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Added method for buildin a dodecahedron with faces triangulated witho…
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…ut a central point
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@cignoni
cignoni committed Nov 7, 2024
1 parent 390cd5b commit dd5b2f8
Showing 1 changed file with 86 additions and 31 deletions.
117 changes: 86 additions & 31 deletions vcg/complex/algorithms/create/platonic.h
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Original file line number Diff line number Diff line change
Expand Up @@ -71,6 +71,50 @@ void Tetrahedron(TetraMeshType &in)
(*fi).V(0)=ivp[3]; (*fi).V(1)=ivp[2]; (*fi).V(2)=ivp[1];
}

template <class DodMeshType>
void DodecahedronTri(DodMeshType & in)
{
typedef typename DodMeshType::CoordType CoordType;

const double phi = (1 + std::sqrt(5)) / 2; // Golden ratio
const double a = 1 / std::sqrt(3);
const double b = a / phi;
const double c = a * phi;

std::vector<std::array<double, 3>> vertices = {
{a, a, a}, {a, a, -a}, {a, -a, a}, {a, -a, -a},
{-a, a, a}, {-a, a, -a}, {-a, -a, a}, {-a, -a, -a},
{0, b, c}, {0, b, -c}, {0, -b, c}, {0, -b, -c},
{b, c, 0}, {b, -c, 0}, {-b, c, 0}, {-b, -c, 0},
{c, 0, b}, {c, 0, -b}, {-c, 0, b}, {-c, 0, -b}
};
for(size_t i = 0; i < vertices.size(); i++) {
Allocator<DodMeshType>::AddVertex(in, CoordType(vertices[i][0], vertices[i][1], vertices[i][2]));
}

std::vector<std::array<int, 5>> faces = {
{0, 8, 10, 2, 16},
{0, 16, 17, 1, 12},
{0, 12, 14, 4, 8},
{5, 14, 12, 1, 9},
{5, 19, 18, 4, 14},
{5, 9, 11, 7, 19},
{3, 11, 9, 1, 17},
{3, 13, 15, 7, 11},
{3, 17, 16, 2, 13},
{6, 18, 19, 7, 15},
{6, 15, 13, 2, 10},
{6, 10, 8, 4, 18}
};
for(size_t i = 0; i < faces.size(); i++) {
Allocator<DodMeshType>::AddFace(in, faces[i][0], faces[i][1], faces[i][2]);
in.face.back().SetF(2);
Allocator<DodMeshType>::AddFace(in, faces[i][0], faces[i][2], faces[i][3]);
in.face.back().SetF(0); in.face.back().SetF(2);
Allocator<DodMeshType>::AddFace(in, faces[i][0], faces[i][3], faces[i][4]);
in.face.back().SetF(0);
}
}

/// builds a Dodecahedron,
/// (each pentagonal face is composed by 5 triangles)
Expand Down Expand Up @@ -1124,18 +1168,15 @@ void Cylinder(int slices, int stacks, MeshType & m, bool capped=false)
}
}



class _SphFace;
class _SphVertex;
struct _SphUsedTypes : public UsedTypes< Use<_SphVertex> ::AsVertexType,
Use<_SphFace> ::AsFaceType>{};

class _SphVertex : public Vertex<_SphUsedTypes, vertex::Coord3f, vertex::Normal3f, vertex::BitFlags >{};
class _SphFace : public Face< _SphUsedTypes, face::VertexRef, face::Normal3f, face::BitFlags, face::FFAdj > {};
class _SphMesh : public tri::TriMesh< std::vector<_SphVertex>, std::vector<_SphFace> > {};


/** Given a mesh, it builds a new mesh composed by a set of solid prisms, one for each face.
* it supports faux edges polygonal meshes
* @param mIn input mesh
* @param mOut output mesh
* @param height height of the prism
* @param inset how much is contracted each face.
* @param smoothFlag if true, the output mesh is smoothed
*/

template <class MeshType>
void BuildPrismFaceShell(MeshType &mIn, MeshType &mOut, float height=0, float inset=0, bool smoothFlag=false )
{
Expand All @@ -1155,34 +1196,48 @@ void BuildPrismFaceShell(MeshType &mIn, MeshType &mOut, float height=0, float in
std::vector<FacePointer> faceVec;
tri::PolygonSupport<MeshType,MeshType>::ExtractPolygon(&(mIn.face[i]),vertVec,faceVec);
size_t vn = vertVec.size();
size_t fn = faceVec.size();

CoordType nf(0,0,0);
CoordType extrude_dir(0,0,0);
for(size_t j=0;j<faceVec.size();++j)
nf+=vcg::NormalizedTriangleNormal(*faceVec[j]) * DoubleArea(*faceVec[j]);
nf.Normalize();
nf = nf*height/2.0f;

extrude_dir+=vcg::NormalizedTriangleNormal(*faceVec[j]) * DoubleArea(*faceVec[j]);
extrude_dir.Normalize();
extrude_dir = extrude_dir*height/2.0f;
CoordType bary(0,0,0);
for(size_t j=0;j<faceVec.size();++j)
bary+= Barycenter(*faceVec[j]);
bary/=float(faceVec.size());

// Add vertices (alternated top and bottom)
tri::Allocator<MeshType>::AddVertex(faceM, bary+nf);
tri::Allocator<MeshType>::AddVertex(faceM, bary-nf);
// Add vertices
// We keeping maps from old vertex to new vertex
std::map<size_t,size_t> topVertMap;
std::map<size_t,size_t> botVertMap;

tri::Allocator<MeshType>::AddVertex(faceM, bary+extrude_dir);
tri::Allocator<MeshType>::AddVertex(faceM, bary-extrude_dir);
for(size_t j=0;j<vn;++j){
CoordType delta = (vertVec[j]->P() - bary);
delta.Normalize();
delta = delta*inset;
tri::Allocator<MeshType>::AddVertex(faceM, vertVec[j]->P()-delta+nf);
tri::Allocator<MeshType>::AddVertex(faceM, vertVec[j]->P()-delta-nf);
tri::Allocator<MeshType>::AddVertex(faceM, vertVec[j]->P()-delta+extrude_dir);
topVertMap[tri::Index(mIn,vertVec[j])] = tri::Index(faceM,faceM.vert.back());
tri::Allocator<MeshType>::AddVertex(faceM, vertVec[j]->P()-delta-extrude_dir);
botVertMap[tri::Index(mIn,vertVec[j])] = tri::Index(faceM,faceM.vert.back());
}

// Build top and bottom faces
for(size_t j=0;j<vn;++j)
tri::Allocator<MeshType>::AddFace(faceM, 0, 2+(j+0)*2, 2+((j+1)%vn)*2 );
for(size_t j=0;j<vn;++j)
tri::Allocator<MeshType>::AddFace(faceM, 1, 3+((j+1)%vn)*2, 3+(j+0)*2 );
// Build top and bottom faces using the original faces retrieved by the ExtractPolygon
for(size_t j=0;j<fn;++j)
tri::Allocator<MeshType>::AddFace(faceM,
topVertMap[tri::Index(mIn, faceVec[j]->V(0))],
topVertMap[tri::Index(mIn, faceVec[j]->V(1))],
topVertMap[tri::Index(mIn, faceVec[j]->V(2))]);

for(size_t j=0;j<fn;++j)
tri::Allocator<MeshType>::AddFace(faceM,
botVertMap[tri::Index(mIn, faceVec[j]->V(0))],
botVertMap[tri::Index(mIn, faceVec[j]->V(1))],
botVertMap[tri::Index(mIn, faceVec[j]->V(2))]);

// Build side strip
for(size_t j=0;j<vn;++j){
Expand All @@ -1192,12 +1247,12 @@ void BuildPrismFaceShell(MeshType &mIn, MeshType &mOut, float height=0, float in
tri::Allocator<MeshType>::AddFace(faceM, 2+ j0*2 + 1 , 2+ j1*2+1, 2+j1*2+0);
}

for(size_t j=0;j<2*vn;++j)
faceM.face[j].SetS();

if(smoothFlag)
{
tri::UpdateTopology<MeshType>::FaceFace(faceM);
for(size_t j=0;j<2*vn;++j)
faceM.face[j].SetS();

tri::UpdateTopology<MeshType>::FaceFace(faceM);
tri::UpdateFlags<MeshType>::FaceBorderFromFF(faceM);
tri::Refine(faceM, MidPoint<MeshType>(&faceM),0,true);
tri::Refine(faceM, MidPoint<MeshType>(&faceM),0,true);
Expand Down

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