light source aimed at a wall or a plate about to be inserted.
level_2: Only some of the required elements appear: the wall and light source may be visible but the metal plate never appears, or the plate appears but never moves into the beam, or the plate lacks visibly straight, parallel holes, or the light source is not actually aimed at the wall.
level_3: The wide-angle light source, the wall, and the metal plate with straight, parallel holes are all visible, and the plate slides into the space between the light and the wall; however, the sequence has a flaw: for example the plate begins sliding before the light is switched on, or the plate fully blocks the light with no patches of light passing through the holes at any point.
level_4: The light source, wall, and holed metal plate are all present and correctly arranged (light source aimed at the wall, plate positioned between them); the plate slides continuously and unambiguously into the beam path; the light stays visibly on before, during, and after the plate enters; only a minor cosmetic issue is present, such as brief partial occlusion of one hole's edge or slight jitter in the sliding motion.
level_5: The light source, wall, and metal plate are all present, clearly shaped, and correctly arranged: the light source visibly emits a broad forward beam, the wall is flat and receives the light, and the plate carries clearly visible, evenly spaced, straight parallel holes; the plate slides smoothly all the way into the beam path between source and wall while the light remains continuously visible throughout; no object duplicates, disappears, or changes shape at any point.

Scientific and Causal Correctness rubric:
level_1: The wall looks the same before and after the plate slides in: no new pattern of light appears, or the beam appears to bend sideways or vanish instead of forming patches; there is no visible change in the light on the wall that could be attributed to the plate.
level_2: Light on the wall changes after the plate enters, but not in the way collimation would produce: the beam narrows into a single scattered blob rather than separate patches, or the patches produced overlap, curve, or diverge instead of forming straight parallel beams, or the plate blocks all light with nothing passing through the holes.
level_3: After the plate enters the beam, separate patches of light appear on the wall whose count and rough alignment match the holes in the plate, showing that each hole lets through its own beam; however, the patches are noticeably uneven in spacing or brightness, or they only appear once the plate has stopped moving rather than progressively as it slides in.
level_4: As the plate slides into the beam, separate light patches appear on the wall progressively, one per hole, matching the holes in count and straight-line alignment; the patches stay distinct, evenly spaced, and non-overlapping for as long as the plate remains in the beam, correctly showing each hole acting as its own narrow beam; at most one patch is slightly dimmer than the rest while still clearly present and correctly placed.
level_5: Before the plate enters, the wall shows one broad, diffuse patch of light; as the plate slides in, sharp-edged, evenly sized light patches appear one by one on the wall in the same straight-line arrangement as the holes, staying separated and evenly bright with no blur or halo around their edges; if the plate withdraws, the wall visibly returns to the original diffuse illumination, showing the collimation effect is directly tied to the plate's position.

Spatiotemporal Consistency rubric:
level_1: The scene breaks continuity outright: the plate jumps from off-screen directly to the center of the beam without a visible slide, the wall or light source blinks out and back, the beam appears disconnected from the light source at some point, or the overall room lighting suddenly changes for no reason tied to the plate's motion.
level_2: The plate slides in, but with visible instability: it rotates or bends as it moves, the wall's surface appears to warp or change texture, the beam appears to break into disconnected segments, or the plate's motion stutters with two or more visible freezes or jumps.
level_3: The wall stays flat and stationary, the light source stays in place, and the plate keeps a rigid shape and steady orientation as it slides in one continuous direction; the light patches on the wall stay consistent with the plate's position; one minor artifact is acceptable, such as the plate briefly looking semi-transparent for an instant or one frame where the patch count looks slightly off due to motion blur.
level_4: The plate's edges and the wall stay consistently aligned frame to frame with no visible misalignment; the pattern of light patches does not strobe or double-image; there are no sudden brightness spikes in the beam or on the wall; the entire sliding motion and the patches' appearance progress smoothly in one consistent direction without reversing.
level_5: The plate keeps a visibly constant, rigid shape throughout its slide: no bending, twisting, resizing, or fading in and out; the wall shows no warping or stretching; the beam stays visibly anchored to the light source in every frame; every light patch that appears keeps a crisp, steady edge for as long as it is visible; the sliding motion and patch formation look fluid from start to finish, with no stutter, freeze, or ghosting.