[BUG] Child objects shift position is parent is scaled and rotated

Game Engine Game Engine Support and Discussion
1

Just wanted to confirm this before I submit a bug report.

It looks like if a parent object is rotated on one axis and scaled unequally on the other two axes, the object’s children’s positions will shift when the game engine starts.

For example, an object rotated on the x-axis and scaled by [1, 2, 1] will exhibit the problem while and object rotated on the same axis but scaled by [2, 1, 1] or [1, 2, 2] will not.

Here’s a blend that demonstrates the issue. Just start the game engine and note how 3 of the 4 cubes shift positions.

scale_shift_bug.blend (81.1 KB)

EDIT: Looks like this bug has been around for awhile: https://developer.blender.org/T33512
Hopefully it’ll get fixed soon.

2

Not really a game engine guy… but in a normal animation context one would apply scale and rotation to the empties to prepare them for animation. Doing so with your Blend removed the “jump” when entering the game engine.

3

The report is from 2013.

I suggest to add yourself to the bug. This will not help to fix it, but show that it is not a rare situation.

Edit: I see you already did, :slight_smile:

4

what about for a work around, add the pieces after frame 0, and move them to a local position and then parent them to the object in game?