Finally fix my non-manifold-with-CageFork bug!

README.md

@@ -5,16 +5,6 @@
   behind this.
   
 ## Annoying/boring
-- Fix non-manifold bug at branch. (The edges must be *shared*. It is
-  not sufficient that the subdivided edges both lie incident on some
-  other edge and cover it completely. You must subdivide that larger
-  edge, and thus the triangle it lies on.)
-  - See cage.py and CageGen.to_mesh
-  - CageFork may need to supply some 'opening' cage that I use as
-    a basis for how I subdivide a 'closing' cage.  If I subdivide
-    the closing cage, then I must triangulate *after*, not before.
-  - classify_overlap might be unnecessary, but its classification may
-    have the right idea.
 - https://en.wikipedia.org/wiki/Polygon_triangulation - do this to
   fix my wave example!
   - http://www.polygontriangulation.com/2018/07/triangulation-algorithm.html
@@ -84,3 +74,4 @@
 - What are the limitations of using Cages?
 - Current system is very "generative".  Could I do basically L-system
   if I have rules for how a much is *refined*?  What about IFS?
+- Do this in Rust once I understand WTF I am doing

cage.py

@@ -179,7 +179,7 @@ class CageFork(object):
         return True
     def transition_from(self, cage):
         """Generate a transitional mesh to adapt the given starting Cage"""
-        print("DEBUG: Transition from {} to {}".format(cage.verts, self.verts))
+        #print("DEBUG: Transition from {} to {}".format(cage.verts, self.verts))
         vs = numpy.concatenate([cage.verts, self.verts])
         # Indices 0...offset-1 are from cage, rest are from self.verts
         offset = cage.verts.shape[0]
@@ -205,9 +205,9 @@ class CageGen(object):
         self.gen = gen
     def to_mesh(self, count=None, flip_order=False, loop=False, close_first=False,
                 close_last=False, join_fn=meshutil.join_boundary_simple):
-        #print("to_mesh(count={})".format(count))
         # Get 'opening' polygons of generator:
         cage_first = next(self.gen)
+        #print("DEBUG: to_mesh(count={}), cage_first={}".format(count, cage_first.verts))
         # TODO: Avoid 'next' here so that we can use a list, not solely a
         # generator/iterator.
         if cage_first.is_fork():
@@ -222,6 +222,7 @@ class CageGen(object):
         # Generate all polygons from there and connect them:
         #print(self.gen)
         for i, cage_cur in enumerate(self.gen):
+            #print("DEBUG: i={}, cage_cur={}, cage_last={}".format(i, cage_cur, cage_last.verts))
             #print("{}: {}".format(i, cage_cur))
             if count is not None and i >= count:
                 # We stop recursing here, so close things off if needed:
@@ -235,6 +236,7 @@ class CageGen(object):
             if cage_cur.is_fork():
                 # First, transition the cage properly:
                 mesh_trans = cage_cur.transition_from(cage_last)
+                meshes.append(mesh_trans)
                 # TODO: Clean up these recursive calls; parameters are ugly.
                 # Some of them also make no sense in certain combinations
                 # (e.g. loop with fork)
@@ -262,8 +264,5 @@ class CageGen(object):
                 else:
                     m = join_fn(b0, b1)
                 meshes.append(m)
-        # TODO: close_last?
-        # or should this just look for whether or not the
-        # generator ends here (without a CageFork)?
         mesh = meshutil.FaceVertexMesh.concat_many(meshes)
         return mesh

examples.py

@@ -147,7 +147,9 @@ def ram_horn_branch():
     def recur(xf, cage1, count):
         for i in range(count):
             if i > 0:
-                yield cage1.transform(xf)
+                c = cage1.transform(xf)
+                #print("DEBUG: recur, i={}, yield {}".format(i, c.verts))
+                yield c
             xf0 = xf
             xf = incr.compose(xf)
         # .compose(opening_boundary(i))
@@ -162,25 +164,26 @@ def ram_horn_branch():
                 dx, dy = -1, -1
             elif i == 3:
                 dx, dy = 1, -1
-            return meshutil.Transform().rotate([-dy,dx,0], -numpy.pi/6)
+            return meshutil.Transform().translate(0, 0, 0.5).rotate([-dy,dx,0], -numpy.pi/6)
         subdiv, trans_vs, trans_es = cage1.subdivide_deprecated()
         gens = [cage.CageGen(itertools.chain(
-                    #[cage_sub.transform(xf0)],
-                    recur(xf_sub(i).compose(xf0), cage_sub, 4)))
+                    [cage_sub.transform(xf)],
+                    recur(xf_sub(i).compose(xf), cage_sub, 8)))
                 for i,cage_sub in
                 enumerate(subdiv)]
-        yield cage.CageFork(gens, xf0.apply_to(trans_vs), trans_es)
-        # TODO: Figure out why this has a large gap now
-        # I seem to be producing a transition mesh that is degenerate,
-        # which means the starting cage and subdivided cage are lying right
-        # on top of each other.  Starting cage looks okay, so subdivided
-        # cage is probably what is wrong.
+        yield cage.CageFork(gens, xf.apply_to(trans_vs), trans_es)
+        # TODO: The starting cage needs to be one iteration *earlier*, and the
+        # subdivided cage is fine, but the generators likewise need to start
+        # one iteration earlier.  Look closely in Blender at the mesh,
+        # specifically just prior to the fork.
+        #
+        # xf0.apply_to(trans_vs) is identical to last cage yielded?
     cg = cage.CageGen(itertools.chain(
         [cage0],
-        recur(meshutil.Transform(), cage0, 4),
+        recur(meshutil.Transform(), cage0, 8),
     ))
     # TODO: if this is just a list it seems silly to require itertools
-    mesh = cg.to_mesh(count=8, close_first=True, close_last=True)
+    mesh = cg.to_mesh(count=32, close_first=True, close_last=True)
     return mesh
 
 def branch_test():
@@ -350,7 +353,8 @@ def main():
     fns = {
         ram_horn: "ramhorn.stl",
         ram_horn2: "ramhorn2.stl",
-        ram_horn3: "ramhorn3.stl",
+        # TODO: Fix
+        #ram_horn3: "ramhorn3.stl",
         ram_horn_branch: "ramhorn_branch.stl",
         twist: "twist.stl",
         twist_nonlinear: "twist_nonlinear.stl",