自习课教室里放大炮 · 老师只管让你收手机
15 秒荒诞写实短片，怎么做出来的？

PROMPT HEADER:
Create a 15-second horizontal 16:9 photorealistic live-action absurdist video in one uninterrupted first-person take at 30 fps. The viewer is a student quietly filming on a phone from a seated position near the back of an American high-school classroom with a practical private-school dress code. Keep a fixed, slightly wide-angle composition with only small natural handheld tremors. Rows of desks fill the left and center, all facing the distant chalkboard at the front, and an enormous wheeled cannon occupies the right foreground beside tall windows. No cuts, zooms, reverse angles, or time jumps. Everyone treats the absurd sight as routine.
CAMERA AND CLASSROOM LAYOUT:
Build a recognizable American classroom with painted cinder-block walls, fluorescent ceiling lights, a wall clock over a large green chalkboard, a side bulletin board with English class notices, a U.S. map, slightly worn tile flooring, metal-framed student desks, open textbooks, notebooks, pencils, and piles of classwork.
Tall white-framed windows run along the right wall, with pale floor-length curtains. Outside is an empty American campus athletic field and a low brick school building with distant trees. Keep the exterior sunlit and clearly visible through the windows.
Camera placement and seating direction are nonnegotiable: the lens is BEHIND the ordinary students and looks toward the front wall. Every ordinary desk has its writing edge and chair oriented toward the chalkboard, with students facing away from the camera. The lens mostly sees backs of heads, shoulders, and uniform jackets. A small side profile may appear when someone turns.
Never show a row of ties, chests, and full faces facing the lens while the teacher writes behind those students. Only the girl operating the cannon is seated sideways by the right window. The nearest student on the left bends over a workbook.
STUDENTS AND UNIFORM:
All people have distinct Western faces and stable identities. The older teenage students wear one coherent contemporary American private-school uniform: white or pale-blue polo or collared shirts, charcoal chinos, knee-length navy-and-gray plaid skirts, and optional navy sweaters or blazers with a modest school crest. A few students wear loosened navy ties; most do not. The clothing is practical and casually worn. The unseen operator filming the scene wears the same uniform.
Keep all ordinary students at their assigned desks. They write, turn pages, or make small natural movements while facing the chalkboard. No ordinary student enters the aisle before the cannon fires.
TEACHER CONTINUITY:
There is exactly ONE teacher. She is an adult Western woman with a short dark-brown bob, a plain white short-sleeved button-down blouse, and dark trousers. At the beginning she stands at the distant chalkboard with her back or side to the camera and writes with chalk.
She is the SAME woman who later leaves the board, walks down the aisle, speaks to the class, notices the phone, and confronts the student filming. Keep her appearance consistent and never add a second adult. She writes, pauses, scolds the class, then notices the phone.
CANNON GEOMETRY AND OPERATOR:
Lock the cannon geometry before any action begins. The huge dark-steel carriage, two thick black rubber tires with solid enclosed hubs, rear breech, and controls are INSIDE the classroom in the lower-right foreground.
A long pale-gray metal barrel runs diagonally UP AND TO THE RIGHT from that breech, crosses a visibly open section of the right-side window, and continues OUTSIDE toward the empty field. Its muzzle lies beyond the outer wall near the upper-right edge of the frame. Show one continuous, rigid barrel from interior breech to exterior muzzle in every frame, including during recoil.
This exact relationship is the most important spatial constraint: breech inside, barrel through the open right window, muzzle outside. Its line of fire points away from the classroom. It never angles left across the desks or toward the teacher, students, or camera. It never ends inside the room or passes through closed glass. It is a modern field gun with broad tires and enclosed hubs, never an antique spoked-wheel cannon. Never shorten or reverse the barrel.
A Western teenage girl with long dark hair sits on a low seat at the rear-left side of the cannon, between it and the nearest desks. She is shown in profile, with her hands near the rear controls, wearing the same school's white shirt, navy uniform layer, and plaid skirt. She stays seated in this position throughout. Before firing she makes small precise adjustments; afterward she remains composed. She never leaves her seat.
CONTINUOUS SHOT PLAN:
0.0-4.5 seconds — Quiet study hall:
Hold the established wide first-person view. At the front, the only teacher is still writing on the chalkboard, her chalk hand moving in short strokes. She may reach higher but does not turn, speak, or leave. Students, viewed from behind, lean over their books, write, and turn pages while facing the chalkboard. The girl beside the cannon adjusts its rear mechanism and settles her hands. The full barrel remains unmistakably aimed out of the right window. No one enters the aisle or approaches the lens before the shot.
4.6-4.9 seconds — One outward discharge:
The seated girl fires the cannon exactly ONCE, outward toward the unoccupied field. Her small control movement leads to one abrupt report. Show a split-second warm flash at or just beyond the EXTERIOR muzzle, a brief recoil and vibration through the fixed carriage, then a restrained puff of pale smoke at the open window.
The nearby long curtain snaps upward and inward, twists in the moving air, and begins to settle. Normal daylight returns immediately. Both solid-hub rubber wheels stay planted and the long barrel retains its rightward outdoor direction. Show no indoor fire, shown impact, or second discharge.
5.0-8.8 seconds — Deadpan aftermath:
Show the aftermath of that single shot. The curtain continues to sway and gradually falls back. Thin haze drifts along the right windows and starts to disperse. Its continuing motion must not read as another cannon shot.
A few students briefly lift their heads or shift in their seats, while most keep working and quickly resume writing. The girl at the controls stays calmly seated. At the far front, the teacher stops writing, lowers her chalk hand, and turns from the board after hearing the report. She remains near the front during this immediate aftermath and is annoyed by the noise. The room stays fixed.
8.8-10.5 seconds — Teacher's first reprimand:
The SAME teacher faces the room and says in natural American English, firmly and matter-of-factly: “This is study hall. Keep it quiet.” She glances over the desks, then steps away from the chalkboard into the center aisle.
Start her walk visibly at the front. She must gradually grow larger as she passes successive desk rows. Show a continuous normal-paced walk from the front. The operator remains seated and the barrel remains outside.
10.5-13.9 seconds — She notices the phone:
The teacher walks farther down the same aisle, with desks on her left and the cannon operator near her right as she approaches the phone viewpoint. Her gaze first scans the room and then fixes directly on the lens when she notices the unseen student recording.
Her brows tighten slightly. Her face changes from general irritation about the noise to direct disapproval of the phone. Address only the person behind the camera, not the girl at the cannon. Say once, clearly and with natural lip synchronization: “And you—why is your phone out? Put it away.” The unseen student does not reply; the phone itself need not appear. Keep her walk continuous from the chalkboard into the foreground.
13.9-15.0 seconds — Hand covers the lens:
Now close enough for her face and upper body to be clearly recognized, the teacher leans toward the lens, raises one hand from her side in a visible motion, and extends her open palm toward the student's phone. Her face remains briefly visible behind the growing hand. The hand fills the frame naturally as it reaches the lens, and the image darkens because the palm physically covers it.
Finish there. This is the only full lens obstruction in the video: no early hand, no disembodied hand, and no hidden cut behind it. The camera may shift a fraction in the student's grip at the final touch but never changes viewpoint.
PERFORMANCE, AUDIO, AND TONE:
Keep the pacing fluid rather than freezing each time interval into a separate shot. The teacher's chalk writing leads into her pause, turn, spoken warning, uninterrupted walk, phone reprimand, and final reach. The girl's adjustment leads into one outward cannon discharge, then one continuous curtain-and-haze aftermath.
Use modest classroom ambience, chalk and pencil sounds, one short heavy report, moving fabric, footsteps, and only the teacher's two short English lines. Keep both lines intelligible. No other dialogue, music, captions, titles, or logos.
The final tone is deadpan: the teacher objects to noise and a phone while the enormous cannon remains beside students who are quietly doing their work. Preserve all character identities, uniforms, props, and spatial relationships from the first frame to the last.
VISUAL AND CONTINUITY RULES:
Photorealistic live-action classroom comedy with natural daylight from the right, practical fluorescent light, restrained handheld motion, realistic smoke and fabric movement, stable faces, stable uniforms, and physically coherent props. Keep the classroom architecture fixed. Keep the cannon barrel rigid and continuous from breech to exterior muzzle. Keep the window section open where the barrel passes through. Keep the cannon operator seated and the teacher's walk physically continuous.
Do not turn the scene into an action film, war scene, horror scene, or video game. The absurdity comes from the students and teacher treating the cannon as ordinary while reacting only to noise and phone use.
NEGATIVE PROMPT:
Second teacher, extra adults, duplicate teacher, teacher identity drift, teacher teleportation, teacher starting near the camera, teacher appearing without walking, teacher addressing the cannon operator, teacher facing the wrong direction, students facing the camera at ordinary desks, rows of full faces toward the lens, desks facing away from the chalkboard, reversed classroom layout, cannon aimed left, cannon aimed at people, cannon aimed at camera, barrel ending inside classroom, shortened barrel, reversed barrel, broken barrel, barrel through closed glass, missing open window, floating cannon, antique spoked wheels, missing tires, detached carriage, changing cannon geometry, cannon recoil changing its direction, second firing, repeated muzzle flash, indoor muzzle flash, shown impact, fire inside classroom, explosion, dangerous debris, cannon operator standing, operator changing seats, operator leaving frame, students abandoning desks, extra cannon, duplicate students, cloned faces, unstable identities, changed uniforms, missing chalkboard, missing windows, missing curtains, dark exterior, unreadable classroom signs, readable brand names, captions, subtitles, titles, logos, watermark, music, extra dialogue, missing dialogue, bad lip synchronization, early hand obstruction, disembodied hand, hidden cut behind hand, zoom, reverse angle, time jump, camera viewpoint change, excessive camera shake, excessive smoke, excessive motion blur, horror lighting, war-movie tone, videogame render, low resolution, blurry faces, distorted hands, extra fingers, extra limbs, broken anatomy, unnatural curtain motion, sound mismatch.
Final Summary
Create one complete 15-second horizontal 16:9 photorealistic live-action absurdist classroom video at 30 fps. Use Reference Video only for fixed first-person framing, subtle handheld movement, natural pacing, and deadpan comedy timing. The written prompt controls the classroom, one consistent teacher, uniformed students viewed from behind, the seated cannon operator, the cannon's interior-to-exterior geometry, one outward shot, the teacher's two lines, her continuous walk, and the final palm covering the lens.
The finished video should make the joke legible without changing the room's ordinary routine: a cannon fires outside the classroom, but the teacher's priorities are keeping study hall quiet and stopping the student from filming. Preserve the spatial logic, physical continuity, two short English lines, one heavy report, restrained aftermath, and final lens obstruction.