From 8af9ef7f075c6172988c14097b2c9ebb8f7a7c3f Mon Sep 17 00:00:00 2001
From: Paul McCarthy <pauldmccarthy@gmail.com>
Date: Fri, 12 Apr 2019 15:21:02 +0100
Subject: [PATCH] RF: Mesh class potentially stores teo copies of triangles
with opposite winding order, to account for the possibility that different
vertex sets require different orders.
---
fsl/data/mesh.py | 56 +++++++++++++++++++++++++-----------------------
1 file changed, 29 insertions(+), 27 deletions(-)
diff --git a/fsl/data/mesh.py b/fsl/data/mesh.py
index f5ca20ade..e581c9603 100644
--- a/fsl/data/mesh.py
+++ b/fsl/data/mesh.py
@@ -98,6 +98,12 @@ class Mesh(notifier.Notifier, meta.Meta):
selectedVertices
vertexSets
+ .. note:: Internally the ``Mesh`` class may store two versions of the
+ triangles, with opposite unwinding orders. It keeps track of the
+ required triangle unwinding order for each vertex set, so that
+ the :meth:`indices` method will return the appropriate copy for
+ the currently selected vertex set.
+
**Vertex data**
@@ -183,19 +189,17 @@ class Mesh(notifier.Notifier, meta.Meta):
self.__name = name
self.__dataSource = dataSource
- self.__indices = np.asarray(indices).reshape((-1, 3))
- self.__nvertices = self.__indices.max() + 1
-
- # This attribute is used to store
- # the currently selected vertex set,
- # used as a kety into all of the
- # dictionaries below.
- self.__selected = None
-
- # Flag used to keep track of whether
- # the triangle winding order has been
- # "fixed" - see the addVertices method.
- self.__fixed = False
+ self.__nvertices = indices.max() + 1
+ self.__selected = None
+
+ # We potentially store two copies of
+ # the indices, with opposite unwinding
+ # orders. The vindices dict stores refs
+ # to one or the other for each vertex
+ # set.
+ self.__indices = np.asarray(indices).reshape((-1, 3))
+ self.__fixedIndices = None
+ self.__vindices = collections.OrderedDict()
# All of these are populated
# in the addVertices method
@@ -287,7 +291,7 @@ class Mesh(notifier.Notifier, meta.Meta):
@property
def indices(self):
"""The ``(M, 3)`` triangles of this mesh. """
- return self.__indices
+ return self.__vindices[self.__selected]
@property
@@ -297,7 +301,7 @@ class Mesh(notifier.Notifier, meta.Meta):
"""
selected = self.__selected
- indices = self.__indices
+ indices = self.__vindices[selected]
vertices = self.__vertices[selected]
fnormals = self.__faceNormals.get(selected, None)
@@ -315,7 +319,7 @@ class Mesh(notifier.Notifier, meta.Meta):
"""
selected = self.__selected
- indices = self.__indices
+ indices = self.__vindices[selected]
vertices = self.__vertices[selected]
vnormals = self.__vertNormals.get(selected, None)
@@ -334,10 +338,8 @@ class Mesh(notifier.Notifier, meta.Meta):
``((xlow, ylow, zlow), (xhigh, yhigh, zhigh))``
"""
-
lo = self.__loBounds[self.__selected]
hi = self.__hiBounds[self.__selected]
-
return lo, hi
@@ -411,26 +413,26 @@ class Mesh(notifier.Notifier, meta.Meta):
self.nvertices))
self.__vertices[key] = vertices
+ self.__vindices[key] = self.__indices
self.__loBounds[key] = lo
self.__hiBounds[key] = hi
if select:
self.vertices = key
- # indices already fixed?
- if fixWinding and (not self.__fixed):
- indices = self.indices
- normals = self.normals
- needsFix = needsFixing(vertices, indices, normals, lo, hi)
- self.__fixed = True
+ if fixWinding:
+ indices = self.__indices
+ normals = self.normals
+ needsFix = needsFixing(vertices, indices, normals, lo, hi)
# See needsFixing documentation
if needsFix:
- indices[:, [1, 2]] = indices[:, [2, 1]]
+ if self.__fixedIndices is None:
+ self.__fixedIndices = indices[:, [0, 2, 1]]
- for k, fn in self.__faceNormals.items():
- self.__faceNormals[k] = fn * -1
+ self.__vindices[ key] = self.__fixedIndices
+ self.__faceNormals[key] = normals * -1
return vertices
--
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