Domain: Engineering — Materials Science & Engineering
Target concept: Visual Comparison of Acoustic Properties of Construction Materials

Video generation prompt: Using acoustic wave ripples (waveforms) to represent sound propagation, show sound waves traveling outward from a source toward a sponge block and a glass pane placed side by side, and continuing past each material to the far side.

Evaluation guide:
(i) Target concept: Differential behavior of a propagating sound waveform when it passes a porous sponge versus a rigid glass pane, driven by how much each material damps (dissipates) acoustic energy.
Minimum mechanism: Sound must be shown as a propagating spatiotemporal waveform; the sponge's porous structure must convert acoustic energy into heat through internal friction, rapidly shrinking and stopping the waveform on its far side; the glass's rigid, non-porous structure must damp the wave far less, letting the waveform continue past it with only gradual amplitude loss over a much longer distance; both materials must be reached by the wave at the same moment from the same source.
(ii)Storyline: [Frame 0-2] The acoustic source (e.g., a speaker cone) activates, visibly starting to vibrate; [Frame 3-5] a waveform ripple emerges from the source and travels outward toward the sponge block and the glass pane, placed side by side at equal distance from the source; [Frame 6-8] the waveform front reaches both materials at the same instant; [Frame 9-10] past the glass, the ripple continues on largely intact; past the sponge, the ripple visibly shrinks and stops within a short distance — all shown from a fixed frontal viewpoint with both materials fully visible and unoccluded throughout.

Manual:
Experimental Procedure
1. Place a sponge block and a glass pane side by side, at equal distance from an active acoustic source (e.g., a speaker diaphragm).
2. Activate the source to emit a steady tone.
3. Visualize the sound as a real-time acoustic wave ripple emanating from the source and reaching both materials at the same moment.
Observation of Experimental Phenomena
- Past the glass: the wave ripples continue on, evenly spaced and extending well beyond the pane, losing only a small amount of amplitude.
- Past the sponge: the wave ripples lose amplitude and their even spacing rapidly, and stop within a short distance of the sponge's surface.
Summary of Experimental Principles
The sponge's porous, fibrous structure dissipates acoustic energy into heat through internal friction as the sound wave moves through its open cells, causing rapid attenuation. The glass's rigid, non-porous structure has much lower internal damping, so sound passing it loses comparatively little energy, letting the waveform persist much farther on the far side.

Prompt Grounding rubric:
level_1: No acoustic source is visible; or the sponge block is absent; or the glass pane is absent; or no waveform/ripple visualization appears at all; or the objects shown are the wrong materials (e.g., a wood block instead of the sponge, a metal sheet instead of the glass pane).
level_2: An acoustic source and at least one of the two materials are present, but the other material is missing from the scene entirely; or both materials appear but only in separate, disconnected shots rather than together in one continuous frame; or a waveform appears but does not visibly originate from the acoustic source (e.g., ripples seem to start from a material instead).
level_3: The acoustic source, the sponge block, and the glass pane are all present together in a single continuous shot; the source is shown activating (visible vibration or a clear onset cue) before any waveform appears; the sponge and glass sit side by side at roughly the same distance from the source; a waveform emerges from the source and travels toward both materials along the correct outward direction.
level_4: Everything described above still holds, and in addition: the sponge and glass sit at equal distance from the source so the wavefront reaches both at the same time; the sponge reads as visibly soft, porous, and matte, while the glass reads as smooth, rigid, and transparent, with no ambiguity about which is which; the camera viewpoint stays fixed with both materials fully visible and unoccluded from source activation to the end of the clip; no extraneous props or duplicate sources appear.
level_5: Everything described above still holds, and in addition: the source, sponge block, and glass pane keep consistent size, shape, and relative position to one another for the entire clip; the waveform's point of origin stays aligned with the source's physical location throughout; no part of either material or the source is cropped out of frame or blocked by hands, labels, or other objects at any point.

Scientific and Causal Correctness rubric:
level_1: The waveform behaves identically behind both materials, with no visible difference in how far it travels or how strong it stays; or the waveform noticeably weakens past the glass while staying strong past the sponge (the reversed, incorrect pattern); or the waveform appears to originate from the sponge or glass themselves rather than from the source.
level_2: The waveform is visible past only one of the two materials; or the waveform past the glass shows clear damping or shortening (the wrong direction of the effect); or the waveform looks exactly the same past both materials despite their different textures being visible; or the sponge is shown behaving as rigid (no compression or give) while the scene still treats it as the absorbing material.
level_3: The waveform is visible past both materials; past the glass, the ripples keep repeating and extend a visibly longer distance than past the sponge; past the sponge, the ripples are visibly weaker and shorter in extent than past the glass; the waveform only appears after the source visibly activates, never before.
level_4: Everything described above still holds, and in addition: past the sponge, the ripples become visibly irregular, unevenly spaced, or broken up rather than staying evenly spaced, while past the glass the ripples keep a steady, evenly spaced repeating pattern; at no point does the glass side show more disruption or scattering than the sponge side.
level_5: Everything described above still holds, and in addition: past the sponge, the ripples stop within a short, clearly bounded distance of the sponge's surface with no faint trailing ripples beyond that point; past the glass, the ripples keep going with visibly consistent spacing and strength all the way to the edge of the frame; the sponge reads as soft/porous/matte and the glass as smooth/rigid/transparent throughout; the differential pattern (strong and long past glass, weak and short past sponge) only develops after the source visibly activates and the wave appears, never before.

Spatiotemporal Consistency rubric:
level_1: The sponge block or the glass pane vanishes from the frame and reappears elsewhere with no camera or object motion explaining it; the waveform ripple jumps from one position or size to a completely different one between adjacent frames with no continuous propagation shown; the source, sponge, or glass changes shape or warps at any point in the clip; or the lighting across the whole scene suddenly switches to a different setup with no cause shown.
level_2: Both materials stay visible, but one intermittently blocks the other in a way that changes from frame to frame with nothing moving to cause it; the ripple pattern appears, disappears, then reappears with no visible interruption shown; or the sponge or glass slides or rotates in place partway through the clip with no hand, wind, or other visible cause.
level_3: The sponge block, glass pane, and acoustic source each stay in the same position, size, and orientation for the whole clip; the ripple emerges from the source and travels outward as one continuous, unbroken motion with no stutters or skipped frames; neither material changes shape or breaks apart at any point; the camera viewpoint does not move.
level_4: Everything above holds, and in addition: nothing ever blocks the view of the sponge or glass surfaces during the ripple's approach and passage; the ripple's shape never suddenly stretches, shrinks, or snaps into a different pattern between frames; the light falling on the sponge and glass keeps the same direction and strength from the first frame to the last, without any sudden brightening, dimming, or flare appearing.
level_5: Everything above holds, and in addition: the ripple's path stays aligned with the source's fixed location and the straight line toward each material, without drifting to one side; the sponge and glass keep the same relative depth and overlap relationship with the ripple throughout, never rendering as if one jumped in front of or behind the wave incorrectly; the sponge side and glass side develop their different ripple behavior in sync, with neither one visibly lagging behind or leading the other.