Assign random vertex color per element
Accepted solution
If random vertex color per element is enough (which may or may not result in duplicates, changing seed might help sometimes), you can use dataChannel modifier for that:
And as a script that ensures unique colors:
fn shuffle arr =
for counter = arr.count to 1 by -1 collect
(
local swapIndex = random 1 counter
swap arr[random 1 counter] arr[counter]
)
fn incrementCounters &r &g &b step =
if (b += step) > 256 do
(
b = 1
if (g += step) > 256 do
(
g = 1
if (r += step) > 256 do r = 1
)
)
fn getElements mesh =
(
local vertCount = mesh.numVerts
local faces = mesh.faces as bitArray
local facesByVert = for v = 1 to vertCount collect #()
for face in faces do
(
local faceVerts = getFace mesh face
append facesByVert[faceVerts[1]] face
append facesByVert[faceVerts[2]] face
append facesByVert[faceVerts[3]] face
)
for face in faces collect
(
local i = 0, element = #(face), elementVerts = #()
while (local f = element[i += 1]) != undefined do if faces[f] do
(
faces[f] = false
local faceVerts = getFace mesh f
for v = 1 to 3 do facesByVert[faceVerts[v]] =
for vertFace in facesByVert[faceVerts[v]] where faces[vertFace] collect
(
append element vertFace
append elementVerts (int faceVerts[v])
dontCollect
)
)
elementVerts as bitarray
)
)
fn assignUniqueElementColor obj op shuffleElements:off =
(
local elements = getElements (snapshotAsMesh obj)
local stepCount = elements.count^(double 1/3) + 1
local step = 255./stepCount
local redArr = shuffle (#(0) + #{1..255})
local greenArr = shuffle (#(0) + #{1..255})
local blueArr = shuffle (#(0) + #{1..255})
local r = 1, g = 1, b = 1
if shuffleElements do
elements = shuffle elements
for element in elements do
(
op.setVertColor obj 0 element [redArr[int r], greenArr[int g], blueArr[int b]]
incrementCounters &r &g &b step
)
)
if isKindOf $ Editable_Mesh then assignUniqueElementColor $ meshop shuffleElements:on
else if isKindOf $ Editable_Poly do assignUniqueElementColor $ polyop shuffleElements:on
If you instead want to bind it to a shortcut, you can save it as a .ms file and use the macroscript creator to make a macro for it.
Yes, it works with any editable mesh / editable poly that's currently selected and should work across most of the old max version, more than a decade back at the very least.
@Jixal wrote:
I have 9 objects that will be textured in Substance Painter and I want a random vertex color for each object (to use as an ID mask).
Something like
fn smootherStep x =
x * x * x * (x * (x * 6 - 15) + 10)
fn shuffle arr =
for counter = arr.count to 1 by -1 collect
(
local swapIndex = random 1 counter
swap arr[random 1 counter] arr[counter]
)
fn assignUniqueVertexColor objs shuffleItems:off seed:0 =
(
local maxVal = 256^3 - 1d0
local maxCount = objs.count
local counter = 0d0
if shuffleItems and ::seed seed == OK do
objs = shuffle objs
for obj in objs do
(
local clr = smootherStep (counter / maxCount) * maxVal
if isKindOf obj Editable_Poly do polyOp.setVertColor obj 0 #all [bit.shift (bit.and clr 0xff0000) -16, bit.shift (bit.and clr 0x00ff00) -8, bit.and clr 0x0000ff]
counter += 1
)
)
assignUniqueVertexColor (getCurrentSelection())
