Child object doesn't stay relative to parent in BGE

Question

I'm making (another) plane game but the propeller, which is parented to the plane, keeps moving weirdly.
Here is an image of the whole plane, before I go into the game: 3dview

Then, when I go into the game, it looks like this:

Which is OK, so far. But now, when I move the mouse to rotate the plane, the propeller detaches from the plane:

Is there a way to keep the propeller attached in the same position on the plane?

If it helps, here is the blend file.

@Chebhou This doesn't seem to work - can you explain it further? — Jacob_, Jul 19 '15 at 19:08

score 3 · Accepted Answer · edited Apr 13 '17 at 12:57

3

This was a simple case of unapplied scale and rotation. The odd thing is blender handles parents with different transforms just fine, but the game engine does not.
As a general rule everything in the BGE should have a scale of one, and no rotation.

All I did is apply the scale and rotation on both the plane and the propeller, then the normal object parent worked as expected in the BGE.

Here is your fixed blend with parent working, plus you had the normals on your plane reversed.

If you haven't seen my explanation on the parenting settings, go read it here.

edited Apr 13 '17 at 12:57

Community

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answered Jul 19 '15 at 21:53

David

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How do you "apply the scale and rotation"? @David – Jacob_ Jul 20 '15 at 17:58
@Jacob_ http://blender.stackexchange.com/a/6445/2217 – David Jul 20 '15 at 18:10
actually never mind, I managed :) – Jacob_ Jul 20 '15 at 18:16

score 1 · Answer 2 · edited Sep 02 '17 at 17:45

1

Select two objects, press Ctrl + A and choose Rotation & Scale to apply it to object data.

edited Sep 02 '17 at 17:45

Mr Zak

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answered Sep 02 '17 at 16:24

ZombieInfected_Project

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Child object doesn't stay relative to parent in BGE

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