coarseDepthTestDistance
The distance from the camera, beyond which, billboards are depth-tested against an approximation of the globe ellipsoid rather than against the full globe depth buffer. When set to 0, the approximate depth test is always applied. When set to Number.POSITIVE_INFINITY, the approximate depth test is never applied.
This setting only applies when a billboard's Billboard.disableDepthTestDistance value would otherwise allow depth testing—i.e., distance from the camera to the billboard is less than a billboard's Billboard.disableDepthTestDistance value.