Domain: Humanities and Social Sciences — Arts
Target concept: Drawing - Atmospheric Perspective

Video generation prompt: Display a canvas on which the painter applies aerial perspective to sequentially depict the foreground, middle ground, and background of a landscape.

Evaluation guide:
(i) Target concept: Atmospheric perspective as a depth-cueing technique in painting.
Minimum mechanism: Light scattering in atmosphere must be modeled implicitly through progressive reduction of visual acuity (edge definition) and chromatic intensity (contrast/saturation) across increasing distance zones, without requiring explicit physics simulation.
(ii)Storyline: Frame 1–2: Painter approaches blank canvas; brush lifted, ready. Frame 3–5: Brush contacts canvas and begins rendering foreground elements with high-definition, vivid strokes. Frame 6–7: Painter extends stroke upward/backward to add middle ground; strokes visibly soften, colors desaturate. Frame 8–10: Painter completes background with broad, hazy, low-contrast strokes; all three layers coexist simultaneously in fixed viewpoint; foreground remains crisply legible while background fades into atmospheric ambiguity; no occlusion or layer reordering occurs.

Manual:
Experimental Procedure
1. A painter stands before a blank canvas.
2. Using a brush, the painter applies pigment to depict a landscape scene.
3. The painted scene explicitly separates into three spatial zones: foreground (closest), middle ground (mid-distance), and background (farthest).
Observation of Experimental Phenomena
- Foreground elements appear with highest contrast, sharpest edges, and most saturated colors.
- Middle ground elements appear with reduced contrast, softer edges, and muted colors.
- Background elements appear with lowest contrast, most blurred/indistinct edges, and palest/least saturated colors.
Summary of Experimental Principles
Atmospheric perspective is an artistic technique where distant objects are rendered with decreasing contrast, edge sharpness, and color saturation to simulate the effect of atmospheric particles scattering light over distance—creating an illusion of depth on a 2D surface.

Prompt Grounding rubric:
level_1: No landscape canvas visible; no painter figure present; no discernible foreground/middle ground/background spatial layers; no brush application action shown.
level_2: A static landscape image is present but lacks any human agent or tool; or a painter appears but does not interact with a canvas; or only one spatial layer (e.g., only background) is depicted without differentiation.
level_3: A painter is shown applying pigment to a canvas, and the resulting image contains at least two spatial layers (e.g., foreground + background) that are visually distinct in position and scale, but the middle ground is missing or indistinguishable from foreground or background.
level_4: A painter applies pigment to a canvas, and the resulting image displays three spatial layers (foreground, middle ground, and background), each visibly present and positioned in correct relative order (near-to-far), but at least one layer fails to exhibit the required atmospheric perspective cues (e.g., all layers share identical color saturation and edge sharpness).
level_5: A painter applies pigment to a canvas, and the resulting image displays three spatial layers (foreground, middle ground, and background) in correct near-to-far sequence, with each layer exhibiting the required atmospheric perspective cues: foreground shows highest contrast and sharpest edges, middle ground shows reduced contrast and softened edges, background shows lowest contrast and most blurred/indistinct edges, all within a single fixed-frame composition.

Scientific and Causal Correctness rubric:
level_1: No causal link between painter action and visual outcome; layers appear pre-rendered or unrelated to brushwork; no variation in color, edge definition, or contrast across distance zones.
level_2: Painter applies pigment, but all three spatial layers display identical visual properties (same color intensity, same edge clarity, same tonal value); no perceptible change in contrast, saturation, or sharpness correlated with spatial position.
level_3: Three spatial layers are present and ordered correctly, and at least one layer shows a difference in contrast or edge definition compared to another, but the gradient of change is inverted (e.g., background sharper than foreground) or inconsistent (e.g., middle ground matches foreground, not intermediate).
level_4: Three spatial layers are ordered correctly and show a monotonic decrease in contrast and edge sharpness from foreground → middle ground → background, but one cue is missing (e.g., saturation decreases but sharpness remains uniform, or vice versa).
level_5: Three spatial layers are ordered correctly and exhibit *both* decreasing contrast *and* decreasing edge sharpness from foreground → middle ground → background, with no reversal, gap, or inconsistency in the progression; foreground has highest contrast and sharpest edges, middle ground has intermediate contrast and softer edges, background has lowest contrast and most blurred/indistinct edges, all visually unambiguous and mutually reinforcing.

Spatiotemporal Consistency rubric:
level_1: The frame's viewpoint suddenly jumps between a frontal angle and a different angle (e.g., overhead), or the painter/easel/canvas shifts position within the frame with no corresponding brush or body motion to explain it, or the canvas surface visibly warps, tears, or its edge vanishes mid-sequence, or the lighting on the scene jumps abruptly in direction or intensity with no cause.
level_2: Viewpoint stays fixed, but the painter's hand or brush disappears from view and reappears at a different location mid-stroke without continuous motion connecting the two positions, the canvas's rectangular outline visibly warps out of its flat plane, the brush loses contact with the canvas mid-stroke and the next visible stroke begins at a disconnected point on the canvas with no travel shown between the two, or the light and shadow on the painter or canvas shift inconsistently across frames with no apparent cause.
level_3: Viewpoint is fixed, the painter keeps a consistent spatial relationship to the canvas, and the brush moves continuously, but both boundaries between the three depth zones (foreground/middle-ground and middle-ground/background) visibly shift position and then resettle at some point in the sequence, or a single boundary does this more than once.
level_4: Viewpoint is fixed, the painter keeps a consistent spatial relationship to the canvas, and the brush moves continuously; only one of the two zone boundaries shows a single, visible shift in position followed by resettling somewhere in the sequence, and no other boundary is affected and it does not recur.
level_5: No boundary shift, jump, or flicker occurs anywhere in the sequence: viewpoint remains fixed throughout, the painter's arm, hand, and brush move with continuous natural motion and every new stroke visibly begins where the brush last left the canvas with no disconnected jump in brush position, the canvas stays flat and planar, and both zone boundaries hold steady position and edge continuity in every frame shown.