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Commonly asked questions about Google Maps Platform’s recently launched Photorealistic 3D Tiles


Editor’s Note: Since the launch of our Experimental Photorealistic 3D Tiles at I/O in May, Google Maps Platform has been thrilled to see all of the developer excitement and demos featuring the product. They’ve also received a lot of questions from developers. Together with Lisa Bos, Senior Product Manager at Cesium, their highlighting the most commonly asked questions they’ve received from developers.


Why is the quota so low? Can I get more quota?

Danbi: Google Maps Platform products that are in the Experimental phase, such as the Photorealistic 3D Tiles, will often have lower default daily quota limits per project. During this phase we’re testing out your response based on the use cases you’re trying out. We know now that the quota limit on the individual tile requests have been limiting for some of you, so we’re re-thinking these limits for the next launch stage, Preview.


Is it free to use?

Danbi: Google Maps Platform products that are in the Experimental phase, such as Photorealistic 3D Tiles, are free to use during the Experimental phase, but with the limited quota cap as mentioned above. The purpose of this launch phase is to gather feedback from the developer community prior to previewing the product. Your feedback, demos, questions, and public issue trackers are very important to us, so please keep the feedback coming!


However, during Preview we generally share product pricing information and customers will be billed at a 100% discount during this launch stage. If you’ve already set up your billing account, no further action is necessary, your API key will continue to work. This is to give you time to adjust your products and usage before we move out of Preview and into General Availability.


Lisa: Developers will want to apply a thoughtful strategy for managing Map Tiles API sessions and requests. During the Preview launch stage, Cesium will provide guidance to help you understand how implementation choices impact your data usage when using CesiumJS and our other runtimes. When that becomes available, we'll let you know on our community forum.


Why do we need to attribute the map and what attributions are required?

Danbi: We’re really energised by the number of developers that have been testing out the product, and know that it’s easy to forget about proper attribution in that excitement. We get it! However, attribution is part of the use agreement in our Terms of Service and the Map Tiles API Policies, and generally considered standard cartographic practice.


An example of brand attribution and data attribution


There are two types of important attributions: brand attribution and data attribution. Brand attribution requires you to display the Google logo whenever you display our maps or imagery in your visualisation. Data attribution requires you to display the data providers that the imagery is sourced from. As you have seen in our own Google Maps applications, our imagery is sourced by Google as well as other providers. In your visualisations, as your user moves around the map, the API will send updated data attribution strings to the renderer based on what’s in the viewport.


We know that the guidelines around how to attribute can be unsuitable for some of your use cases, especially where it might impact your user experience that isn’t a standard or traditional ‘map’ visualisation, and more of a cinematic experience. To address these issues, we’ll provide some additional guidance on alternative attribution methods when we move to Preview.


Lisa: Each of Cesium’s runtimes (CesiumJS, Cesium for Unity, Cesium for Unreal, and Cesium for Omniverse) provide a way to display logos and data attribution. If you're working with CesiumJS, the method to add a logo is documented here. By default, the logo will be added in the lower left, and the Data attribution link will be shown to its right. You can use CSS to change the logo and attribution placement and appearance.


Can the street level geometry be more refined?

Danbi: Generally speaking, the 3D mesh model is generated procedurally using photogrammetric methods with flat imagery. There’s a lot more complex math to it, but this results in less precise modeling of the real world at the pedestrian-scale. For example, you may see parked cars or awnings melted into the mesh, or sometimes tree canopies get modeled as floating objects. We’d love to continue hearing your feedback on how to improve the Photorealistic 3D Tiles.


Can I use it for precise measurements? Can I get the elevation info or other attribution?

Danbi: The Photorealistic 3D Tiles are not considered ‘survey-grade’ at this time. The original intent of the product is to power immersive visualisations, rather than support spatial analysis or model measurements. Also note that programmatically reading and recording measurements (heights, distances, elevations, etc.) from our 3D imagery is considered derivative and is prohibited. For details, in addition to our Terms of Service, please read our Policies page on “Pre-Fetching, Caching, or Storage of Content” where we explicitly state that any “image analysis, machine interpretation, object detection/identification, geodata extraction or resale, offline uses, including any of the above” based off of our imagery data is not allowed.


Lisa: Developers can use Cesium to combine the current release of Photorealistic 3D Tiles with other data to support some use cases like those Danbi described above. In this example, a precise building model is visualised in context provided by Photorealistic 3D Tiles. Your own metadata can also be added to and visualised with Cesium apps. Check out this Cesium Stories tutorial for a simple example.


Can we use Cesium World Terrain with Google’s Photorealistic 3D Tiles?

Danbi: Any geodata that may be considered ‘survey-grade’ or have hyper local precision and alignment accuracy will exhibit some offset from our Photorealistic 3D Tiles, as it is currently based off of a Google’s datum. That is another reason why today it is not considered survey-grade. However, we’re seeking feedback from the developer community on how important standard datum alignment is for your use cases.


Lisa: Due to the differences in the reference system used by Photorealistic 3D Tiles and Cesium World Terrain, at this time, we don’t recommend you use them together. And you shouldn’t need to. You can hide the globe (Cesium World Terrain) as shown in this example.


Get in touch with us today to find out how your business can benefit from Google Maps Platform’s different use cases.


(Source: https://cloud.google.com/blog/products/maps-platform/commonly-asked-questions-about-our-recently-launched-photorealistic-3d-tiles)

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