Boolean script question

but 3ds max does not make very clear chamfers, when the edges are not perpendicular to the chamfer line. Also you may need to reed the boolean's requirements in 3ds max reference. There are some restrictions. Also examine the proBoolean and proCuter objects, they are more powerful.

thanks

(
fn fnGetEdgesByVerts obj = (
 verts_array = polyop.getVertSelection obj
 edges = polyop.getEdgesUsingVert obj verts_array
 edges1 = copy edges
 For edge in edges1 Do (
  v = polyop.getVertsUsingEdge obj #{edge}
  For vert in v Do (
   If (findItem verts_array vert) == 0 Then (edges[edge] = false)
  )
 )
 return (edges) -- As bitArray
)

fn fnChamferByEdgeSelection obj /*chamfer_value*/ weld_threshold = (
 obj.weldThreshold = weld_threshold
 polyop.weldVertsByThreshold obj (polyop.getvertselection obj)
 polyop.setEdgeSelection obj (fnGetEdgesByVerts obj)
 select obj
 max modify mode
 subobjectlevel = 2
 --obj.edgeChamfer chamfer_value
 obj.popupDialog #chamfer
)

local obj_a, obj_b, result
 
rollout r "BooleanAdv" width:200 height:250 (

	pickbutton pick_objA "Pick Operand A" offset:[0,0]
	pickbutton pick_objB "Pick Operand B" offset:[0,0]
	on pick_objA picked obj do (
		obj_a = obj
		pick_objA.text = obj.name
	)
	on pick_objB picked obj do (
		obj_b = obj
		pick_objB.text = obj.name
	)
	radiobuttons rb labels:#("union", "subtraction a - b", "subtraction b - a", "intersection") offset:[0,0]
	spinner weld_threshold "Weld Threshold" offset:[0,0] range:[0,100,0.1] type:#float
	button boolean_btn "Create Boolean" offset:[0,0]
	button delete_btn "Delete the boolean" enabled:false offset:[0,0]
	on boolean_btn pressed do (
		result = undefined
		case r.rb.state of (
		(1):(result = (copy obj_a) + obj_b)
		(2):(result = (copy obj_a) - obj_b)
		(3):(result = (copy obj_b) - obj_a)
		(4):(result = (copy obj_a) * obj_b)
		default:(messageBox "Select the appropriate boolean's type.")
		)
		if result != undefined do (convertto result editable_poly; r.delete_btn.enabled = true;completeRedraw())
	)
	button chamfer_btn "Weld verts and Chamfer Borders" offset:[0,0]
	on chamfer_btn pressed do (
		fnChamferByEdgeSelection result (r.weld_threshold.value)
	)
	on delete_btn pressed do (try (delete result; r.delete_btn.enabled = false) catch ())
	label lab "BooleanAdv, 2016, Tsvetan St."
)
createDialog r
)

I've tried this, but the chamfer is still messy, especially when I try to make chamfer bigger..

fn fnChamferByEdgeSelection obj chamfer_value = (
 polyop.setEdgeSelection obj (fnGetEdgesByVerts obj)
 obj.edgeChamfer chamfer_value
)

rollout r "boolean" width:200 height:200 (
 spinner chamfer_val "Chamfer value" range:[0,19,1] type:#float
 button apply_btn "Apply"
 -- select the boolean and press the Apply button
 on apply_btn pressed do (
  undo "test" on (
   convertTo $ editable_poly
   fnChamferByEdgeSelection $ (r.chamfer_val.value)
  )
 )
)

You need to work with editable poly, so the script converts to.
I wrote this without testing it.
You can weld vertices, but what do you mean with mesh overlapping?

Did you saw Modo "Meshfusion" in action? You can see it on Youtube. The tool is producing clean dynamic booleans with the ability to change chamfer radius on the fly. The mesh is welding to the borders of chamfer, so there in no mess. In 3d Max, even if I catch the border of boolean and try to do big chamfer, the mesh becomes very messy and unclean. So, I'm searching a way to solve this problem in maxscript.

To get the edges by vertices:

fn fnGetEdgesByVerts obj = (
 verts_array = polyop.getVertSelection obj
 edges = polyop.getEdgesUsingVert obj verts_array
 edges1 = copy edges
 For edge in edges1 Do (
  v = polyop.getVertsUsingEdge obj #{edge}
  For vert in v Do (
   If (findItem verts_array vert) == 0 Then (edges[edge] = false)
  )
 )
 return (edges) -- As bitArray
)

Thanks, I will try this. Any thoughts about the second question?