Domain: Humanities and Social Sciences — Arts
Target concept: Sketch - Three-Point Perspective

Video generation prompt: Display a smooth drawing plane, where the artist employs the technique of three-point perspective to draw a high-rise building.

Evaluation guide:
(i) Target concept: Three-point perspective as a geometric projection system for representing volumetric height and depth on a planar surface.
Minimum mechanism: A rigid 3D scene containing mutually orthogonal edge families must project onto the image plane such that each family converges to a unique vanishing point, and the three vanishing points are not collinear.
(ii)Storyline: Frame 0–2: Blank smooth drawing plane appears, stable and uniform. Frame 3–6: Building outline begins at base and extends upward/outward; left-horizontal edges initiate convergence toward upper-left region, right-horizontal edges toward upper-right region, vertical edges toward upper-center or lower-center region. Frame 7–10: All lines extend continuously to their respective vanishing point regions; convergence becomes visually unambiguous; final frame shows complete building with three clearly separated, non-collinear vanishing points anchoring the perspective logic. Perspective must be maintained under fixed viewpoint: no camera movement, no rotation, no zoom.

Manual:
Experimental Procedure
1. Display a blank smooth drawing plane.
2. Draw a high-rise building using only straight lines.
3. Ensure all horizontal-left edges converge to one vanishing point, all horizontal-right edges to a second, and all vertical edges to a third — forming a triangular vanishing point layout.
Observation of Experimental Phenomena
Three distinct vanishing points appear in non-collinear positions; all building edges sort into exactly three convergence families; no parallel or diverging lines within a family; convergence is continuous and unbroken.
Summary of Experimental Principles
Three-point perspective uses three vanishing points to represent 3D space on a 2D plane: two on the horizon (left/right) for ground-plane receding lines, and one above or below (zenith/nadir) for vertical recession — enabling accurate depiction of tall structures viewed from extreme angles.

Prompt Grounding rubric:
level_1: No high-rise building sketch appears on the drawing plane; the drawing plane itself is not shown; no lines suggesting perspective construction of a building are present.
level_2: A building-like outline appears, but no smooth drawing plane is visible beneath it, and none of the lines show any converging orientation toward off-canvas regions; the sketch reads as a flat elevation with no perspective cues.
level_3: The high-rise building is drawn on a visible drawing plane, and lines from two edge families (e.g., left-horizontal and right-horizontal edges such as window rows or floor lines) visibly angle toward two separate off-canvas regions, but the vertical edges of the building either stay parallel (no convergence drawn) or are missing from the sketch entirely.
level_4: The building is drawn on the drawing plane with all three edge families present (left-horizontal, right-horizontal, and vertical), each angled toward its own off-canvas region; however, at least one of those regions is cut off by the frame edge, or one line segment breaks or misaligns partway through the drawing.
level_5: The high-rise building is fully drawn on the smooth drawing plane; lines from all three edge families (left-horizontal, right-horizontal, vertical) are present, unbroken, and each consistently angles toward its own distinct off-canvas region, with no region cropped by the frame, no gaps in any line, and no line that switches from one family's direction to another partway through.

Scientific and Causal Correctness rubric:
level_1: No causal link between line direction and vanishing-point convergence is visible; the drawn lines show no consistent directional logic; the building's edges contradict three-point perspective (e.g., the vertical edges stay parallel while the horizontal edges converge, or vice versa) with no visual justification for the mismatch.
level_2: Lines do converge, but their groupings violate orthogonality: for example, the left-horizontal and right-horizontal edge lines converge toward the same vanishing point instead of two separate ones, or the vertical edges converge both upward and downward at once.
level_3: Three vanishing points exist and are spatially separated, and each of the three edge families (left-horizontal, right-horizontal, vertical) converges toward its own vanishing point, but one family (e.g., the verticals) converges inconsistently, with some line segments converging correctly while others stay parallel or bend unnaturally partway through.
level_4: All three edge families converge correctly and continuously toward their respective vanishing points, but the three vanishing points themselves violate the geometry required for three-point perspective: for example, two of them sit on the same horizontal line while the third sits directly above or below the frame's center, so the three points do not form a proper triangular layout.
level_5: The three vanishing points sit at clearly different, non-collinear positions in the frame (they visibly form a triangle, not a line); each edge family (left-horizontal, right-horizontal, vertical) converges only toward its own assigned vanishing point, with no edge crossing into another family's convergence path; the convergence logic is visually self-consistent across the whole building.

Spatiotemporal Consistency rubric:
level_1: The drawing plane abruptly appears or disappears; the building outline breaks apart or teleports to a new position mid-sequence; the vanishing points jump to different locations between frames; visible flicker or structural discontinuity occurs in the sketch.
level_2: The drawing plane stays visible but visibly warps or ripples; the building's edges jitter or snap frame-to-frame instead of drawing smoothly; a vanishing point shifts by a large, clearly visible distance (more than the width of the drawing plane itself) between frames; the converging lines blink in and out intermittently rather than extending continuously.
level_3: The drawing plane stays flat and stable; the building outline is continuously present once drawn; the vanishing points stay in fixed positions once established; the converging lines are drawn without interruption, but there is a minor local glitch, such as a brief wobble in one line segment or an inconsistency in stroke thickness at one point.
level_4: The drawing plane stays stable and uniformly smooth; the building outline is continuous and intact; all converging lines stay unbroken with consistent stroke quality; the vanishing points stay fixed in place, but one line shows uneven tapering near its vanishing point (e.g., its width stays constant and then stops abruptly instead of gradually thinning).
level_5: The drawing plane stays rigid and flat with no warping; every line is drawn in continuous motion, its convergence advancing steadily with no jumps or reversals; the vanishing points show no visible drift or repositioning across the sequence; every line extends smoothly and unbroken from its starting edge to its vanishing region; line width thins naturally and continuously as each line approaches its vanishing point.