What does RootNode refer to in MotionTarget.getSimWorldToRootNode()

Python Programming
1

Hello everyone

I have a linear axis robot and would like to calculate the flange’s reference position (position where all joints have a value of zero).

For that I make use of the MotionTarget class, since it has some useful functions to calculate certain positions.

I tried it this way:

target = robotController.createTarget()

jointValues = [0.0] * len(target.JointValues)
target.JointValues = jointValues

flangePos = target.getSimWorldToRootNode()
flangePos *= target.getRobotRootToRobotFlange()

But when I do so, the position in “flangePos” is not correct.

By further investigating this, I realized that the method “getSimWorldToRootNode()” always gives me the same position even when I move the component’s origin.

So my question is what exactly does “RootNode” refer to in this method?

Thanks for any help!

2

This is the description of getSimWorldToRootNode() on the help document: Returns the offset from 3D world origin to root node. Tested and it seems to do the work. See image below.

3

Hi Jay

 

Thanks for your answer!

I know right? It should actually return the position of the component in world coordinate system but it doesn’t in my simulation.

As I mentioned I think this happens because I moved the component’s origin.

Because when I move the origin the rootPos stays the same, it only changes when I move the component as a whole (including geometry).

Is this maybe a bug or do I get something wrong?

What happens on your side when you move the robots origin?

 

I appreciate your support!

Johnny

 

PS: The version I use is Visual Components 4.1 Professional