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//
// Copyright 2013 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
// names, trademarks, service marks, or product names of the Licensor
// and its affiliates, except as required to comply with Section 4(c) of
// the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
//------------------------------------------------------------------------------
// Tutorial description:
//
// This tutorial shows how to safely create Hbr meshes from arbitrary topology.
// Because Hbr is a half-edge data structure, it cannot represent non-manifold
// topology. Ensuring that the geometry used is manifold is a requirement to use
// Hbr safely. This tutorial presents some simple tests to detect inappropriate
// topology.
//
#include <opensubdiv/hbr/mesh.h>
#include <opensubdiv/hbr/catmark.h>
#include <cstdio>
//------------------------------------------------------------------------------
struct Vertex {
// Hbr minimal required interface ----------------------
Vertex() { }
Vertex(int /*i*/) { }
Vertex(Vertex const & src) {
_position[0] = src._position[0];
_position[1] = src._position[1];
_position[2] = src._position[2];
}
void Clear( void * =0 ) { }
void AddWithWeight(Vertex const &, float ) { }
void AddVaryingWithWeight(Vertex const &, float) { }
// Public interface ------------------------------------
void SetPosition(float x, float y, float z) {
_position[0]=x;
_position[1]=y;
_position[2]=z;
}
const float * GetPosition() const {
return _position;
}
private:
float _position[3];
};
typedef OpenSubdiv::HbrMesh<Vertex> Hmesh;
typedef OpenSubdiv::HbrFace<Vertex> Hface;
typedef OpenSubdiv::HbrVertex<Vertex> Hvertex;
typedef OpenSubdiv::HbrHalfedge<Vertex> Hhalfedge;
//------------------------------------------------------------------------------
// Non-manifold geometry from catmark_fan.h
//
// o
// /|
// / |
// / |
// / |
// o |
// | f2 |
// | |
// o--------+----o------------o
// / | / /
// / | / /
// / f0 | / f1 /
// / |/ /
// o------------ o------------o
//
// The shared edge of a fan is adjacent to 3 faces, and therefore non-manifold.
//
static float verts[8][3] = {{-1.0, 0.0, -1.0},
{-1.0, 0.0, 0.0},
{ 0.0, 0.0, 0.0},
{ 0.0, 0.0, -1.0},
{ 1.0, 0.0, 0.0},
{ 1.0, 0.0, -1.0},
{ 0.0, 1.0, 0.0},
{ 0.0, 1.0, -1.0}};
static int nverts = 8,
nfaces = 3;
static int facenverts[3] = { 4, 4, 4 };
static int faceverts[12] = { 0, 1, 2, 3,
3, 2, 4, 5,
3, 2, 6, 7 };
//------------------------------------------------------------------------------
int main(int, char **) {
OpenSubdiv::HbrCatmarkSubdivision<Vertex> * catmark =
new OpenSubdiv::HbrCatmarkSubdivision<Vertex>();
Hmesh * hmesh = new Hmesh(catmark);
Vertex v;
for (int i=0; i<nverts; ++i) {
v.SetPosition(verts[i][0], verts[i][1], verts[i][2]);
hmesh->NewVertex(i, v);
}
// Create the topology
int * fv = faceverts;
for (int i=0; i<nfaces; ++i) {
int nv = facenverts[i];
bool valid = true;
for(int j=0;j<nv;j++) {
Hvertex const * origin = hmesh->GetVertex(fv[j]),
* destination = hmesh->GetVertex(fv[(j+1)%nv]);
Hhalfedge const * opposite = destination->GetEdge(origin);
// Make sure that the vertices exist in the mesh
if (origin==NULL || destination==NULL) {
printf(" An edge was specified that connected a nonexistent vertex\n");
valid=false;
break;
}
// Check for a degenerate edge
if (origin == destination) {
printf(" An edge was specified that connected a vertex to itself\n");
valid=false;
break;
}
// Check that no more than 2 faces are adjacent to the edge
if (opposite && opposite->GetOpposite() ) {
printf(" A non-manifold edge incident to more than 2 faces was found\n");
valid=false;
break;
}
// Check that the edge is unique and oriented properly
if (origin->GetEdge(destination)) {
printf(" An edge connecting two vertices was specified more than once."
" It's likely that an incident face was flipped\n");
valid=false;
break;
}
}
if (valid) {
hmesh->NewFace(nv, fv, 0);
} else {
printf(" Skipped face %d\n", i);
}
fv+=nv;
}
hmesh->SetInterpolateBoundaryMethod(Hmesh::k_InterpolateBoundaryEdgeOnly);
hmesh->Finish();
printf("Created a fan with %d faces and %d vertices.\n",
hmesh->GetNumFaces(), hmesh->GetNumVertices());
delete hmesh;
delete catmark;
}
//------------------------------------------------------------------------------
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