Skyscraper Surface Test

This test allows you to view skyscraper buildings from different distances on both a flat surface and a spherical surface as you travel along the surface. Both cameras are 6 feet above the surface. The sphere has a circumference of 24,901 miles which is the equivalent of the earth at the equator.

Each building is exactly the same size which is 1,966 feet tall and 197 feet in width and depth. This is very similar in size to the Ping An International Finance Centre in Shenzhen, Guangdong, China which is the 5th tallest building in the world. The buildings are very simple and use only a basic color material. This is to prevent possible performance issues and allow the demo to run on as many devices as possible.

The buildings are placed in pairs. One building 1,500 feet left of center and the other 1,500 feet right of center. Each pair is separated by 25 miles. At 50 miles, there should be approximately 1,666.67 feet missing due to curvature. Since our eyesight/camera level is 6 feet above the surface, there should be approximately 1,473.1 feet missing according to the Omni Earth Curvature Calculator. The sphere surface hides the bottom of the building as expected but the flat surface shows what we actually see in the real world.

The standard explanation for seeing too far is refraction. If this were true, then gyroscopes would not work as expected on airplanes while flying over the curve. A gyroscope is rigid in space which means it will maintain its orientation regardless of any movement of the surrounding structure (aka airplane). It is not affected by gravity.

A link to the test is below along with a babylon.js playground link if you would like to view the code and experiment with it yourself.

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