Dilates frustum planes outward by margin world meters, for the preload ring:
tiles within margin of the real frustum (just off-screen) pass the dilated test
and get their content warmed, so a quick pan doesn't reveal an unloaded hole. With
normalized inward-normal planes (n·w + d ≥ 0 inside), pushing a plane out by m
is just d += m. Returns the input array unchanged when margin ≤ 0.
Dilates frustum planes outward by
marginworld meters, for the preload ring: tiles withinmarginof the real frustum (just off-screen) pass the dilated test and get their content warmed, so a quick pan doesn't reveal an unloaded hole. With normalized inward-normal planes (n·w + d ≥ 0inside), pushing a plane out bymis justd += m. Returns the input array unchanged whenmargin ≤ 0.