This monkey sprite head-tracking page documents a personal pipeline on aogl.cn: turn a short head-turn video into a sprite sheet, calibrate angle-to-frame mapping (not a naive angle/360*frames linear map), and ship a mouse-driven HTML demo with a custom peach cursor. Keywords that match real searches include sprite sheet head turn, CSS background-position animation, interactive character follow mouse, chroma key to WebP.
Pipeline in one sentence
Extract frames, build a contact / calibration sheet to read true facing directions, map compass angles to frame numbers, pack a 10x12 grid (120 frames) into sprite_hd_120.webp, and validate up / right / down / left / diagonals / center in the browser.
calibration_sheet.jpg: contact sheet used to build the angle-to-frame lookup.Front reference frame
The neutral camera-facing still is exported as frame_front.webp for thumbnails and as a sanity check before packing the grid.
frame_front.webp: front pose reference.Live demo: 120-frame HD + peach cursor
Move the mouse around the character: the viewer steps through 120 background positions on sprite_hd_120.webp (10 columns x 12 rows). A peach image follows the pointer with pointer-events: none so clicks still reach the page.
original/monkey2/gemini-code-1778834915677.html uses sprite_hd_120.webp and cursor.png.Sprite sheet assets
Three WebP masters document the iteration: standard density, HD, and the final 120-frame grid used in production.
Source stills (turn_head_1-10)
Ten numbered PNGs sample the rotation arc before packing the full grid, useful for QA and for alt-text-rich galleries.
Source video (MP4)
Two exports document early and refined head-turn passes; chroma was keyed to transparency before sprite packing.
turn_head_v1.mp4turn_head_v2.mp4Generative style anchors
Two Gemini exports in original/monkey2/ sit beside the technical assets for social previews and image search, not replacements for the calibrated sprite.
Offline tooling
Python helpers (gemini-code-1778834954429.py, gemini-code-1778835935559.py, gemini-code-1778835961926.py) and notes in txt.txt record the extraction and chroma rules (preserve subject, avoid eating white/grey). This article keeps the public-facing HTML, images, and video paths stable for SEO.