[Closed] distance from a moving object

Ok, imagine many objects in a scene, then a SphereDummy moving trough the scene. When object is in the sphere radius a keyframe is created in visibility then another 15 frame later with a new visibility value. Basically the SphereDummy contact with object make them appear.
I just can’t find a good basis for detecting distance along the time…
I am learning So I need some help. Thank you.

here is my very start:

for o in objects do
(o.visibility = bezier_float()

with animate on
(–rndm = random 0 10
fr1 =
duration = 15

            at time (fr1) o.visibility.controller.value = 0
            at time (fr1+duration) o.visibility.controller.value = 1
        )
)

… of course if you want to make kinda “fade in – fade out” effect you have to check the distance for less and more, and create keys for both conditions if it’s necessary.

oops… my bad…
of course it must be obj.visibility = … — (not obj.visible)

interested in second case… but i m lost!!

this doesn’t work

for o in objects where (d = distance o $SphereGizmo01) < 50 do
(with animate on
(

        for f=0 to 50 do at time f o.visibility.controller.value = 0
        for f=0 to 50 do at time f+ 15 o.visibility.controller.value = 1
        )
    )

lets define the task more exactly…

1. we have a list of static objects and one moving object
2. every object from the list has bezier float type of visibility controller
3. if the distance between some object from the list and the moving object becomes less then something it sets visibility of the object to 0 (step key)
4. any object from the list can’t stay invisible longer then 15 frames (or has to stay invisible during 15 frames).

am i right?

ok… we have to bake visibility animation based on the moving object animation on current animation range interval…

1. apply bezier float controller to visibility track of every object of the list
   for obj in list do
   (
   obj.visibility.track = bezier_float()
   deletekeys obj.visibility.track #allkeys
   obj.visibility = 1.0 – make visible by default
   )
2. create pair of visibility keys (hide/unhide) for objects which are closer then something to the moving object
   for t=animationrange.start to animationrange.end do at time t
   for obj in list where (d = distance obj moving_obj) < something do
   (
   – check if visibility of this obj is not already animated (skip if it’s already hidden)
   if obj.visibility >= 1.0 do
   (
   – hide
   k0 = addnewkey obj.visibility.track t
   k0.value = 0.0
   k0.inTangentType = k0.outTangentType = #step
   – unhide 15 frames later
   k1 = addnewkey obj.visibility.track (t+15f)
   k1.value = 1.0
   k1.inTangentType = k1.outTangentType = #step
   )
   )

thank you DenisT…
what does that mean?

k0.inTangentType = k0.outTangentType = #step

thank you man, I m learning many things tonight
I will dig the way you tell me…

if you want to get smooth transition from 0. to 1. (fade in) set #smooth type for OUT of key at time t and for IN and OUT for key (t+15f)