{"schemaVersion":1,"record":{"key":"mechanic/phone-flashlight--family-movement","type":"mechanic","id":"phone-flashlight--family-movement","lang":"en","title":"Direction and movement of the phone","summary":"Moving the phone changes object lighting. The WildLight research prototype uses images with a moving LED to recover shape and reflectance.","updatedAt":"2026-10-22","status":"active","url":"https://gamemechanics.pro/en/knowledge/mechanic/phone-flashlight--family-movement/","jsonUrl":"https://gamemechanics.pro/api/v1/knowledge/en/mechanic/phone-flashlight--family-movement.json","markdownUrl":"https://gamemechanics.pro/content/knowledge/en/mechanic/phone-flashlight--family-movement.md","aliases":[],"tags":["Phone flashlight interactions","Mechanics catalog"],"sourceIds":["source-486438ca6bfacdc6"],"sources":[{"id":"source-486438ca6bfacdc6","title":"WildLight (research prototype)","url":"https://junxuan-li.github.io/wildlight-website/","verifiedAt":null}],"sections":[{"id":"principle","title":"How it works","body":"Posture, speed and trajectory turn the phone into a handheld tool."},{"id":"variants","title":"Variants","body":"### Variants and applications\n\n<a id=\"family-movement-variants\"></a>\n\n- Targeting. Action: Align the direction of the phone with the target. Application: AR pointer, exhibit selection, virtual spotlight. Requirements: Rear LED and app control; Motion sensors and calibration; Camera and spatial tracking; Software game rule. Conditions: Sensors provide orientation; binding to a specific real goal requires tracking or a tag. <a id=\"variant-21\"></a>\n- Direction hold. Action: Do not move the phone out of the permissible angle for a specified time. Application: Stabilize the signal, study a virtual object, play for accuracy. Requirements: Rear LED and control from the application; Motion sensors and calibration; Software game rule. Conditions: It is possible to evaluate stability relative to the initial pose without recognizing the room. <a id=\"variant-22\"></a>\n- Tracking a moving target. Action: Rotate the phone after the object. Application: Accompanying a virtual creature, guarding a moving load. Requirements: Rear LED and control from the application; Motion sensors and calibration; Camera and proprietary image analysis; Software game rule. Conditions: The real target requires video tracking; the game itself knows the virtual target... <a id=\"variant-23\"></a>\n- Search by sector. Action: Consistently illuminate the directions around the initial pose. Application: In-game room scanner, overview of hidden virtual threats. Requirements: Rear LED and control from the application; Motion sensors and calibration; Software game rule. Conditions: Gyroscope needs calibration; it does not confirm that actual surfaces have been inspected. <a id=\"variant-24\"></a>\n- Outline outline. Action: Swipe the phone along a given line. Application: Drawing a symbol, setting up an antenna, restoring a picture. Requirements: Rear LED and control from the application; Motion sensors and calibration; Software game rule. Conditions: Without a camera, a corner path is recognized, not a line on the wall. <a id=\"variant-25\"></a>\n- Passage speed control. Action: Pass the light slowly or quickly without leaving the range. Application: Virtual scanning, image “developing”, musical glissando. Requirements: Rear LED and control from the application; Motion sensors and calibration; Software game rule. Conditions: Angular velocity can be estimated by sensors; the speed of the light spot requires the geometry of the scene. <a id=\"variant-26\"></a>\n- Order of directions. Action: Shine up, down, left and right in the desired order. Application: Spatial password, dance team, ritual. Requirements: Rear LED and app control; Motion sensors and calibration; Software game rule. Conditions: Fix the frame of reference and tolerances before the start of the round. <a id=\"variant-27\"></a>\n- Rotation around an axis. Action: Rotate the phone like a dial, maintaining the direction. Application: Select a conditional filter, scanner frequency or instrument mode. Requirements: Rear LED and control from the application; Motion sensors and calibration; Software game rule. Conditions: Program mode changes; the actual LED spectrum does not change depending on rotation. <a id=\"variant-28\"></a>\n- Approaching the surface. Action: Change the distance to the object and the size of the illuminated area. Application: Selecting the scale of the shadow, examining the texture, AR task at a distance. Requirements: Rear LED and control from the application; Prepared props or external sensor; Camera and proprietary image analysis. Conditions: Automatic distance estimation requires a known marker, tracking or depth sensor. <a id=\"variant-29\"></a>\n- Moving the source to a new point. Action: Move the phone relative to the object, and not just turn it. Application: Study the relief from the other side, get the desired shadow, explore the scene. Requirements: Rear LED and control from the application; Prepared props or external sensor; Camera and spatial tracking. Conditions: The actual displacement can be seen by a person; Coordinates for the game require positional tracking. <a id=\"variant-30\"></a>"},{"id":"context","title":"Context and limits","body":"Author's working classification for designing games and interactions. Options can overlap and combine; the list is not a generally accepted standard or proven exhaustive list. Application examples are conditional unless a specific verifiable observation is indicated nearby. Sources support individual techniques and technical limitations."}],"relations":[],"placements":[{"catalogId":"phone-flashlight","id":"family-movement","title":"Phone flashlight interactions","url":"https://gamemechanics.pro/en/mechanics/phone-flashlight/#family-movement","categoryIds":["section-1"]}],"supersededBy":[],"attributes":{"preview":{"updatedAt":"2026-10-22","title":"Direction and movement of the phone","description":"Moving the phone changes object lighting. The WildLight research prototype uses images with a moving LED to recover shape and reflectance.","image":{"src":"images/mechanics/flash-wildlight.webp","width":1440,"height":387,"crop":{"x":285,"y":0,"width":283,"height":132},"game":"WildLight (research prototype)","sourceUrl":"https://junxuan-li.github.io/wildlight-website/","originalUrl":"https://junxuan-li.github.io/wildlight-website/static/images/teaser.jpg","credit":"Ziang Cheng, Junxuan Li, Hongdong Li","rights":"© Ziang Cheng, Junxuan Li, Hongdong Li. Author-distributed research figure; respective rights retained. Excluded from portal MIT and CC BY 4.0.","caption":"WildLight: an object photographed using the phone flashlight","alt":"WildLight: an object photographed using the phone flashlight","markers":[{"x":29,"y":24,"label":"The flashlight image shows changed lighting on the model car"}]},"tips":["Distinguish device orientation, light position and the camera-visible light patch."],"examples":[{"title":"WildLight (research prototype)","url":"https://junxuan-li.github.io/wildlight-website/"}]}},"endsAt":null,"provenance":"Original editorial design catalog consolidated from project discussions on 2026-10-20. Complete discussion item lists and contextual limitations are preserved; linked primary sources support specific techniques, not the entire classification. English translation was prepared with machine assistance and editorial review.","license":"CC-BY-4.0","codeLicense":"MIT","attribution":"gamemechanics.pro contributors","catalogKey":"catalog/phone-flashlight"}}