What is the optimum 3Dtiles area for creating 3D city environment

1. A concise explanation of the problem you're experiencing.

Hi, We are trying to publish a city environment in cesium using 3DTiles. We have tried firstly to create a single 3DTiles file using only buildings (not including surface). Total file size of our 3DTiles is about 100 MB and contains about 27000 buildings. Our first tests on local Apache server is not bad, but it is not well optimized for internet usage. http://nrw.virtualcitymap.de/ is a good sample for optimizing a 3D city model and dividing (i guess its called as culling) a city into 3DTiles. Also we want to make a similar app using 3DTiles children and grant-children elements.

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

We need to publish 3DTiles on web without any performance decrease. Do you suggest any standard size for culling 3DTiles for large cities? (For exp. we are trying now a 500 x 500 meters 3Dtiles with 2000 x 2000 meters parent content.)

4. The Cesium version you're using, your operating system and browser.

Cesium version 1.39 on Google Chrome and Firefox browsers

30 Kasım 2017 Perşembe 11:40:46 UTC+3 tarihinde murat...@gmail.com yazdı:

1. A concise explanation of the problem you're experiencing.

Hi, We are trying to publish a city environment in cesium using 3DTiles. We have tried firstly to create a single 3DTiles file using only buildings (not including surface). Total file size of our 3DTiles is about 100 MB and contains about 27000 buildings. Our first tests on local Apache server is not bad, but it is not well optimized for internet usage. http://nrw.virtualcitymap.de/ is a good sample for optimizing a 3D city model and dividing (i guess its called as culling) a city into 3DTiles. Also we want to make a similar app using 3DTiles children and grant-children elements.

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

We need to publish 3DTiles on web without any performance decrease. Do you suggest any standard size for culling 3DTiles for large cities? (For exp. we are trying now a 500 x 500 meters 3Dtiles with 2000 x 2000 meters parent content.)

4. The Cesium version you're using, your operating system and browser.

Cesium version 1.39 on Google Chrome and Firefox browsers

As an additional question: What is the most commonly used bounding volume for parent contents? (Sphere, Region or Box)
Or which one will provide more performance while zooming and panning in Cesium?

For determining how to tile building data it comes down to a balance between file sizes and dimensions. You could look at the bounding volumes in https://cesiumjs.org/Cesium/Build/Apps/Sandcastle/?src=3D%20Tiles%20Inspector.html&label=3D%20Tiles (with Display -> Bounding Volumes checked) to get an idea of reasonable bounding volume sizes. The inspector is very handy for seeing performance stats in action.

Regions and boxes are good choices usually. Regions are converted to boxes under the hood. Spheres are generally faster for bounding volume checks but also don’t enclose their contents as tightly so are more likely to be seen even when the contents are out of view. I’d say regions are often the most intuitive for city tilesets.