Grounding/ungrounding components - possible bug?

[lindsaywilson88]

Hi,

I've found something odd during the process of grounding and ungrounding components - I'm not sure if I'm misunderstanding or whether it's a bug. I'll try and explain - video link at bottom. Apologies in advance for the long-winded explanation!

New file, in this case "Test", and create a single, simple component in it, "Component1" (a cube). I then activate the parent "Test". As might be expected, I can move the component around. If I right-click the component and choose Ground, a ground action is added to the timeline, and a little pin symbol appears on the icon, and I can't move the component. If I now right-click the component again and choose Unground, an unground action is added to the timeline, and I can move the component again.

First question: why the separate ground and unground actions on the timeline? Why does the act of choosing "Unground" not just remove the previous grounding action?

Suppose I'm being perverse, and I now delete the ground action by clicking it on the timeline and hitting delete. I can still move the component around. However, if I now delete the unground action, thus restoring the timeline to its original state, a pin symbol appears on the component and it would appear to be grounded again! It's grounded, but with no actions to indicate it is.

(If I delete the unground action first, then the ground action, everything is fine).

Here's the video: https://www.youtube.com/watch?v=6sGOFc673Mo

I know that these actions are probably highly unlikely, but I don't understand why it behaves like it does.

Cheers,

Lindsay

[jeff_strater]

Hi @lindsaywilson88,

As to why "ground" and "unground" are timeline features, I'm not entirely sure.  I vaguely remember discussing this, but I can't remember a compelling reason.  I suspect it was just that all other assembly operations are timeline events, so why not ground/unground?  I'll ask around, to see if others can remember.

About your "perverse" workflow, that sounds like a bug.  I agree that if you have deleted the ground, and then delete the unground, the component should not still be grounded.  If you do a Modify->Compute all, you can see that the component is no longer grounded.  I will file this as a bug, and we'll take a look.  I agree that this is probably an uncommon workflow, but it is still worth investigating.

Jeff

[lindsaywilson88]

Hi @jeff_strater,

Many thanks for checking into this. I guess I'm still thinking on ground/unground as being like Solidworks' Fix/Float commands - they do the required
actions to the part/component, but don't add anything to feature tree. They act "outside" of the timeline.

I have a nagging feeling that having ground/unground as timeline features is actually very useful, but I still cant't think why!

Cheers,

Lindsay