What's with parenting tracking objects?

Without parenting involved, my arrow points to the target as planned. But when I parent the arrow to a moving object, things go wrong. I’m not sure, but I think that as the parent rotates, the child must rotate and therefore changes what part of it is doing the tracking. This happens in both the animator and the game engine. Help?

you are having the child of some object track something?

uhh… that sounds kind of sketchy… yeah, I see what you mean, it does act weird… it seems to overcompensate for the rotation

which makes sense considering what happens if you rotate the tracking object…

if it is a vertex parent instead it works they way you want [you may have to rotate it differently, but it will not spin weird when you turned like before]

I just tried a quick test and if you use Ctrl-T>Old Track the problem you describe is true. However, if you choose “Lock Track Constraint” it seems to perform as you’d expect.

Beyond that, I don’t know much about it :slight_smile:

I tried what zer0d suggested with the vertex parenting. It works, but only if the vertex is near the middle of the object. At least it works at all. The other method worked but couldn’t be used in the game engine, which is what I need as of right now.

I don’t know a thing about the game engine, but does copy location work? If so, can you use this instead of parenting, that way the camera follows the “parent” object but doesn’t copy rotation.

No, I’m quite sure that constraints applied from the F7 window don’t work in the game engine.

in edit mode you can select a vert, and control+rmb select the object to do a vertex parent to a particular vert

vertex parents work in the game engine

you can make that vert in the center of your object

… now, I haven’t tested tracking in the game engine so I wouldn’t know if that works the same, but I see no reason why it wouldn’t.

This is kind of related to this, you know the purple dots that are supposed to be in the center of each object? How do you move them to the center of the objects if they are located far away from the objectt, without have the object move?

You mean “to the center of the Mesh?”, in Edit Mode, Mesh tab, Center New.