Question [SOLVED] Misunderstanding v:del_animation(anim)

[johnnymanly]

I'm trying to use "del_animation" like this:

function clbk_poststep(simt,simdt,mjd)

if vi:get_groundcontact() == true then
    vi:del_animation(anim_Chute)
end

end

I'm expecting the animation to be deleted and the mesh groups to revert to their initial state but that's not what happens.
The animation is scaling. The chute scales up when it's supposed to but doesn't scale back down upon ground contact even though the animation is deleted.
From the docs:

Before the animation is deleted, the mesh groups associated with the animation are reset to their default (initial) positions.

Any help would be appreciated.

 

[Thunder Chicken]

Have you verified ground contact, and that the animation is in fact deleted?

What is the initial position for the animation? If it was initialized as fully inflated the code may be be behaving correctly.

 

[johnnymanly]

I verified ground contact with this:

if vi:get_groundcontact() == true then
  vi:set_animation(anim_Chute,0)
end

It works as expected.
I verified animation deletion by then calling del_animation at 300 meters. This stopped the previous code from working.
Initial position was "0", chute at small scale.

 

[Thunder Chicken]

Can you post the code where the animation is created?

 

[johnnymanly]

Relevant bits...

trans_Drogue = {                          -- transformation for drogue animation
  type = 'scaling',                       -- transformation type
  mesh = 0,                               -- mesh index
  grp = {1,2},                            -- group indices
  ref = {x=0,y=0,z=0.81},                 -- reference point
  scale = {x=100,y=100,z=100}             -- scaling amount
}

trans_Chute = {                           -- transformation for chute animation
  type = 'scaling',                       -- transformation type
  mesh = 0,                               -- mesh index
  grp = {7,8},                            -- group indices
  ref = {x=0,y=0,z=0.81},                 -- reference point
  scale = {x=100,y=100,z=100}             -- scaling amount
 
 
function clbk_setclasscaps(cfg)

  -- drogue chute animation
  animcomp_Drogue = oapi.create_animationcomponent(trans_Drogue)
  anim_Drogue = vi:create_animation(0)
  vi:add_animationcomponent(anim_Drogue,0,1,animcomp_Drogue)

  -- chute animation
  animcomp_Chute = oapi.create_animationcomponent(trans_Chute)
  anim_Chute = vi:create_animation(0)
  vi:add_animationcomponent(anim_Chute,0,1,animcomp_Chute)
 
end

 

[Thunder Chicken]

Can you set the animation state to zero manually before deleting the animation?

It may be that there is something in the Lua version of the delete function that differs from the C++ API version, even though the documentation is the same.

 

[johnnymanly]

I was hoping it was simply my fault but I'll just have to work with it.
Thanks for looking.

 

[Thunder Chicken]

I was hoping it was simply my fault but I'll just have to work with it.
Thanks for looking.

Might want to post a bug issue on the OpenOrbiter GitHub.

 

[johnnymanly]

Easy workaround is to clear the meshes, which deletes the animations, then add the mesh again.

if vi:get_groundcontact() == true and vi:get_attachmentstatus(Attach0) == nil and vi:get_attachmentstatus(Attach1) == nil then
  vi:clear_meshes()
  vi:add_mesh('JMpl/JMpl')
end

 

[Thunder Chicken]

It might be a bit more efficient to just set the animation state to zero before deleting the animation:

if vi:get_groundcontact() == true then
    vi:set_animation(anim_Chute,0)
    vi:del_animation(anim_Chute)
end

 

[johnnymanly]

It might be a bit more efficient to just set the animation state to zero before deleting the animation:

if vi:get_groundcontact() == true then
    vi:set_animation(anim_Chute,0)
    vi:del_animation(anim_Chute)
end

One would think so but it doesn't work.

 

[Thunder Chicken]

One would think so but it doesn't work.

That's odd. You can set the animation state to zero, you can delete it, but you can't do them together in the same loop?

If you have a prestep callback, you might try putting that loop in that and see if you get different behavior.

 

[johnnymanly]

Well actually, it works with both statements in the prestep. I should've checked that.
Thanks for the help. It looks good so far.

 

[johnnymanly]

Final configuration:

function clbk_prestep(simt,simdt,mjd)

  if vi:get_groundcontact() == true and vi:get_attachmentstatus(Attach0) == nil and vi:get_attachmentstatus(Attach1) == nil then
    vi:del_animation(anim_Chute)
  end

end

function clbk_poststep(simt,simdt,mjd)

  if vi:get_groundcontact() == true then
    vi:set_animation(anim_Chute,0)
  end

end

del_animation must be in prestep with set_animation in poststep.

 

[Thunder Chicken]

Final configuration:

function clbk_prestep(simt,simdt,mjd)

  if vi:get_groundcontact() == true and vi:get_attachmentstatus(Attach0) == nil and vi:get_attachmentstatus(Attach1) == nil then
    vi:del_animation(anim_Chute)
  end

end

function clbk_poststep(simt,simdt,mjd)

  if vi:get_groundcontact() == true then
    vi:set_animation(anim_Chute,0)
  end

end

del_animation must be in prestep with set_animation in poststep.

Is set_animation still required? Did you check to see if del_animation does the advertised behavior if it is in the prestep callback?

 

[johnnymanly]

I just checked. It does not.