aboveModelSharefunction

The share of the view's height that a model's radius takes when the camera is distanceKm above the satellite (a ride above it). A satellite is a few metres across, so the model is drawn larger than it is, but a model that stays a share of the picture at any height becomes a block thousands of kilometres across from far up. So the model keeps a fixed size in the world, about 16 km in radius, which is the share ABOVE_MODEL_SHARE at ABOVE_MODEL_KM: it is never larger than that, falls as one over the height above it, and from MODEL_FADE_FROM_KM is let down smoothly (a smooth step) to nothing at MODEL_FADE_TO_KM, where the satellite is its ordinary mark. Pure, so a test can ask it at any height.

import { aboveModelShare } from "@johnmorrisdotca/chikyu-earth/space";

function aboveModelShare(distanceKm: number, lowest?: number): number

import { aboveModelShare } from "@johnmorrisdotca/chikyu-earth/space";

console.log(aboveModelShare(150), aboveModelShare(1000) < aboveModelShare(150), aboveModelShare(6000));

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