[SOLVED] Node.rotate different ways lead to same result

Troubleshooting General Help
1

Hello,

I have a problem with rotation of geometries attached to nodes.
I’m getting the same result when I rotate an object in two different ways and I don’t understand why.
These two rotations are
Method 1) node.rotate((float)Math.toRadians(270),(float)Math.toRadians(0),(float)Math.toRadians(90));
Method 2) node.rotate((float)Math.toRadians(0),(float)Math.toRadians(270),(float)Math.toRadians(90));
I thought that the objects are rotated first around the X-axis, then the Y-axis and then the Z-axis.
This seems to be true for method one.
But if so the second method should lead to a different result. But the result is the same.
I’m really confused about this.

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2

Which version of the JME javadoc did you look at for the rotation ordering?

3

I don’t have a javadoc (please see my latest post)

4

If you think in terms of “extrinsic rotations” where the axes are unaffected by rotation, then the rotation order is x-z-y.

If you think in terms of “intrinsic rotations” where the axes rotate along with the object, then the rotation order is y-z’-x".

5

When in doubt:

image
image910×659 49.6 KB

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6

Has your confusion been cleared up?

7

Yes, it took some time to make some tests, but now I understand.
But now I have a new problem. I have to convert the angles that I get fom JME with the command node.getLocalRotation().toAngles(angles) to Angles in “my” System which rotates extrinsic in x,y,z order.
But my knowledge in mathematics is not good enough to calculate that. So I’m using a workaround at the moment. Luckily i’m only using 90° angles (so far) and I made a mapping table to get “my” rotation from the “jme” rotation. For Example 270:90:0 in jme is 0:90:90 in my rotation logic. But when I someday have to use “free” angles I will really be in trouble.

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