How do I remove mid-edge EPoly Vertices?

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 code implements a possible solution:



macroScript KillMidEdgeVerts category:"MXS Help"


--make sure a single EPoly object is selected

on isEnabled return selection.count == 1 and classof selection[1].baseobject == Editable_Poly

on execute do


thePoly = selection[1] --get the selected object

select thePoly --select it

max modify mode --switch to modify panel

--set the base object as current level:

modPanel.setCurrentObject selection[1].baseobject

subObjectLevel = 1 --set sub-*object level to vertex level

numVerts = (polyop.getNumVerts thePoly) --get the total vertex count

undo on "KillMidEdgeVerts" --enable undo context


--loop backwards from the last to the first vertex

for v = numVerts to 1 by -1 do


--get the edges using the vertex to check the count

nVerts = (polyop.getEdgesUsingVert thePoly v) as array

if nVerts.count == 2 do --if only two edges found, then


--get the verts of the first egde

edge1verts = (polyop.getVertsUsingEdge thePoly nVerts[1]) as array

--calculate the vector defined by the two vertices in the first edge

vector1 = (polyop.getVert thePoly edge1verts[1]) - (polyop.getVert thePoly edge1verts[2])

--get the verts of the second edge

edge2verts = (polyop.getVertsUsingEdge thePoly nVerts[2] as array)

--calculate the vector defined by the two vertices in the second edge

vector2 = (polyop.getVert thePoly edge2verts[1]) - (polyop.getVert thePoly edge2verts[2])

--calculate the angle between the two normalized vectors

angle = acos (dot (normalize vector1) (normalize vector2))

--if the angle is less than the threashold (change 0.01 to whatever threashold you want!)

if angle < 0.01 do


select thePoly.verts[v] --then select the current vertex

thePoly.EditablePoly.buttonOp #Remove --and hit the remove button


)--end if

)--end v loop

)--end undo

)--end on

)--end macro


See also

Frequently Asked Questions