Displacement Issue

One of our engineers working with FlexSim encountered the following issue. I will copy/paste his description of the issue:

To the left there are four .3ds cylinders (the default shape), all with the same
coordinates (-15, 0, 0), but with different y-scaling. No rotation.

To the right are four cylinders, also all with same coordinates (1, 1, 1) but different y-scaling.
These cylinders are rotated 90 degrees around the z-axis.

So the only difference between left and right is the rotation. The objects to the left all have
a side positioned at the specified coordinate. The objects to the right lie far from
the specified coordinate.

I think this behavior is due to adjusting the center of the object after scaling, and that
this adjustment is in the wrong direction when the object is rotated.

The question we have for FlexSim developers is: Is this by design or is this a bug? We encountered this while trying to export coordinate data (x,y,z; rotations etc) to another 3D tool and reconstruct the objects.

The object's location is the position at the upper-left corner of an object at {0,0,0} rotation (given that you are looking at it from a reset view).

This object has a centroid attribute of 1 (Shape>spatial/centroid), which means that the object's rotation is based around the center of its size rather than its position.

If you change the centroid attribute to 0, then it will behave as you expect with the rotation based around the object's position instead of the object's midpoint.

Because of the centroid attribute of 1, the object's position might not be touching the yellow box because you can rotate the yellow box around a point other than the object's position.

This is by design. You need to account for an object's centroid attribute in your export to get the position and rotation of the object correct.