(Need Help) Bone movement problem

redbol

Hello,

I can't figure out the spine-runtimes with the movement of the bone, for example, to the center of the screen. I tried to do it as written here: EsotericSoftware/spine-runtimes888 but the bone moves anywhere.

I work on a game engine: Corona SDK on lua

My code is here:

_H , _W = display.contentHeight, display.contentWidth;
function DragBone(options)
   local ID = tonumber(options.id)
   local Team = tostring(options.identy)
   local BoneName = tostring(options.bonename)
   

   local skeleton
   if Team == "hero" then
      for i=1, SlotGroupsHeroes.numChildren do
         if not SlotGroupsHeroes[i] then return false end
         if SlotGroupsHeroes[i].num == ID then
            skeleton = SlotGroupsHeroes[i]["skelbase"]
         end
      end
   elseif Team == "creep" then
      for i=1, SlotGroupsEnemy.numChildren  do
         if not SlotGroupsEnemy[i] then return false end
         if SlotGroupsEnemy[i].num == ID then
            skeleton = SlotGroupsEnemy[i]["skelbase"]
         end
      end
   end
   local FindBone = skeleton:findBone(BoneName)
   if not skeleton or not FindBone then return false end
   local DoSetPos = FindBone:worldToLocal({_W/2,_H/2})
   FindBone.x = DoSetPos[1]
   FindBone.y = DoSetPos[2]
end

PS, FindBone["parent"] gives nothing

Nate

You are trying to set a bone to a game world position?

First transform your game world position to the skeleton world space. The game position of your skeleton is 0,0 in the skeleton's world space, so:

worldX = gameX - skeleton.x
worldY = gameY - skeleton.y

If you don't position your skeleton in your game space then the skeleton's X and Y are zero and you can skip this step.

To position a bone, you need to set its local position. The local position of a bone is 0,0 in its parent bone's space, so get the parent bone, convert the skeleton world position to the parent bone's space, and then set the bone position. If your bone is the root bone it doesn't have a parent, in which case it is positioned in the skeleton's world space.

bone = skeleton:findBone("boneName")
if bone.parent == nil then
   bone.x = worldX
   bone.y = worldY
else
   parentPosition = bone.parent:worldToLocal({worldX, worldY})
   bone.x = parentPosition[1]
   bone.y = parentPosition[2]
end

redbol

Nate wrote
You are trying to set a bone to a game world position?

First transform your game world position to the skeleton world space. The game position of your skeleton is 0,0 in the skeleton's world space, so:
worldX = gameX - skeleton.x
worldY = gameY - skeleton.y
If you don't position your skeleton in your game space then the skeleton's X and Y are zero and you can skip this step.

To position a bone, you need to set its local position. The local position of a bone is 0,0 in its parent bone's space, so get the parent bone, convert the skeleton world position to the parent bone's space, and then set the bone position. If your bone is the root bone it doesn't have a parent, in which case it is positioned in the skeleton's world space.
bone = skeleton:findBone("boneName")
if bone.parent == nil then
   bone.x = worldX
   bone.y = worldY
else
   parentPosition = bone.parent:worldToLocal({worldX, worldY})
   bone.x = parentPosition[1]
   bone.y = parentPosition[2]
end

Thank you so much!
I added:
FindBone.x = FindBone.x-parentPosition [1]
FindBone.y = FindBone.y-parentPosition [2]

And its works! Thank you!

Nate

Great! 🙂 Thanks for following up.