MAXScript Frequently Asked Questions
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:
Get the current edge selection into a main selection array.
Create an empty array to hold the unconnected selections
(A) Append a new empty array to it as a sub-array.
Note the index of the current sub-array.
Get the first edge from the main selection array.
Delete it from the main selection array, append to the current sub-array of the unconnected selections array.
For every edge in the new sub-array,
Get its corresponding vertices that define the edge
For each of the two vertices, get their edges - this gives you all neighbor edges sharing a vertex with the current edge
Loop through the neighbors and see if they appear in the main selection array.
If an edge is in the main selection array, delete it from there and append it to the current sub-array.
Finish the loop when you have checked all edges from the sub-array.
At this point, if all edges were connected, the main array will be empty. If it is not empty, there are edges unconnected to the selections you already collected.
Add a new empty sub-array to the collection array
Repeat starting with (A)
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
--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 for edge loop
)--end while cnt
)--end while mainSelection.count
--finally, return the array containing the sub-arrays of connected edges:
getEPolyUnconnectedEdgesSelections $Box01 --call the function
Frequently Asked Questions