How do I get the 2d rotation angle in radians of a Transform? | Bevy | Page 1

cold scarab Mar 17, 2024, 1:51 AM

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I've tried using transform.rotation.to_axis_angle() and transform.rotation.z, but neither returns radians.

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I've tried multiplying transform.rotation.z by PI but that also leads to weird values

amber patrol Mar 17, 2024, 1:59 AM

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to_axis_angle() claims to be in radians

cold scarab Mar 17, 2024, 2:07 AM

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amber patrol `to_axis_angle()` *claims* to be in radians

It is, but, for some reason it also inverts your angle when its between 180-360?

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so 181 becomes 179

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and 179 is still 179?

amber patrol Mar 17, 2024, 2:08 AM

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add tau/2?

cold scarab Mar 17, 2024, 2:09 AM

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no like

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hmm

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i think i miswrote

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180 = 0

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it returns the same for both 180 and 0

amber patrol Mar 17, 2024, 2:09 AM

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is the rotation axis inverted

cold scarab Mar 17, 2024, 2:11 AM

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amber patrol is the rotation axis inverted

I don't think so? both of these images return about 1.57 using to_axis_angle()

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despite facing opposite directions

amber patrol Mar 17, 2024, 2:12 AM

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(hypothesis) like in one case the axis is Vec3::Z and in the other it's Vec3::NEG_Z

cold scarab Mar 17, 2024, 2:13 AM

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I'll give it a test

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facing left side gives this

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facing right side gives this

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so yup!

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This works!

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but

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it feels like a really janky way just to get the angle lol

amber patrol Mar 17, 2024, 2:26 AM

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I think it's trying to find the axis which gives the mimum angle

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why it does that idk

cold scarab Mar 17, 2024, 2:37 AM

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yeah it's quite strange

#How do I get the 2d rotation angle in radians of a Transform?