[Closed] Unifying Spline Direction

Hello, I’m a newbie in MAXScript

I need some help with my current situation: I want to generate spline from selected edges of Editable Poly object. Heres what I did:

SCENARIO 1

1. Select the edges I wanted to convert to spline
2. Use polyOp.getEdgeSelection to get the selected edges
3. Use polyOp.createShape to create spline

The above codes does exactly the same as when we click button “Create Shape From Selection” from EPoly rollout panel

…and the result is:

The problem is that there’s always 1 spline that has reversed direction compared to the others (notice the yellow point that represents the index 1 of each spline knot). Also the spline number is also in un-orderly fashion (5-4-3-1-2) instead of (5-4-3-2-1)

This can be simply fixed manually by selecting the reversed spline and and click the Reverse Button or use reverse <spline> in MAXScript. However I have trouble in finding the algorithm to detect which spline is reversed from the others.

After some digging, I then create another scenario. Instead of using EPoly, I used EMesh.

SCENARIO 2

1. Select the edges I wanted to convert to spline (still in EPoly)
2. Convert to / add modifier EMesh (found it preserves the selected edges, yay)
3. Click “Create Shape From Edges” button in the EMesh rollout panel

Here’s the result when I did it manually:

It fixed the spline and the knots order. However when I used meshOps.createShapeFromEdges in MAXScript which supposed to do the same as above, I got error.

Here’s my code:

obj = selection
convertToMesh obj
meshOps.createShapeFromEdges obj

Here’s the error:

-- Error occurred in anonymous codeblock; filename: MY_MAXSCRIPT_FILE_URL; position: 68; line: 3
-- Known system exception
-- ########################################################################
-- Address: 0x116fbc8; nCode: 0x00000000C0000005
-- Desc: EXCEPTION_ACCESS_VIOLATION The thread tried to read from or write to a virtual address for which it does not have the appropriate access.
--       Write of Address: 0x000000000116FBC8
-- ########################################################################
-- MAXScript callstack:
--	thread data: threadID:4792
--	------------------------------------------------------
--	[stack level: 0]
--	In top-level
-- ########################################################################
-- C++ callstack:
-- (MAXScrpt): (filename not available): UndoBaseObject::`vftable'
-- (MAXScrpt): (filename not available): MeshValue::intern
-- (MAXScrpt): (filename not available): MeshValue::intern
-- (MAXScrpt): (filename not available): Primitive::apply
-- (MAXScrpt): (filename not available): StructDef::apply
-- (MAXScrpt): (filename not available): CodeTree::eval
-- (MAXScrpt): (filename not available): SourceFileWrapper::eval
-- (MAXScrpt): (filename not available): Listener::set_style
-- (USER32): (filename not available): EnableSessionForMMCSS
-- (USER32): (filename not available): EnableSessionForMMCSS
-- (USER32): (filename not available): EnableSessionForMMCSS
-- (USER32): (filename not available): DispatchMessageW
-- (USER32): (filename not available): CallWindowProcW
-- (UIControls): (filename not available): InitializeCustomUI
-- (UIControls): (filename not available): (function-name not available)
-- (USER32): (filename not available): DispatchMessageW
-- (USER32): (filename not available): DispatchMessageW
-- (USER32): (filename not available): CreateMenu
-- (3dsmax): (filename not available): XMLAnimTreeEntry::GetUnique
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- (VCRUNTIME140): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- (clr): (filename not available): LegacyNGenTryEnumerateFusionCache
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- (3dsmax): (filename not available): UtilGfx::kFONT_WIDTH
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- ((module-name not available)): (filename not available): (function-name not available)
-- ########################################################################

Also I heard that meshOps.createShapeFromEdges will show a dialog which I do not want. I prefer to do it silently like polyOp.createShape does.

I’m opened to any suggestion or workaround for this problem.
Thanks in advance!