Vertex colors for lines and tubes in 13.0 vs 13.1

Questions
1

In version 13.0 there were some issues with vertex colors for tubes which has been fixed in 13.1.

However now specifying multiple lines within one Graphics Primitive The vertex colors are only applied the first object. The workaround is easy by just defining individual Graphics Primitives, but i don’t think this is the intended behavior.

Version 13.0

v13.0.png
v13.0.png809×1009 246 KB

Version 13.1

v13.1.png
v13.1.png878×1095 187 KB

dat = {Table[{Cos[x], Sin[x], x/10}, {x, 0., 10}], 
   Table[{Cos[x], Sin[x], x/10 + 2}, {x, 0., 10}]};
col = Map[RGBColor, dat, {2}];
pl = {
  Graphics3D[{PointSize[Large], 
    Point[Flatten[dat, 1], VertexColors -> Flatten@col], Line[dat]}],
  Graphics3D[{Thick, Line[dat, VertexColors -> col]}],
  Graphics3D[{CapForm["Square"], JoinForm["Miter"], 
    Tube[dat, VertexColors -> col]}, Lighting -> "Neutral"]
  }


dat = RandomReal[1, {150, 7, 3}];
col = Map[RGBColor, dat, {2}];
pl = {
  Graphics3D[{PointSize[Large], 
    Point[Flatten[dat, 1], VertexColors -> Flatten@col], Line[dat]}],
  Graphics3D[{Thick, Line[dat, VertexColors -> col]}],
  Graphics3D[{CapForm["Square"], JoinForm["Miter"], 
    Tube[dat, VertexColors -> col]}, Lighting -> "Neutral"]
  }
pl2 = {
  Graphics3D[{PointSize[Large], 
    Point[Flatten[dat, 1], VertexColors -> Flatten@col], Line[dat]}],
  Graphics3D[{Thick, 
    MapThread[Line[#1, VertexColors -> #2] &, {dat, col}]}],
  Graphics3D[{CapForm["Square"], JoinForm["Miter"], 
    MapThread[Tube[#1, VertexColors -> #2] &, {dat, col}]}, 
   Lighting -> "Neutral"]
  }
2

This is an unexpected behavior. The bug has been filed and will be fixed in the next version.

3

It has indeed been fixed in version 13.2.

thanks!