Domain: Engineering — Geotechnical Engineering
Target concept: Strength Comparison Test of Lime-Modified Clay

Video generation prompt: Drop two soil samples from the same height onto the ground, where sample A is pure clay and sample B is a mixture of lime and clay. Subsequently, observe and compare the damage experienced by sample A and sample B.

Evaluation guide:
(i) Target concept: Lime stabilization enhances the mechanical integrity of clayey soils under dynamic loading.
Minimum mechanism: Pure clay has high water affinity and low tensile strength → brittle failure on impact; lime addition triggers pozzolanic reactions and cation exchange → reduced plasticity, increased inter-particle bonding → enhanced ductility and impact resistance.
(ii)Storyline: [Frame 0–2] Static wide shot: two adjacent soil samples on platform, labeled or visually distinct (A brown, B pale gray), ground visible below. [Frame 3–5] Simultaneous release: both samples begin downward motion in parallel vertical paths. [Frame 6–8] Impact event: both contact ground in same frame; A visibly fragments/scatters; B remains whole and undistorted. [Frame 9–10] Static post-impact: side-by-side comparison clear, no motion, no recovery — damage difference fully exposed. Perspective: fixed frontal orthographic-like view; full samples and ground always fully visible; no occlusion.

Manual:
Experimental Procedure
1. Place two identically sized soil samples side-by-side on an elevated platform: Sample A (pure clay, brown/dull), Sample B (lime-modified clay, pale gray/whitish). 
2. Release both samples simultaneously from same height onto a firm, level ground surface. 
3. Observe immediate post-impact condition.
Observation of Experimental Phenomena
Sample A fractures, crumbles, or scatters into multiple pieces upon impact. Sample B remains intact, retains original shape, and shows no visible cracking or dispersion.
Summary of Experimental Principles
Lime modification reduces clay plasticity and increases cohesion and compressive strength, resulting in improved resistance to mechanical shock and impact-induced failure.

Prompt Grounding rubric:
level_1: No soil samples visible; no drop action shown; no side-by-side arrangement; no ground surface present; no visual distinction between two samples.
level_2: Two soil samples appear but are not both present at the start of the video; drop action is absent or performed only on one sample; samples are not positioned adjacent in same frame; ground surface is missing or ambiguous.
level_3: Two soil samples (A and B) are visibly present and adjacent in the same scene before drop; both are released from identical height above ground in sequential or synchronous order; ground surface is clearly visible; no other objects dominate the frame.
level_4: All conditions for score 3 are met, AND both samples land on the ground within the same continuous shot; samples remain in fixed spatial relationship (side-by-side) throughout; no cut, zoom, or repositioning between release and impact.
level_5: All conditions for score 4 are met, AND both samples are released simultaneously (visually synchronized onset of motion), land in the same frame without motion blur obscuring shape/structure, and retain distinct identity (A vs. B labeling or consistent color/texture differentiation) from setup through post-impact observation.

Scientific and Causal Correctness rubric:
level_1: No causal link between drop and damage; both samples show identical post-impact state (e.g., both fully intact or both fully disintegrated); no observable difference in structural integrity after impact.
level_2: One sample shows damage but the other does not, yet their material identities are indistinguishable (no visual cue differentiating pure clay vs. lime-modified clay); or damage appears reversed (A less damaged than B).
level_3: Two visually distinguishable samples (e.g., differing color, texture, or surface finish) land on ground; sample A (pure clay) shows visible fragmentation, cracking, or dispersal; sample B (lime-modified clay) remains largely cohesive with minimal or no visible breakage; difference is present and unambiguous.
level_4: All conditions for score 3 are met, AND the damage contrast is sustained across the full post-impact observation window (no recovery, reassembly, or masking); no extraneous phenomena contradict geotechnical behavior (e.g., bouncing, melting, flowing).
level_5: All conditions for score 4 are met, AND sample A exhibits *only* brittle failure modes (cracks, shards, dust cloud upon impact) while sample B exhibits *only* ductile/cohesive retention (intact shape, no cracks, no particle separation), with no mixed or anomalous behavior inconsistent with lime stabilization improving tensile strength and reducing plasticity.

Spatiotemporal Consistency rubric:
level_1: Severe spatiotemporal violation: samples teleport between frames; ground surface shifts or disappears mid-drop; lighting changes abruptly; object edges flicker or dissolve; motion is discontinuous (e.g., jump-cut between pre-drop and post-impact).
level_2: Moderate violation: sample position shifts between frames without motion continuity; shadow direction or intensity changes inconsistently; one sample rotates or deforms unrealistically during fall; impact moment is missing or implied by cut.
level_3: All objects maintain consistent spatial relationships throughout; motion from release to impact is continuous and physically plausible (no floating, no acceleration reversal); lighting and shadows remain stable; no structural warping or interpenetration of objects.
level_4: All conditions for score 3 are met, AND camera viewpoint remains fixed (no pan, tilt, zoom, or dolly); both samples move along parallel vertical trajectories; ground surface shows no deformation prior to impact and no unrealistic rebound.
level_5: All conditions for score 4 are met, AND motion trajectory is smooth and noise-free across all frames; no motion blur that obscures sample identity or damage state; no temporal stutter, frame duplication, or dropped frames affecting causality perception.