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Modified rasterization algorithm to generate samples from buffer areas outside (texture space) border edges

This commit is contained in:
Luigi Malomo 2010-02-09 19:10:22 +00:00
parent 9fee205755
commit 8465fa432c
1 changed files with 147 additions and 64 deletions
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135
vcg/complex/trimesh/point_sampling.h
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@ -43,6 +43,7 @@ sampling strategies (montecarlo, stratified etc).
#include <vcg/complex/trimesh/update/normal.h>
#include <vcg/complex/trimesh/update/flag.h>
#include <vcg/space/box2.h>
#include <vcg/space/segment2.h>
namespace vcg
{
namespace tri
@ -99,10 +100,11 @@ class TrivialSampler
sampleVec->push_back(f.P(0)*p[0] + f.P(1)*p[1] +f.P(2)*p[2] );
}
void AddTextureSample(const FaceType &, const CoordType &, const Point2i &)
void AddTextureSample(const FaceType &, const CoordType &, const Point2i &, float )
{
// Retrieve the color of the sample from the face f using the barycentric coord p
// and write that color in a texture image at position tp[0],tp[1]
// and write that color in a texture image at position <tp[0], texHeight-tp[1]>
// if edgeDist is > 0 then the corrisponding point is affecting face color even if outside the face area (in texture space)
}
}; // end class TrivialSampler
@ -527,8 +529,8 @@ static void FaceSubdivision(MetroMesh & m, VertexSampler &ps,int sampleNum, bool
//qDebug("samplePerAreaUnit %f",samplePerAreaUnit);
std::vector<FacePointer> faceVec;
FillAndShuffleFacePointerVector(m,faceVec);
tri::UpdateNormals<MetroMesh>::PerFaceNormalized(m);
tri::UpdateFlags<MetroMesh>::FaceProjection(m);
vcg::tri::UpdateNormals<MetroMesh>::PerFaceNormalized(m);
vcg::tri::UpdateFlags<MetroMesh>::FaceProjection(m);
double floatSampleNum = 0.0;
int faceSampleNum;
// Subdivision sampling.
@ -769,11 +771,16 @@ static void FaceSimilar(MetroMesh & m, VertexSampler &ps,int sampleNum, bool dua
// con due parametri x,y di tipo S esempio:
// class Foo { public void operator()(int x, int y ) { ??? } };
static void SingleFaceRaster(FaceType &f, VertexSampler &ps, const Point2<ScalarType> & v0, const Point2<ScalarType> & v1, const Point2<ScalarType> & v2)
{
typedef ScalarType S;
// This function does rasterization with a safety buffer area, thus accounting some points actually outside triangle area
// The safety area samples are generated according to face flag BORDER which should be true for texture space border edges
// Use correctSafePointsBaryCoords = true to map safety texels to closest point barycentric coords (on edge).
static void SingleFaceRaster(typename MetroMesh::FaceType &f, VertexSampler &ps,
const Point2<typename MetroMesh::ScalarType> & v0,
const Point2<typename MetroMesh::ScalarType> & v1,
const Point2<typename MetroMesh::ScalarType> & v2,
bool correctSafePointsBaryCoords=true)
{
typedef typename MetroMesh::ScalarType S;
// Calcolo bounding box
Box2i bbox;
@ -786,6 +793,7 @@ static void SingleFaceRaster(FaceType &f, VertexSampler &ps, const Point2<Scala
if(bbox.min[1]>int(v2[1])) bbox.min[1]=int(v2[1]);
else if(bbox.max[1]<int(v2[1])) bbox.max[1]=int(v2[1]);
// Calcolo versori degli spigoli
Point2<S> d10 = v1 - v0;
Point2<S> d21 = v2 - v1;
@ -803,31 +811,95 @@ static void SingleFaceRaster(FaceType &f, VertexSampler &ps, const Point2<Scala
S dn0 = -d10[0];
S dn1 = -d21[0];
S dn2 = -d02[0];
// Rasterizzazione
//Calculating orientation
bool flipped = !(d02 * vcg::Point2<S>(-d10[1], d10[0]) >= 0);
// Calculating border edges
Segment2<S> borderEdges[3];
S edgeLength[3];
unsigned char edgeMask = 0;
if (f.IsB(0)) {
borderEdges[0] = Segment2<S>(v0, v1);
edgeLength[0] = borderEdges[0].Length();
edgeMask |= 1;
}
if (f.IsB(1)) {
borderEdges[1] = Segment2<S>(v1, v2);
edgeLength[1] = borderEdges[1].Length();
edgeMask |= 2;
}
if (f.IsB(2)) {
borderEdges[2] = Segment2<S>(v2, v0);
edgeLength[2] = borderEdges[2].Length();
edgeMask |= 4;
}
// Rasterizzazione
double de = v0[0]*v1[1]-v0[0]*v2[1]-v1[0]*v0[1]+v1[0]*v2[1]-v2[0]*v1[1]+v2[0]*v0[1];
for(int x=bbox.min[0];x<=bbox.max[0];++x)
for(int x=bbox.min[0]-1;x<=bbox.max[0]+1;++x)
{
bool in = false;
S n0 = b0;
S n1 = b1;
S n2 = b2;
for(int y=bbox.min[1];y<=bbox.max[1];++y)
S n[3] = { b0-db0-dn0, b1-db1-dn1, b2-db2-dn2};
for(int y=bbox.min[1]-1;y<=bbox.max[1]+1;++y)
{
if( (n0>=0 && n1>=0 && n2>=0) || (n0<=0 && n1<=0 && n2<=0) )
if((n[0]>=0 && n[1]>=0 && n[2]>=0) || (n[0]<=0 && n[1]<=0 && n[2]<=0))
{
CoordType baryCoord;
typename MetroMesh::CoordType baryCoord;
baryCoord[0] = double(-y*v1[0]+v2[0]*y+v1[1]*x-v2[0]*v1[1]+v1[0]*v2[1]-x*v2[1])/de;
baryCoord[1] = -double( x*v0[1]-x*v2[1]-v0[0]*y+v0[0]*v2[1]-v2[0]*v0[1]+v2[0]*y)/de;
baryCoord[2] = 1-baryCoord[0]-baryCoord[1];
ps.AddTextureSample(f, baryCoord, Point2i(x,y));
ps.AddTextureSample(f, baryCoord, Point2i(x,y), 0);
in = true;
} else if(in) break;
n0 += dn0;
n1 += dn1;
n2 += dn2;
} else {
// Check whether a pixel outside (on a border edge side) triangle affects color inside it
Point2<S> px(x, y);
Point2<S> closePoint;
int closeEdge = -1;
S minDst = FLT_MAX;
// find the closest point (on some edge) that lies on the 2x2 squared neighborhood of the considered point
for (int i=0, t=0; t<2 && i<3 && (edgeMask>>i)%2 ; ++i)
{
Point2<S> close;
S dst;
if ( (!flipped && n[i]<0 || flipped && n[i]>0) &&
(dst = ((close = ClosestPoint(borderEdges[i], px)) - px).Norm()) < minDst &&
close.X() > px.X()-1 && close.X() < px.X()+1 &&
close.Y() > px.Y()-1 && close.Y() < px.Y()+1)
{
minDst = dst;
closePoint = close;
closeEdge = i;
++t;
}
}
if (closeEdge >= 0)
{
typename MetroMesh::CoordType baryCoord;
if (correctSafePointsBaryCoords)
{
// Add x,y sample with closePoint barycentric coords (on edge)
baryCoord[closeEdge] = (closePoint - borderEdges[closeEdge].P(1)).Norm()/edgeLength[closeEdge];
baryCoord[(closeEdge+1)%3] = 1 - baryCoord[closeEdge];
baryCoord[(closeEdge+2)%3] = 0;
} else {
// Add x,y sample with his own barycentric coords (off edge)
baryCoord[0] = double(-y*v1[0]+v2[0]*y+v1[1]*x-v2[0]*v1[1]+v1[0]*v2[1]-x*v2[1])/de;
baryCoord[1] = -double( x*v0[1]-x*v2[1]-v0[0]*y+v0[0]*v2[1]-v2[0]*v0[1]+v2[0]*y)/de;
baryCoord[2] = 1-baryCoord[0]-baryCoord[1];
}
ps.AddTextureSample(f, baryCoord, Point2i(x,y), minDst);
in = true;
} else if (in) break;
}
n[0] += dn0;
n[1] += dn1;
n[2] += dn2;
}
b0 += db0;
b1 += db1;
@ -1109,7 +1181,18 @@ static void PoissonDisk(MetroMesh &origMesh, VertexSampler &ps, MetroMesh &monte
//template <class MetroMesh>
//void Sampling<MetroMesh>::SimilarFaceSampling()
static void Texture(MetroMesh & m, VertexSampler &ps, int textureWidth, int textureHeight)
// This function also generates samples outside faces if those affects faces in texture space.
// Use correctSafePointsBaryCoords = true to map safety texels to closest point barycentric coords (on edge)
// otherwise obtained samples will map to barycentric coord actually outside face
//
// If you don't need to get those extra points clear faces Border Flags
// vcg::tri::UpdateFlags<Mesh>::FaceClearB(m);
//
// Else make sure to update border flags from texture space FFadj
// vcg::tri::UpdateTopology<Mesh>::FaceFaceFromTexCoord(m);
// vcg::tri::UpdateFlags<Mesh>::FaceBorderFromFF(m);
static void Texture(MetroMesh & m, VertexSampler &ps, int textureWidth, int textureHeight, bool correctSafePointsBaryCoords=true)
{
FaceIterator fi;
@ -1118,9 +1201,9 @@ static void Texture(MetroMesh & m, VertexSampler &ps, int textureWidth, int text
{
Point2f ti[3];
for(int i=0;i<3;++i)
ti[i]=Point2f((*fi).WT(i).U() * textureWidth, (*fi).WT(i).V() * textureHeight);
SingleFaceRaster(*fi, ps, ti[0],ti[1],ti[2]);
ti[i]=Point2f((*fi).WT(i).U() * textureWidth - 0.5, (*fi).WT(i).V() * textureHeight + 0.5);
// +/- 0.5 constants are used to obtain correct texture mapping
SingleFaceRaster(*fi, ps, ti[0],ti[1],ti[2], correctSafePointsBaryCoords);
}
}