How do I build Unconnected Edges Selections from EPoly Edge Selection?

MAXScript Frequently Asked Questions

A user asked:

I want to filter the edge selection and create arrays containing connected edges, something like "edge selection elements". Edges from two arrays will never be connected, in other words will not share vertices.


The following pseudo-code describes a possible approach:


The function is ready when there are no edges left in the main array.

This will give you as many sub-arrays are there are unconnected edge selections.


The following function implements the pseudo-code in MAXScript code:


fn getEPolyUnconnectedEdgesSelections thePoly =


--get the edge selection

mainSelection = (polyOp.getEdgeSelection thePoly) as array

--init. an array to collect sub-arrays with selections "elements"

unconnectedSelections = #()

--repeat until the main selection array is empty

while mainSelection.count > 0 do


--append a new empty sub-array:

append unconnectedSelections #()

--remember the current sub-array's index

currentSelCount = unconnectedSelections.count

--append the first edge from the main selection array to the sub-array

append unconnectedSelections[currentSelCount] mainSelection[1]

--and remove the first edge from the main selection array

deleteItem mainSelection 1

--init. a counter

cnt = 0

--while the counter is less than the edges in the sub-array

while cnt < unconnectedSelections[currentSelCount].count do


cnt += 1 --increase the counter by 1

--get the vertices of the current edge in the current sub-array

currentEdgeVerts = (polyOp.GetVertsUsingEdge thePoly unconnectedSelections[currentSelCount][cnt]) as array

neigborEdges = #() --init. an array to collect neighbor

--gor every vertex in the current edge,

for v in currentEdgeVerts do

--add the edges used by the vertex to the neighbors array

join neigborEdges ((polyOp.GetEdgesUsingVert thePoly v) as array)

--for each neighbor edge,

for edge in neigborEdges do


--see if the edge is in the main selection array

checkInSelection = findItem mainSelection edge

--if it is,

if checkInSelection > 0 then


--delete the edge from the main array

deleteItem mainSelection checkInSelection

--and add it to the current sub-array

append unconnectedSelections[currentSelCount] edge

)--end if

)--end for edge loop

)--end while cnt

)--end while mainSelection.count

--finally, return the array containing the sub-arrays of connected edges:


)--end fn


getEPolyUnconnectedEdgesSelections $Box01 --call the function


See also

Frequently Asked Questions