fix index bug in splines

Author: mikedh

README.md

@@ -8,7 +8,7 @@ Trimesh is a pure Python (2.7- 3.3+) library for loading and using [triangular m
 
 The API is mostly stable, but this should not be relied on and is not guaranteed; install a specific version if you plan on deploying something using trimesh as a backend.
 
-Pull requests are hugely appreciated and responded to promptly! If you'd like to contribute, here is an [up to date list of potential enhancements](https://github.com/mikedh/trimesh/issues/199) although things not on that list are also welcome. Also, some [general advice for writing mesh code in Python and Numpy.](https://github.com/mikedh/trimesh/blob/master/trimesh/io/README.md)
+Pull requests are highly appreciated and are responded to promptly! If you'd like to contribute, here is an [up to date list of potential enhancements](https://github.com/mikedh/trimesh/issues/199) although things not on that list are also welcome. Also, some [general advice for writing mesh code in Python and Numpy.](https://github.com/mikedh/trimesh/blob/master/trimesh/io/README.md)
 
 
 ## Basic Installation
@@ -17,13 +17,13 @@ The minimal requirements to import trimesh are
 [numpy](http://www.numpy.org/), [scipy](http://www.scipy.org) and
 [networkx](https://networkx.github.io). Installing other packages mentioned adds functionality but is **not required**.
 
-For the easiest install with only these minimal dependencies (slower ray queries, no vector path handling, mesh creation, viewer, etc):
+For the easiest install with only these minimal dependencies:
 
 ```bash
 pip install trimesh
 ```
 
-For more functionality, the easiest way to get a full `trimesh` install is a [conda environment](https://conda.io/miniconda.html):
+For more functionality, like faster ray queries (`pyembree`), vector path handling (`shapely` and `rtree`), preview windows (`pyglet`), faster cache checks (`xxhash`) and more, the easiest way to get a full `trimesh` install is a [conda environment](https://conda.io/miniconda.html):
 
 ```bash
 # this will install all soft dependencies available on your current platform

setup.py

@@ -57,6 +57,7 @@
                                'msgpack',
                                'pillow',
                                'requests',
+                               'xxhash',
                                'colorlog'],
                       'all': ['lxml',
                               'pyglet',

trimesh/path/curve.py

@@ -82,6 +82,7 @@ def discretize_bspline(control,
     ipl = np.linspace(knots[0], knots[-1], count)
     discrete = splev(ipl, [knots, control.T, degree])
     discrete = np.column_stack(discrete)
+
     return discrete
 
 

trimesh/path/path.py

@@ -467,6 +467,10 @@ def merge_vertices(self):
                                                digits=digits)
         self.vertices = self.vertices[unique]
         for entity in self.entities:
+            # don't screw up control- point- knot relationship
+            if type(entity).__name__ in 'BSpline Bezier':
+                entity.points = inverse[entity.points]
+                continue
             # if we merged duplicate vertices, the entity may contain
             # multiple references to the same vertex
             entity.points = grouping.merge_runs(inverse[entity.points])

trimesh/version.py

@@ -1 +1 @@
-__version__ = '2.33.41'
+__version__ = '2.33.42'