MeshDrawer "linkSegment": Uneven Placement of Vertices

Okay, MeshDrawer is driving me up the wall now. :/

In attempting to make a small test-program to demonstrate a problem that I’ve been having with UV-mapping geometry generated by MeshDrawer, I bumped into another problem: “linkSegment” doesn’t seem to place the vertices for its segments as expected.

Let me demonstrate. Consider the following simple program:

from direct.showbase.ShowBase import ShowBase

from panda3d.core import NodePath, PandaNode, MeshDrawer, Vec3, Vec4

class Game(ShowBase):
    def __init__(self):

        self.pts = [Vec3(-2, 0, 0), Vec3(-1, 0, 0), Vec3(0, 0, 0), Vec3(1, 0, 0), Vec3(2, 0, 0)]

        self.meshDrawer = MeshDrawer()

        self.meshDrawerNP = self.meshDrawer.getRoot()

        tex = loader.loadTexture("colours.png")

        self.meshDrawer.begin(, self.render)

        frame = Vec4(0, 0, 0.25, 1)
        thickness = 1
        colour = Vec4(1, 1, 1, 1)

        for index, pt in enumerate(self.pts):
            if index > 1:
            self.meshDrawer.linkSegment(pt, frame, thickness, colour)
        self.meshDrawer.linkSegmentEnd(frame, colour)


app = Game()

And here below is the texture used:

This simply has MeshDrawer created link-segments from a set of evenly-spaced points, with evenly-spaced UVs, and applying a texture composed of even bands of colour.

However, as you may see if you run the program, the colours are not distributed evenly: some bands are significantly thicker than others!

Now, this might be thought to be a UV-mapping issue… But I used the “writeBam” method to save out the geometry produced, loaded it into PView, activated wireframe mode, and this is what I found:

For some reason the segments are not of equal size, despite being produced from points of equal spacing! :/

Naturally, this rather complicates UV-mapping when the texture is intended to proceed evenly along the strip of segments…

Once again, let me ask: Is this a bug in MeshDrawer? Am I doing something wrong? Is there a workaround, given that my goal is to apply a texture evenly to a dynamically-generated link-segment (i.e. with an updating set of points)?