You can achieve AR effects on large structures using Lightship VPS. This would require users to localize at specific locations/Wayspots and that you offset AR content from those locations to-scale in 3D modeling software. Information of Lightship VPS here: 8th Wall.
As an example of augmenting large structures with VPS, I augmented Coit Tower in San Francisco by scanning the staircase at the base of the structure and had users localize against that. A preview of the mesh I scanned and used for localization below:
Note that all users had to begin the experience at this specific location - they couldn’t just look at the tower from any ambiguous spot around the tower.
After scanning the entrance staircase, I brought it into blender and scaled a 3D model of coit tower to align with the scan. I baked a simple animation, then exported the coit tower model and animation separately. I added the animation and the mesh (with xrextras-hider-material) to my wayspot in the same manner as the VPS bespoke sample project. Please review the documentation in this sample project for more detailed information on developing VPS experiences.
The final result is attached as a video.
I will note that it took me a couple of tries to get it aligned perfectly. Accuracy is pretty noticeable at a large distance. The closer you can localize to the structure, the better.
I found it useful to add an opacity slider which overlayed the 3D model of tower to help understand how different angles compared in localization accuracy and to help find the best place to localize.
Hope this points you in the right direction
