[{"data":1,"prerenderedAt":16},["ShallowReactive",2],{"article-city-then-now-ai-time-travel-video-tutorial":3},{"errorCode":4,"errorMessage":5,"data":6},"00000","Everything ok",{"title":7,"category":8,"path":9,"description":10,"keyword":11,"content":12,"prevPath":13,"nextPath":14,"gmtCreate":15,"gmtModified":15},"Build an AI Time-Travel Video: Full “City Then & Now” Production Guide",4,"city-then-now-ai-time-travel-video-tutorial","From one core city-corner plate, use Seedream 5 Lite (text-to-image and image-to-image) for first and last frames, then Seedance v1 Lite image-to-video for a modern→retro transition; includes copy-ready JSON prompts, result analysis, and extension ideas.","City Then & Now, Seedream, Seedance, image to image, image to video, first frame, last frame, time travel, FuseAI Tools, AI video tutorial, 16:9","\u003C!DOCTYPE html>\n\u003Chtml lang=\"en\">\n\u003Chead>\n    \u003Cmeta charset=\"UTF-8\">\n    \u003Cmeta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n    \u003Ctitle>City Then & Now: AI Time-Travel Video — Full Tutorial\u003C/title>\n\u003C/head>\n\u003Cbody>\n    \u003Carticle class=\"ai-model-comparison\">\n        \u003Cheader>\n            \u003Ch1>Build an AI Time-Travel Video: Full “City Then & Now” Production Guide\u003C/h1>\n        \u003C/header>\n\n        \u003Csection class=\"introduction\">\n            \u003Cp>\u003Cstrong>Intro:\u003C/strong> Ever wanted a static street-corner photo to \u003Cem>come alive\u003C/em> and show decades of change? With AI image-to-image and image-to-video, you can. This article walks through the full \u003Cstrong>City Then & Now\u003C/strong> pipeline—core scene plate, first and last frames, then one smooth time-travel clip.\u003C/p>\n        \u003C/section>\n\n        \u003Csection class=\"why-core-scene\">\n            \u003Ch2>I. Why Reuse a “Core Scene”?\u003C/h2>\n            \u003Cp>First and last frames must match for believable motion. If layout, framing, and light differ wildly, the model struggles to bridge them.\u003C/p>\n            \u003Cp>\u003Cstrong>Our approach:\u003C/strong> generate one \u003Cstrong>environment-only plate\u003C/strong> (no people), then derive both keyframes from it. Same buildings, angle, and light—only “what changes” (people, era) is left for the model.\u003C/p>\n            \u003Cp>\u003Cstrong>Comparison:\u003C/strong>\u003C/p>\n            \u003Ctable style=\"width:100%; border-collapse:collapse; margin:1rem 0;\">\n                \u003Cthead>\n                    \u003Ctr style=\"border-bottom:1px solid #e5e7eb;\">\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Method\u003C/th>\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Scene match\u003C/th>\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Transition\u003C/th>\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Best for\u003C/th>\n                    \u003C/tr>\n                \u003C/thead>\n                \u003Ctbody>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Two unrelated generations\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Uncontrolled\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Okay\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Quick tests\u003C/td>\u003C/tr>\n                    \u003Ctr>\u003Ctd style=\"padding:0.5rem;\">\u003Cstrong>Shared core plate\u003C/strong>\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Fully controlled\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Smooth\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Pro video workflows\u003C/td>\u003C/tr>\n                \u003C/tbody>\n            \u003C/table>\n        \u003C/section>\n\n        \u003Csection class=\"step-text-to-image\">\n            \u003Ch2>II. Text-to-Image: Core Scene Plate\u003C/h2>\n            \u003Cp>\u003Cstrong>Goal:\u003C/strong> a modern street corner with \u003Cstrong>no people\u003C/strong>—the base for everything after.\u003C/p>\n            \u003Cp>Open \u003Ca href=\"https://www.fuseaitools.com/home/seedream/5-lite-text-to-image\">Seedream 5 Lite — Text to Image\u003C/a> on FuseAI Tools (\u003Ccode>/home/seedream/5-lite-text-to-image\u003C/code>), paste the prompt and settings below, and generate.\u003C/p>\n\n            \u003Cdiv class=\"code-block\">\n                \u003Cpre>\u003Ccode>{\n  \"prompt\": \"A modern city street corner on a sunny day. A red-brick wedge building on the corner with an old bookstore on the ground floor and a vintage street lamp beside it. Across the street, a glass curtain-wall office tower. Modern cars and pedestrians on the road. Centered composition, 16:9 landscape, photorealistic, ultra sharp.\",\n  \"aspect_ratio\": \"16:9\",\n  \"quality\": \"high\"\n}\u003C/code>\u003C/pre>\n            \u003C/div>\n\n            \u003Cp>\u003Cstrong>Sample output:\u003C/strong>\u003C/p>\n            \u003Cp>\u003Ca href=\"https://media.fuseaitools.com/image/ff7f3be0285d278bc3cc622da732c1b8_1775896723_2otxlf2i_63bb3e6ebc5248b29b1d69ab7c6cf4ee.png\" target=\"_blank\" rel=\"noopener noreferrer\">Open core plate image\u003C/a>\u003C/p>\n            \u003Cdiv class=\"image-container\">\n                \u003Cimg src=\"https://media.fuseaitools.com/image/ff7f3be0285d278bc3cc622da732c1b8_1775896723_2otxlf2i_63bb3e6ebc5248b29b1d69ab7c6cf4ee.png\" alt=\"Core plate: bookstore corner and tower\" width=\"1200\" loading=\"lazy\" style=\"max-width:100%; height:auto;\">\n                \u003Cp class=\"image-caption\">Core plate: locks layout, lens, and light for all following steps\u003C/p>\n            \u003C/div>\n            \u003Cp>\u003Cstrong>Notes:\u003C/strong> this image defines bookstore, lamp, tower, angle, and sun direction—everything downstream keys off it.\u003C/p>\n        \u003C/section>\n\n        \u003Csection class=\"step-img2img-first\">\n            \u003Ch2>III. Image-to-Image: First Frame (Modern + Elder)\u003C/h2>\n            \u003Cp>\u003Cstrong>Goal:\u003C/strong> add modern people and details for the \u003Cstrong>start\u003C/strong> of the clip.\u003C/p>\n            \u003Cp>Open \u003Ca href=\"https://www.fuseaitools.com/home/seedream/5-lite-image-to-image\">Seedream 5 Lite — Image to Image\u003C/a> (\u003Ccode>/home/seedream/5-lite-image-to-image\u003C/code>), upload the \u003Cstrong>core plate from Section II\u003C/strong> as reference, then use:\u003C/p>\n\n            \u003Cdiv class=\"code-block\">\n                \u003Cpre>\u003Ccode>{\n  \"prompt\": \"Keep building layout, camera angle, and lighting exactly the same. On the sidewalk at the corner, add a man in his 70s in a dark trench coat, back to camera, looking up at the glass tower across the street. Replace cars with modern models (Tesla, Toyota). Contemporary city mood, photoreal.\",\n  \"image_urls\": [\"https://media.fuseaitools.com/image/ff7f3be0285d278bc3cc622da732c1b8_1775896723_2otxlf2i_63bb3e6ebc5248b29b1d69ab7c6cf4ee.png\"],\n  \"aspect_ratio\": \"16:9\",\n  \"quality\": \"high\"\n}\u003C/code>\u003C/pre>\n            \u003C/div>\n\n            \u003Cp>\u003Cstrong>Sample output:\u003C/strong>\u003C/p>\n            \u003Cp>\u003Ca href=\"https://media.fuseaitools.com/image/78121a330dc5a4bf20ee54ab02e89af7_1775901058_a1uqp9d9_300bdd84acc141c5ae50e9a9b0e1977f.png\" target=\"_blank\" rel=\"noopener noreferrer\">Open first frame\u003C/a>\u003C/p>\n            \u003Cdiv class=\"image-container\">\n                \u003Cimg src=\"https://media.fuseaitools.com/image/78121a330dc5a4bf20ee54ab02e89af7_1775901058_a1uqp9d9_300bdd84acc141c5ae50e9a9b0e1977f.png\" alt=\"First frame: elder, back to camera\" width=\"1200\" loading=\"lazy\" style=\"max-width:100%; height:auto;\">\n                \u003Cp class=\"image-caption\">First frame: modern “now”—curiosity from the back-facing figure\u003C/p>\n            \u003C/div>\n            \u003Cp>\u003Cstrong>Notes:\u003C/strong> the back view invites “what is he looking at?” and modern cars anchor the present.\u003C/p>\n        \u003C/section>\n\n        \u003Csection class=\"step-img2img-last\">\n            \u003Ch2>IV. Image-to-Image: Last Frame (1950s + Young Adult)\u003C/h2>\n            \u003Cp>\u003Cstrong>Goal:\u003C/strong> same corner, new era—\u003Cstrong>end frame\u003C/strong> for the video.\u003C/p>\n            \u003Cp>Stay on \u003Ca href=\"https://www.fuseaitools.com/home/seedream/5-lite-image-to-image\">Seedream 5 Lite — Image to Image\u003C/a> (\u003Ccode>/home/seedream/5-lite-image-to-image\u003C/code>), upload the \u003Cstrong>same core plate\u003C/strong> as in Section III, then:\u003C/p>\n\n            \u003Cdiv class=\"code-block\">\n                \u003Cpre>\u003Ccode>{\n  \"prompt\": \"Keep layout, angle, and light direction the same. Shift the scene to the 1950s: bookstore sign in retro lettering; lamp unchanged but warmer glow; glass tower reads as brick. Add a 25-year-old man in vintage suit and hat, smiling. Replace cars with classic 1950s (e.g. Chevrolet Bel Air). Warm yellow grade, film texture.\",\n  \"image_urls\": [\"https://media.fuseaitools.com/image/ff7f3be0285d278bc3cc622da732c1b8_1775896723_2otxlf2i_63bb3e6ebc5248b29b1d69ab7c6cf4ee.png\"],\n  \"aspect_ratio\": \"16:9\",\n  \"quality\": \"high\"\n}\u003C/code>\u003C/pre>\n            \u003C/div>\n\n            \u003Cp>\u003Cstrong>Sample output:\u003C/strong>\u003C/p>\n            \u003Cp>\u003Ca href=\"https://media.fuseaitools.com/image/c5ac3f2a3efa7df1d8fed07f9a1ef34d_1775901232_x2wm1dpv_81e3ca1d9859444f8ec43b9f0cbcb426.png\" target=\"_blank\" rel=\"noopener noreferrer\">Open last frame\u003C/a>\u003C/p>\n            \u003Cdiv class=\"image-container\">\n                \u003Cimg src=\"https://media.fuseaitools.com/image/c5ac3f2a3efa7df1d8fed07f9a1ef34d_1775901232_x2wm1dpv_81e3ca1d9859444f8ec43b9f0cbcb426.png\" alt=\"Last frame: 1950s corner and young man\" width=\"1200\" loading=\"lazy\" style=\"max-width:100%; height:auto;\">\n                \u003Cp class=\"image-caption\">Last frame: retro mood; geometry matches the first frame\u003C/p>\n            \u003C/div>\n            \u003Cp>\u003Cstrong>Notes:\u003C/strong> silhouette, lamp position, and POV align with Section III—only era, wardrobe, and cars change. That gives I2V a clean anchor.\u003C/p>\n        \u003C/section>\n\n        \u003Csection class=\"step-image-to-video\">\n            \u003Ch2>V. Image-to-Video: The Transition\u003C/h2>\n            \u003Cp>\u003Cstrong>Goal:\u003C/strong> feed first and last frames so the model interpolates from modern to retro.\u003C/p>\n            \u003Cp>Open \u003Ca href=\"https://www.fuseaitools.com/home/seedance/v1-lite-image-to-video\">Seedance v1 Lite — Image to Video\u003C/a> (\u003Ccode>/home/seedance/v1-lite-image-to-video\u003C/code>), set \u003Cstrong>start image\u003C/strong> and \u003Cstrong>end image\u003C/strong>, then align prompt and settings with your API/UI (resolution, duration, fixed camera, etc.).\u003C/p>\n\n            \u003Cdiv class=\"code-block\">\n                \u003Cpre>\u003Ccode>{\n  \"prompt\": \"Fixed camera on the same corner. Opens in the modern city with an elderly man at the curb. Light warms; modern cars morph into classics; glass tower becomes brick; bookstore sign turns retro. The man grows younger—hair darkens, trench becomes a vintage suit. Ends in the 1950s with the young man smiling into the distance. Smooth, cinematic, film-like color.\",\n  \"image_url\": \"https://media.fuseaitools.com/image/78121a330dc5a4bf20ee54ab02e89af7_1775901058_a1uqp9d9_300bdd84acc141c5ae50e9a9b0e1977f.png\",\n  \"end_image_url\": \"https://media.fuseaitools.com/image/c5ac3f2a3efa7df1d8fed07f9a1ef34d_1775901232_x2wm1dpv_81e3ca1d9859444f8ec43b9f0cbcb426.png\",\n  \"resolution\": \"1080p\",\n  \"duration\": \"10\",\n  \"camera_fixed\": true,\n  \"seed\": -1\n}\u003C/code>\u003C/pre>\n            \u003C/div>\n\n            \u003Cp>\u003Cstrong>Sample output:\u003C/strong>\u003C/p>\n            \u003Cp>\u003Ca href=\"https://media.fuseaitools.com/video/97516ac4f65fdf3cab2424c1f4c64ce0_1775985154_fk1ct6n0_e88da5b1dfbe4afcaa93800ed49b2696.mp4\" target=\"_blank\" rel=\"noopener noreferrer\">Open sample MP4\u003C/a>\u003C/p>\n            \u003Cdiv class=\"video-container\" style=\"position:relative;width:100%;max-width:100%;aspect-ratio:16/9;background:#0f172a;border-radius:8px;overflow:hidden;margin:1rem 0;\">\n                \u003Cvideo class=\"article-video\" controls playsinline preload=\"metadata\" poster=\"https://media.fuseaitools.com/image/78121a330dc5a4bf20ee54ab02e89af7_1775901058_a1uqp9d9_300bdd84acc141c5ae50e9a9b0e1977f.png\" style=\"position:absolute;left:0;top:0;width:100%;height:100%;object-fit:contain;display:block;\">\n                    \u003Csource src=\"https://media.fuseaitools.com/video/97516ac4f65fdf3cab2424c1f4c64ce0_1775985154_fk1ct6n0_e88da5b1dfbe4afcaa93800ed49b2696.mp4\" type=\"video/mp4\">\n                    Your browser does not support the video tag.\n                \u003C/video>\n            \u003C/div>\n            \u003Cp class=\"image-caption\">Sample: modern-to-retro time travel in one take\u003C/p>\n\n            \u003Cp>\u003Cstrong>Quality snapshot:\u003C/strong>\u003C/p>\n            \u003Ctable style=\"width:100%; border-collapse:collapse; margin:1rem 0;\">\n                \u003Cthead>\n                    \u003Ctr style=\"border-bottom:1px solid #e5e7eb;\">\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Dimension\u003C/th>\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Rating\u003C/th>\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Comment\u003C/th>\n                    \u003C/tr>\n                \u003C/thead>\n                \u003Ctbody>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Transition smoothness\u003C/td>\u003Ctd style=\"padding:0.5rem;\">⭐⭐⭐⭐⭐\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Aligned geometry and light\u003C/td>\u003C/tr>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Era shift\u003C/td>\u003Ctd style=\"padding:0.5rem;\">⭐⭐⭐⭐⭐\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Cars, façades, wardrobe evolve naturally\u003C/td>\u003C/tr>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Character morph\u003C/td>\u003Ctd style=\"padding:0.5rem;\">⭐⭐⭐⭐\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Elder→youth reads well; slight dreamlike feel\u003C/td>\u003C/tr>\n                    \u003Ctr>\u003Ctd style=\"padding:0.5rem;\">Emotion\u003C/td>\u003Ctd style=\"padding:0.5rem;\">⭐⭐⭐⭐⭐\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Nostalgic “rewind time” beat\u003C/td>\u003C/tr>\n                \u003C/tbody>\n            \u003C/table>\n            \u003Cp>\u003Cstrong>Good fits:\u003C/strong> city promos, heritage brand stories, before/after place marketing, nostalgic short-form.\u003C/p>\n        \u003C/section>\n\n        \u003Csection class=\"advantages\">\n            \u003Ch2>VI. Why This Pipeline Works\u003C/h2>\n            \u003Ctable style=\"width:100%; border-collapse:collapse; margin:1rem 0;\">\n                \u003Cthead>\n                    \u003Ctr style=\"border-bottom:1px solid #e5e7eb;\">\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Strength\u003C/th>\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Why it matters\u003C/th>\n                    \u003C/tr>\n                \u003C/thead>\n                \u003Ctbody>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Consistency\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Both keyframes inherit one plate—framing and light lock\u003C/td>\u003C/tr>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Control\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Tune each step without breaking the others\u003C/td>\u003C/tr>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Efficiency\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Generate the plate once; reuse for many variants\u003C/td>\u003C/tr>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Natural motion\u003C/td>\u003Ctd style=\"padding:0.5rem;\">The model only models change, not guessing a new set\u003C/td>\u003C/tr>\n                    \u003Ctr>\u003Ctd style=\"padding:0.5rem;\">Extensible\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Same plate → seasons, day/night, style passes, etc.\u003C/td>\u003C/tr>\n                \u003C/tbody>\n            \u003C/table>\n        \u003C/section>\n\n        \u003Csection class=\"advanced\">\n            \u003Ch2>VII. More Ideas From One Plate\u003C/h2>\n            \u003Cp>Reuse the same core image for other stories:\u003C/p>\n            \u003Ctable style=\"width:100%; border-collapse:collapse; margin:1rem 0;\">\n                \u003Cthead>\n                    \u003Ctr style=\"border-bottom:1px solid #e5e7eb;\">\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Variation\u003C/th>\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Prompt cues\u003C/th>\n                        \u003Cth style=\"text-align:left; padding:0.5rem;\">Use case\u003C/th>\n                    \u003C/tr>\n                \u003C/thead>\n                \u003Ctbody>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Seasons\u003C/td>\u003Ctd style=\"padding:0.5rem;\">“Winter snow, coats, gray sky”\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Four-season campaign\u003C/td>\u003C/tr>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Day / night\u003C/td>\u003Ctd style=\"padding:0.5rem;\">“Neon at night, moonlight on wet asphalt”\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Day vs night city edit\u003C/td>\u003C/tr>\n                    \u003Ctr style=\"border-bottom:1px solid #f3f4f6;\">\u003Ctd style=\"padding:0.5rem;\">Style\u003C/td>\u003Ctd style=\"padding:0.5rem;\">“Studio Ghibli-inspired, warm and painterly”\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Stylized short\u003C/td>\u003C/tr>\n                    \u003Ctr>\u003Ctd style=\"padding:0.5rem;\">Character\u003C/td>\u003Ctd style=\"padding:0.5rem;\">“Couple hugging at the corner”\u003C/td>\u003Ctd style=\"padding:0.5rem;\">Emotional spot\u003C/td>\u003C/tr>\n                \u003C/tbody>\n            \u003C/table>\n        \u003C/section>\n\n        \u003Csection class=\"conclusion\">\n            \u003Ch2>VIII. Wrap-Up\u003C/h2>\n            \u003Cp>\u003Cstrong>Core plate → first frame → last frame → video\u003C/strong> is a repeatable way to get pro-looking time-travel shorts: lock what stays fixed, then let the model handle change.\u003C/p>\n            \u003Cp>\u003Cem>City Then & Now\u003C/em> is one template—the same corner can spin into seasons, day/night, or style studies. Experiment on \u003Ca href=\"https://www.fuseaitools.com/home/seedream/5-lite-text-to-image\">Seedream 5 Lite (Text to Image)\u003C/a>, \u003Ca href=\"https://www.fuseaitools.com/home/seedream/5-lite-image-to-image\">Image to Image\u003C/a>, and \u003Ca href=\"https://www.fuseaitools.com/home/seedance/v1-lite-image-to-video\">Seedance v1 Lite (Image to Video)\u003C/a>.\u003C/p>\n        \u003C/section>\n    \u003C/article>\n\u003C/body>\n\u003C/html>","","claude-opus-4.5-vs-claude-opus-4.6","2026-04-12 09:58:42",1775988110361]