Get list of vtx connected to a certain vtx

[busta]

Hi,

how can I get a list of vertices which are connected with an edge to a selected vertice?

[joojaa]

grow selected area and subtract the selected from the list with select border.

[macaronikazoo]

or more easily still, convert the selection to edges, and then back to verticies... you can do it with two lines of mel.

[strarup]

hi busta,

I hope this is not to confusing...

in this example I will use vertex 5, from a "new" generated polygonbox
//-----------------------------------------//
polyCube -w 1 -h 1 -d 1 -sx 1 -sy 1 -sz 1 -ax 0 1 0 -tx 1 -ch 1;
//-----------------------------------------//

to get the connected edges to the selected vertex you can use the polyInfo command... -->
polyInfo -ve; //Returns the Edges connected to a vertex. Requires vertices to be selected

I unfortunately can get a universal thingie to work, so I e.g. could use the selected object thingie (ls -sl), so that's why I have wrote the name of the object directly (pCube1.vtx[5])...

//-----------------------------------------//
	polyInfo -ve pCube1.vtx[5] ; //will give you the following result... -->
// Result: VERTEX      5:      9      2      7 
//-----------------------------------------//

now to get the connected vertices of the egdes...

//-----------------------------------------//
	polyInfo -ev pCube1.e[2];
// Result: EDGE      2:      4      5  Hard //
	polyInfo -ev pCube1.e[7];
// Result: EDGE      7:      3      5  Hard //
	polyInfo -ev pCube1.e[9];
// Result: EDGE      9:      5      7  Hard //
//-----------------------------------------//

edge 2 has vertex 4, edge 7 has vertex 3, and where edge 9 has vertex 7...
so in this particular case Vertex number 5, is connected to the vertices 3, 4 and 7...

unfortunately I don't know how the polyInfo command is build, so it could be a bit easier to extract info from it... but luckily Bryan Ewert has this example...
"How can a get a list of all vertex or edge components that are associated with a polymesh face? (or vice versa)"... -->
http://www.ewertb.com/maya/mel/mel\_a03.html

so I played a bit with it, maybe you can use it, and make a more generally script out of it...

//--------------------------------------------------------------------------------------------------------//
	int $i;
	string $edge[] = `polyListComponentConversion -toEdge pCube1.vtx[5]`; //edges to the selected vertex...


	for( $i = 0; $i < size ($edge); $i++ ) //to get vertices of the edges to the selected vertex...
	{
		string $verts[]=`polyListComponentConversion -toVertex $edge[$i]`; //the vertices which are "connected" to the selected vertex...
		print($verts);
		//print("// "+$edge[$i]+" //n"); //only for test purpose... prints the selected edge...
	};
//--------------------------------------------------------------------------------------------------------//

the printed result... -->
pCube1.vtx[4:5] //for edge number 2
pCube1.vtx[3]  //for edge number 7
pCube1.vtx[5]  //for edge number 7
pCube1.vtx[5]  //for edge number 9
pCube1.vtx[7]  //for edge number 9
//----------------------------

it is still teasing me a bit, and I'm not quite sure why it only make one line for edge 2, and a single for the other edges... problems still to solve is to get the selected vertex out of the result, and e.g. have the result on one line like...
// Vertex 5 is connected to vertex 3, 4 and 7....

I hope you can use it, and it isn't to messy...

regards

Strarup

[macaronikazoo]

now thats what i call a well researched post. nice work strarup!

BTW, as you can see from bryan ewerts page, the polyListComponentConversion is probably easier to deal with as it returns raw data, instead of informative text, like the polyInfo command does...

[busta]

Hey strarup, thx for your answer, helped me lot....

to get all vertices in the same manner, I insert the filter ... command at the end of the script. Only thing to do is to filter out the origin vtx, which should not that hard ...

int $i;
string $edge[] = polyListComponentConversion -toEdge pCube1.vtx[8]; //edges to the selected vertex...

for( $i = 0; $i < size ($edge); $i++ ) //to get vertices of the edges to the selected vertex...
{
string $verts[]=`polyListComponentConversion -toVertex $edge[$i]`; //the vertices which are "connected" to the selected vertex...
string $result[] = `filterExpand -ex true -sm 31 $verts`;

print($result);

[busta]

Hi Joojaa,

I tried this, but I think that this doesn't work for quads..

[strarup]

Hi macaroniKazoo,

thanks...

to Busta,

I'm glad I could help, I have also learn a lot trying to help solving it...

I have worked a bit more on the script, and it can now select more than one vertex, and spit out the output, I found some info regarding the command "stringArrayRemove", in the helpfile... -->
http://localhost:4444/Maya5.0/en\_US/Comman...ove.script.html

Example given in the help file...

string $list[] = { a, b, c, d, e, f, g };
string $items[] = { a, c, e, g };
string $diff[] = stringArrayRemove($items, $list);
// Result : { b, d, f } //

---

I have tested it, and if you put it in the script folder, and then type "getConnectedVertices" on the command line... it should write the result in the script editor...

I had some problems since string arrays don't like the "+" sign, and gives an error, but I solved it by making a seperate string, which got the extracted value from the current position from the array...

I also used the filterExpand command you wrote... to get them seperated, because if more than one vertex was selected, it would store it in the array as [a:z], instead of [a],[b]...[z]...
it also works if there are some edges selected aswell, however the test print "print($sVertex)" won't work if a edge also is selected along with the vertices...

I have put some "---" for seperation of the selected vertex and the connected result, since I haven't figured it out, how to get the result on one lline, e.g. like...

vertex nr. 1 is connected with: Vertex 2, Vertex 3, Vertex 4 etc.

instead of the result it gives at the moment...
--------------------------------------------------//
vertex nr. 1 is connected with:

---

Vertex 2
Vertex 3
Vertex 4
etc.
//--------------------------------------------------

but here it comes... hope you can use it...

regards

Strarup

///--------------------- start of script ------------------------------------------//
global proc getConnectedVertices()
{
int $j;
string $sVertexList[]=ls -sl; //the selected items/objects
string $sVertex[] = filterExpand -ex true -sm 31 $sVertexList; //"seperates" the arraylist, to get individual vertices...
//print($sVertex); //just for test purpose, to see if it works...

string $curVertex;

for( $j = 0; $j < size ($sVertex); $j++ ) //if there is more than one selected vertex...
{
	int $i; 
	string $edge[] = `polyListComponentConversion -toEdge $sVertex[$j]`; //edges to the selected vertex... 

	print("--------------------------------------------------// n");
	$curVertex = $sVertex[$j]; //current selected vertex...
	print($curVertex+" is connected with: n");
	print("  -------------------------------------------------- n");

		for( $i = 0; $i < size ($edge); $i++ ) //to get vertices of the edges to the selected vertex... 
		{ 
			//the vertices which are "connected" to the selected vertex... 
			  string $verts[]=`polyListComponentConversion -toVertex $edge[$i]`;
			  string $list[]  = `filterExpand -ex true -sm 31 $verts`; //connected vertex list...
			  string $items[] = {$curVertex};
			//remove the selected vertex from the connected vertex list...
			  string $result[] = stringArrayRemove($items, $list); 
			  print($result);
		}
	print("//-------------------------------------------------- n");

}

}
///--------------------- end of script ------------------------------------------//[/b]