topic Re: Delete a mesh Point in Modeling

Delete a mesh Point

gotphish001 — Mon, 07 Nov 2022 17:09:30 GMT

The only posts I've found are from decades ago.

Yes, I can drag a single mesh node outside of the boundary and it disappears, but only if the node is connected to nothing. Yes, you can delete an entire contour line ridges. Yes, you can make a hole in the mesh around points to delete them, but then you need to redraw what you cut out and fix points that got changed that didn't need changed.

How do I delete a point that is on the edge of the mesh or one node out of a contour line? It just stacks points up at different elevations if I just move it on top of another point. Can we not do this? Meshes get crazy complex even worse so by not being about to remove points. Seems like a very simple thing to add.

Re: Delete a mesh Point

Anonymous — Mon, 07 Nov 2022 22:59:23 GMT

You don't have to move single node out of the mesh, with only that one node selected hit delete and it will be removed.

This doesn't work on boundary though. I'd always just drag the point on top of another one and that will always merge them.

But you do raise an interesting point (couldn't resist 😄 ), there is no function for removing nodes. GS, perhaps add X button to the pet palette?

Re: Delete a mesh Point

gotphish001 — Tue, 08 Nov 2022 16:28:02 GMT

That is incorrect. Moving a node onto another node that is on a boundary or a contour line does not merge them. It makes two nodes on top of each other that can have different elevations. My question still stands. There's no way to delete a node on a boundary or contour line.

Re: Delete a mesh Point

Barry Kelly — Wed, 09 Nov 2022 01:59:44 GMT

@gotphish001 wrote:

That is incorrect. Moving a node onto another node that is on a boundary or a contour line does not merge them. It makes two nodes on top of each other that can have different elevations. My question still stands. There's no way to delete a node on a boundary or contour line.

Are you sure?

Meshes can not have nodes vertically above each other.

You must have a slight displacement in plan.

I just tried in plan and 3D and the nodes merge to one.

But having said that, I just played around adding a new ridge and then deleting those nodes.

Something I did in the process (I am not sure what) has now made it so that the mesh creates a new node when some of the edge nodes are moved.

Not for all nodes but just for some.

The original node will not move, but duplicates.

So there is something strange going on, but I don't know what exactly.

That duplicate node can be moved and does not duplicate again, and if moved over another node it merges.

If I move another node over the one that can not be moved, they do not merge, which is I think what you are experiencing.

Separate the nodes again in plan.

You should find one will move, the other won't, it will just duplicate.

I just tried to repeat this on a new mesh, and I can't.

Something in the editing of ridges and nodes seems to be corrupting some of the edge nodes.

Barry.

Re: Delete a mesh Point

gotphish001 — Wed, 09 Nov 2022 15:00:44 GMT

I do have some nodes that I can't seem to move on the edge of the mesh. I 100% have points directly on top of each other that are different elevation. Unless when I'm snapping one to the other it doesn't put it exactly on top, but that seems like weird functionality.

Edit: I went in the project. It functioned like you mentioned, nodes merge. But then I found one that had 5 points all on top of each other. I was trying to merge them yesterday or whenever I asked this question originally. I could pull them all off, move them around, put them all back on top of each other again in a new spot and then pull them all off again. I can't seem to find any of the nodes that I said I couldn't move, so I'm not 100% on if that is the case.

Re: Delete a mesh Point

gotphish001 — Wed, 09 Nov 2022 15:09:02 GMT

Ok, I found a node that I can't move. When I try and move it, it just makes more nodes and doesn't move. I pull like 25 nodes off the stuck node before I gave up. All the nodes that I can't seem to merge are these extra nodes created from trying to move the one stuck node. It's probable that I have more stuck nodes like this and this is why I thought you can't delete nodes.

Re: Delete a mesh Point

Anonymous — Thu, 10 Nov 2022 00:14:11 GMT

@Barry Kelly, is there a way to export coordinates of all mesh points as xyz?

If this is not a too big of a mesh, you can place a 3D coordinate object on each node and schedule out their coordinates. You could review them in a spreadsheet and then import back to Archicad as "place mesh from surveyors data".

Re: Delete a mesh Point

gotphish001 — Thu, 10 Nov 2022 15:17:24 GMT

I'll need to check those issue nodes coordinates. I'll turn up the precision to see if they are off by some amount I'm not seeing.

Re: Delete a mesh Point

Anonymous — Fri, 11 Nov 2022 01:18:08 GMT

Actually you can get coordinates if you save the mesh as an object. Didn't think of this before.

It would require looking into the gdl code to get them though.

1. Select the mesh and go to File -> Libraries and Objects -> Save selection as -> Object

2. Ok on the Attributes window and any other popup.

3. Select object tool and place the newly created object

4. Select the object

5. File -> Libraries and Objects -> Open object

6. Go to Scripts section on the left navigation and open "3D"

7. Mesh should be converted into "mass". In my case it was "mass{2}"

Skip the next line under the mass as those are still mass command parameters

Coordinates of the top of your mesh should start from the next line in the format

x, y, z, status code

Coordinates with -1 status code I believe are the non boundary points of the mesh.

I am on windows so I would grab them and paste to notepad and save as csv or text. You can then open this in excel as comma separated values.

I would add a numbered index as an additional column in the spreadsheet if you are going to be sorting them so you can revert to original sorting order.

Re: Delete a mesh Point

Barry Kelly — Fri, 11 Nov 2022 02:25:37 GMT

I don't think there is any problem with the precision.

Something is happening to some of the edge nodes.

Exactly what that is I am not sure.

But it seems a node is created that doesn't move but duplicates.

These nodes can be stacked on top of each other, which should not be possible.

It seems to me that some of these edge nodes are actually internal ridge node.

They can be moved over an edge node and both nodes still exist, they don't merge.

That is it.

I just created an internal ridge.

If I now move one of tho ridge nodes to the edge, it becomes an edge node but it is still a ridge node (if that makes any sense).

I can now elevate that node.

I can't move the node, it will just duplicate.

That copied node can be moved over any other node.

In this case it just becomes a 'free' node in 3D, but I have seen it drag the surface with it.

This is now 2 nodes stacked on top of each other, move one and the other will still be there.

And if I drag it further along, the original edge node is still there.

So actual edge nodes can't be stacked over other edge nodes - they will merge.

Ridge nodes can't be stacked over ridge nodes - they will merge.

But is seems you can move a ridge node to the edge, it will take control or the edge of the mess, but is not an edge node as such and will not merge with other edge nodes.

Barry.

Re: Delete a mesh Point

Barry Kelly — Fri, 11 Nov 2022 02:33:02 GMT

If you save the mesh as a library object, it will create a MASS in the 3D script.

This mass has all of the X, Y, Z co-ordinates.

But I think you will have a hard time trying to find the nodes that are sitting on top of each other (same X & Y but with different Z).

Barry.

Re: Delete a mesh Point

Barry Kelly — Fri, 11 Nov 2022 02:35:55 GMT

Snap!.

I started to reply before seeing your reply, but got delayed and didn't submit till after you.

Barry.

Re: Delete a mesh Point

gotphish001 — Fri, 11 Nov 2022 14:33:12 GMT

You seemed to have nailed down the issue. I'll have to try a few tests and see what exactly reproduces it. I drew my initial splines that I magic wanded to make my contours all the way to the edge of the mesh. I'll have to do a test, but I'm thinking that is causing it. If I'm remembering correctly, you can't add a contour line directly into the mesh with it starting (I don't think ending point matters, but it might for this glitch) on the edge of the mesh. You need to start it from a point not on the edge. Since I magic wanded splines that started on the edge, I'm assuming this is what caused these glitched points. You can't directly draw the contour like that, but the magic wand let me do it even though it is not supposed to work. I drew all the splines starting on the north side of the mesh, so it should be clear which points are the starting and ending ones. I'm uncertain if the magic wand takes that into account when making the contours from the spline. If it does then only my end points on the south side of my mesh should be the messed up nodes.