How to display vector field after vertices' displacement?

[Anonymous]

Hi all,

I am wondering if this thing is actually possible in 3ds max. Basically, I have two editable meshes representing the same object at two different times. They are exactly the same (same number of points etc.), just in different configurations. I am studying the transition from time 1 to time 2. I applied the Morpher modifier to represent the motion between the two states. What I am interested in is to display the vectors that represent the displacement of each single vertex of the mesh between the initial and the final state. Basically I am looking for a way to connect corresponding vertices with a segment. I know this concept as 'vector field', representing the motion of a set of points in time. I know that 3ds max features a 'vector field space warp' object but that is NOT what I am looking for. Do you know if it's doable/any possible solutions to this problem? Thanks a lot!!

[leeminardi · Accepted solution]

Here's a Maxscript that will draw lines between corresponding vertices of two selected objects.  Is this something like what you want?

-- Creates lines between corresponding vertices of two selected editable meshes.
-- No error checking is done.
-- v1  12/30/2020  LRM
--
objA = selection[1]
objB = selection[2]
nV = meshop.getNumVerts objA
nvt = nv as string
rollout vectorRollout3 "Morph Vectors" width:200 height:160
(
	button 'btnGo' "Go" pos:[32,104] width:96 height:36 align:#left
	edittext 'edt1' "" pos:[64,32] width:78 height:24 align:#left
	label 'lbl1' "Start vertex" pos:[0,32] width:65 height:15 align:#left
	edittext 'edt2' "" pos:[64,64] width:78 height:24 align:#left
	label 'lbl2' "End Vertex" pos:[0,64] width:56 height:16 align:#left
	label 'lbl3' "Total number of vertices:" pos:[0,8] width:120 height:17 align:#left
	label 'labelnverts' nvt pos:[128,8] width:48 height:19 align:#left
	on btnGo pressed do
	(
		vstart = edt1.text as integer
		vend = edt2.text as integer
	   morph_vectors vstart vend
		messagebox "Done"
	)
)
createdialog vectorRollout3 

fn morph_vectors vstart vend =
(	
-- Creates a line between corresponding vertices of two selected objects 
-- that have the same number of vertices.
--
for i = vstart to vend do
(	
pA = meshop.getVert objA i
pB = meshop.getVert objB i 
newLine = Line2Points pA pB
)

fn Line2Points pointA pointB =
(
  ss = SplineShape pos:pointA
  addNewSpline ss
  addKnot ss 1 #corner #line PointA
  addKnot ss 1 #corner #line PointB
  updateShape ss
  ss
)
)

[Anonymous]

@leeminardi  Thank you very much!! This is surely a very helpful starting point! Do you have any ideas about how to make it more dynamic? I mean like automatically adapting the lines when I move one of the two meshes to always keep them connected? I am thinking about displaying somehow the changes in the lines' lengths during an animation (while using the morpher modifier would be perfect, but probably not doable?). Thank you again!

[leeminardi]

I am not skilled enough with Maxscripts to make the vectors dynamic.  I suggest you post the question on the 3ds Max Programming forum.