Hi Lie,
Here is how I create vertex and normal buffers for OpenGL, hope it is
helpful.
def mesh_shape(self,shape):
if shape.IsNull():
return
BRepMesh_Mesh(shape,0.01)
t = Topo(shape)
numTriangles = 0
triangulations = []
faces = []
for aFace in t.faces():
loc = TopLoc_Location()
triangulation = BRep_Tool_Triangulation(aFace,loc)
faces.append(aFace)
if triangulation.IsNull() == False:
numTriangles += triangulation.GetObject().NbTriangles()
triangulations.append(triangulation)
normals = [0.]*numTriangles*3*3
triangles = [0.]*numTriangles*3*3
t = Topo(shape)
index = 0
for i in range(len(triangulations)):
triangulation = triangulations[i]
tris = triangulation.GetObject().Triangles()
nodes = triangulation.GetObject().Nodes()
prop = BRepGProp_Face(faces[i])
for j in range(1,triangulation.GetObject().NbTriangles()+1):
N1 = None
N2 = None
N3 = None
#Poly_Triangle
N1,N2,N3 = tris.Value(j).Get()
V1 = nodes.Value(N1)
V2 = nodes.Value(N2)
V3 = nodes.Value(N3)
triangles[index*9] = V1.X();
triangles[index*9+1] = V1.Y();
triangles[index*9+2] = V1.Z();
triangles[index*9+3] = V2.X();
triangles[index*9+4] = V2.Y();
triangles[index*9+5] = V2.Z();
triangles[index*9+6] = V3.X();
triangles[index*9+7] = V3.Y();
triangles[index*9+8] = V3.Z();
uv = triangulation.GetObject().UVNodes().Value(N1);
tmp = gp_Pnt()
norm = gp_Vec()
prop.Normal(uv.X(),uv.Y(),tmp,norm);
norm.Normalize();
normals[index*9]=norm.X();
normals[index*9+1]=norm.Y();
normals[index*9+2]=norm.Z();
norm.Normalize();
normals[index*9+3]=norm.X();
normals[index*9+4]=norm.Y();
normals[index*9+5]=norm.Z();
uv = triangulation.GetObject().UVNodes().Value(N3)
prop.Normal(uv.X(),uv.Y(),tmp,norm)
norm.Normalize()
normals[index*9+6]=norm.X()
normals[index*9+7]=norm.Y()
normals[index*9+8]=norm.Z()
index = index+1
On Sat, Sep 3, 2011 at 9:30 PM, Lie Pablo <lie...@gmail.com> wrote:
> István Csanády <istvancsanady@...> writes:
>
> >
> >
> > Hi All!
> >
> > If I give an topological incorrect shape to QuickTriangleMesh, it crashes
> if I
> call compute() (And it does not crash if I call compute_default_precision()
> but
> does not return any data). However the SimpleGUI can display it. Is it
> possible
> somehow to use the SimpleGUI's mesher algorithm (and curve discretizer)?
> I've
> attached the code. (Mac OSX 10.6, python 2.6)
> >
> > István
> >
> > Attachment (main.py): application/octet-stream, 5132 bytes
>
>
> Hi István,
>
> I'm working with QuickTriangleMesh and I found another problem... I get
> about
> half of the normals flipped. But if I save it straight away with
> StlAPI_Writer
> the normals are ok.
>
> All best
> Lie Pablo
>
>
> _______________________________________________
> Pythonocc-users mailing list
> Pythonocc-users@gna.org
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>
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