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How to get the position of tf frame

asked 2023-05-03 07:20:48 -0600

TapleFlib gravatar image

How to get the position of the tf frame (child frame in rviz) , when I use tf.TransformListener().lookupTransform(parent_link, child_link, rospy.Time()) I get the relative position and relative orientation and not position and orientation, how to get the position and orientation using python script?

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answered 2023-05-03 11:42:37 -0600

tfoote gravatar image

All positions are measured relative to some reference frame. I believe that the rviz display is showing the position compared to your configured 'world' frame setting. And the position relative to the parent.

If you call lookupTransform(parent_link, child_link, Time(0)) You're explicitly asking for the transform between parent and child.

You wan to use lookupTransform(world_frame, child_link, TIme(0)) to get the latest transform from the world frame to the child link which I think is what you're considering non-relative position. You have to pick your reference to be able to do that.

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Got it thanks so much !

TapleFlib gravatar image TapleFlib  ( 2023-05-09 09:49:30 -0600 )edit

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Asked: 2023-05-03 07:20:48 -0600

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Last updated: May 03 '23