3D地圖式擴增實境實作研究—以醫院導航、歷史文化場域、智慧生產線為例

隨著元宇宙的熱潮，AR與VR再次受到大眾的關注，激起相關產業與學術單位投入AR/VR的開發與研究。目前對於AR應用的開發已推出不少工具，其中定位技術的已經常見的圖像式定位發展到可辨識現實環境進行定位的「3D地圖式定位技術」，而「3D地圖式定位技術」這個新穎的技術在應用才剛開始起步，當要開發「3D地圖式定位技術」相關的AR應用時，該如何從不同優缺點的開發工具之中，快速選擇到最適合的開發工具？且在沒有開發「3D地圖式定位技術」的經驗下，如何避免或解決將會面臨到的問題？因此本研究目標是分析整理現有的「3D地圖式定位技術」開發工具，進而比較各自的優缺點，並以實作三個不同性質的案例作為前車之鑑，提供未來學者與研究者進行相關研究時的參考。

本研究首先探討具有「3D地圖式定位技術」且支援Unity作為開發引擎的四個開發工具Vuforia、Wikitude、Spatial Anchor與ARWayKit的開發流程後，以「3D定位地圖建構方式」、「3D定位地圖存放位置」與「AR內容編輯處」三項重點分析四個開發工具，透過分析結果進行四個開發工具的優缺點比較，最終選定Vuforia作為下一階段案例實作的主要開發工具。選定開發工具後，開始進行三項實作案例的實作，三項案例分別為:代表歷史文化場域旅遊導覽的「光復新村AR」; 代表智慧生產線應用的「製鞋智動化AR資訊應用」; 代表醫院(室內)導航的「中山醫院院內導航APP」，透過開發三個案例的實作經驗與結果測試之後，可得知3D地圖式AR定位技術適用於室內或者小範圍的AR體驗，其定位效果佳，且使用者無需尋找特定的圖像，僅需透過行動裝置的攝影鏡頭環繞周圍的實體環境，就可開始使用AR服務，但在「光復新村AR」的案例之下，戶外的大範圍旅遊導覽使用Vuforia Area Target則會因為3D定位地圖拼接、現場環境光源與未保持定位的情況下設備持續移動，造成AR內容定位產生偏移的問題，且在Vuforia的運作機制之下，3D定位地圖存放在手機本地端進而衍生出的APP容量較大的顧慮。
最後則提出「AR內容定位偏移」與「APP容量較大」兩項問題的建議解決方法。在大範圍的環境下使用手機裝置製作3D定位地圖，會遇到單個3D定位地圖容量限制的問題，因此只能針對重點區域(如光復新村AR中的導覽點) 製作3D定位地圖，並利用對位拼接的方式將各個3D定位地圖合併，拼接過程中便有可能產生偏差，因此提出使用專業的3D掃描儀器，將整個環境建置成一張3D定位地圖，便可以避免拼接時而產生的誤差。而「APP容量較大」的問題便是由APP之中的3D定位地圖與AR內容的容量堆積而成，遵循Vuforia Area Target 3D定位地圖必須儲存在APP之中的規則，在此提出將AR虛擬內容雲端化的解決方法，此方法可以透過雲端儲存資料的方式，將所有AR的虛擬內容移出APP，在需要時利用下載與載入將AR虛擬內容顯示出來。

With the trend of metaverse, AR and VR are once again attracting public attention and stimulating related industries and academic units to invest in the development and research of AR/VR. At present, many tools have been launched for the development of AR applications, among which the positioning technology has been developed from the common image-based positioning to the "3D world map-based positioning technology" which can recognize the real environment for positioning, this novel technology is just starting to take off in terms of applications. When developing AR applications related to "3D world map-based positioning technology", how to quickly select the most suitable development tool from among the development tools with different advantages and disadvantages? And how to avoid or solve the problems that will be faced when there is no experience in developing "3D world map-based positioning technology"? This paper take the above two points as research questions, and aim to analyze and organize the existing "3D world map-based positioning technology" development tools, and then compare their respective advantages and disadvantages, and use three cases of different nature as a precedent to provide reference for future scholars and researchers to conduct relevant research and development.

This study firstly explore the development process of four development tools with "3D world map-based positioning technology" and supporting Unity as the development engine, Vuforia, Wikitude, Spatial Anchor, and ARWayKit, and then analyze the four development tools with three main points: "3D positioning world map construction method", "3D positioning world map storage location", and "AR content editing place". "After analyze the four development tools, we compare the advantages and disadvantages of the four development tools through the analysis results, and finally select Vuforia as the main development tool for the next phase of the case study. After the development tools are selecte, we start the implementation of the three case studies. The three cases are: "Guangfu Village AR" for historical and cultural tourism; "Shoemaking AR Information Application" for smart production line application; and "Zhongshan Hospital in-door Navigation App" for in-door Application navigation. AR positioning technology is suitable for indoor or small area AR experience, and its positioning effect is good, and users do not need to find a specific image, but only need to surround the surrounding physical environment through the camera of mobile devices to start using AR services. However, in the case of "Guangfu Village AR", the use of Vuforia Area Target for a large outdoor tour will cause the problem of shifting AR content positioning due to the stitching of the map, the continuous movement of the device under the circumstances of the ambient light source and the failure to maintain positioning.

Finally, we propose two solutions to the problems of "AR content positioning offset" and "large app capacity". When using mobile devices to create 3D positioning world maps in a large area, there is a limitation of the capacity of a single 3D positioning world map, so we can only create 3D positioning maps for the key areas (e.g., the navigation points in Guangfu Village AR) and combine the 3D positioning world maps by alignment stitching. Therefore, we propose to use a professional 3D scanner to build the whole environment into a 3D positioning world map, which can avoid the error caused by stitching. The problem of "large capacity of APP" is cause by the accumulation of 3D positioning world map and AR virtual content in APP, which follows the rule that Vuforia Area Target 3D positioning world map must be stored in APP. This paper proposes move all the AR virtual contents out of the APP by storing data in the cloud, and display the AR virtual contents by downloading and loading when needed.