Full Version: Help with Node Editor

Hi,

Reference the attached file.

I am trying to use Node Editor to allow rotating each of the two arms (orange and green) while keeping the green arm sensibly attached to the orange arm.

So far I have failed to obtain the desired behavior.

Rotating each arm is simple.

Moving the rotation point of the green arm to where it should be based on the rotation of the orange arm is where I am failing.

Thanks much.

Frederick

Attachments:
Support Arm.3dm

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you can't make group of group(s) ?

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Hi,

"group of groups"

I have no idea what that means.

Can you clarity?

Frederick

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Object A = Group 1
Object B = Group 2
Select Group 1, Group 2
Group 3 = Selected
When you rotate something there is inheritance...from arm to fingers! :) (theory)

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Hi Frederick,
The NodeEditor is not designed to do kinematics, but you can track the arm's rotation points via the "Select Filtered" node inside the Select menu. (Select/Select Filtered)

Pass the "Arm v01 Part 2 Shaft" (after rotation) into this node and set the mode to "Select Circle Edges", then use a "Bbox" node to determine its center point. (Objects/Bounding Box)

Here is the latest NodeEditor Plus version:
https://moi3d.com/forum/messages.php?webtag=MOI&msg=11614.1

Attachments:
ArmRotation_NE.nod

Image Attachments:
ArmRotation_NE.png 

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Hi MO,

Thanks for the feedback.

I'm going to have to study what you have done - it looks a bit complicated but it works a treat.

While waiting for feedback I asked Google AI about the issue and it came back with a solution using vector math that works, at least for simple lines, which is what I tested it with.

I don't know if that approach will work for the 3DM file I posted here, with the arms representing real world objects, as opposed to simple lines.

See attached.

Frederick

Attachments:
Rotate Two Lines V2.nod
Rotate Two Lines.3dm

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Hi,
Yes, I think the better solution would be to calculate the angles; my method was more of a workaround. You can still add points as rotation center points and use those instead of the cylinder objects.

Please check out the attached nod file.
I just found this node in my archives! I created it a while ago using points and vectors for three arms. It behaves more like a mechanism! You can add or remove arms easily by copying and pasting nodes and setting your desired pin joint points. Let me know if this is close to what you want.

Here is a tutorial that shows how to use the point picker node:
https://moi3d.com/forum/messages.php?webtag=MOI&msg=11887.1

Attachments:
Mechanism.nod

Image Attachments:
Mechanism.png 

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Hi MO

Thanks for the info.

I set out to apply the vector math approach to my actual objects and it works fine.

NodeEditor allows displaying the various vectors which is rather interesting to observe.

Frederick

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