bool Grid::intersect(const Ray &r, Hit &h, float tmin)
{
//Prepare the Material objects
Vec3f diffuseColor(1, 1, 1);
Vec3f specularColor(0, 0, 0);
float exponent = 1;
Vec3f reflectiveColor(0, 0, 0);
Vec3f transparentColor(0, 0, 0);
float indexOfRefraction = 1;
PhongMaterial *m = new PhongMaterial(diffuseColor, specularColor, exponent,
reflectiveColor, transparentColor, indexOfRefraction);
//Start to do DDA
MarchingInfo mi;
initializeRayMarch(mi, r, tmin);
bool hitSomething = false;
int i, j, k;
do {
mi.getIndices(i, j, k);
printf("The current point is:%d,%d,%d\n", i, j, k);
if (mObjects[offset(i, j, k)].getNumObjects() > 0) {
h.set(mi.get_tmin(), m, mi.getNormal(), r);
return true;
}
mi.nextCell();
} while(i < mXSize && j < mYSize && k < mZSize);
return false;
}
void Grid::initializeRayMarch(MarchingInfo &mi, const Ray &r, float tmin) const
{
Vec3f rayOrigin = r.getOrigin();
Vec3f rayDir = r.getDirection();
Vec3f boxMin = mpBox->getMin();
Vec3f boxMax = mpBox->getMax();
float rayT;
if (mpBox->Inside(rayOrigin))
rayT = 0.0;
else if (!mpBox->IntersectP(r, &rayT))
{
return;
}
printf("rayT=%f\n", rayT);
Vec3f gridIntersect = r.pointAtParameter(rayT);
cout << "gridIntersect=" << gridIntersect << endl;
cout << "Box min=" << mpBox->getMin() << endl;
printf("mVoxel:%d, %d, %d \n", mVoxel[0], mVoxel[1], mVoxel[2]);
//MarchingInfo for indices
int pos[3];
int axis;
int sign[3];
float delta[3];
float next[3];
int indices[3];
for (axis = 0; axis < 3; axis++) {
pos[axis] = posToVoxel(gridIntersect, axis);
if (rayDir[axis] != 0)
sign[axis] = rayDir[axis] > 0 ? 1 : -1;
if (sign[axis] >= 0) {
next[axis] = rayT +
(voxelToPos(pos[axis]+1, axis) - gridIntersect[axis])/rayDir[axis];
delta[axis] = mVoxel[axis] / rayDir[axis];
}
else {
next[axis] = rayT +
(voxelToPos(pos[axis], axis) - gridIntersect[axis])/rayDir[axis];
delta[axis] = mVoxel[axis] / rayDir[axis];
}
}
printf("Indices:%d, %d, %d \n", pos[0], pos[1], pos[2]);
mi.setIndices(pos[0], pos[1], pos[2]);
mi.setSign(sign[0], sign[1], sign[2]);
mi.setDelta(delta[0], delta[1], delta[2]);
mi.setNext(next[0], next[1], next[2]);
mi.set_tmin(rayT);
}
bool Grid::shadowIntersect(const Ray &r, Hit &h, float tmin)
{
MarchingInfo march;
initialRayMarch(march,r,tmin);
int currentI = march.GetI();
int currentJ = march.GetJ();
int currentK = march.GetK();
float currentT = march.GetT();
int numObjects;
Object3DVector isAlreadyIntersect;
while(currentI>=0 && currentI<nx && currentJ>=0 && currentJ<ny && currentK>=0 && currentK<nz)
{
RayTracingStats::IncrementNumGridCellsTraversed();
Object3DVector ¤tVector = isOpaque[currentI][currentJ][currentK];
numObjects = currentVector.getNumObjects();
for(int i=0; i<numObjects; ++i)
{
if(isAlreadyIntersect.isInside(currentVector.getObject(i)))
continue;
RayTracingStats::IncrementNumIntersections();
if(currentVector.getObject(i)->intersect(r,h,tmin))
return true;
isAlreadyIntersect.addObject(currentVector.getObject(i));
}
march.nextCell();
currentI = march.GetI();
currentJ = march.GetJ();
currentK = march.GetK();
currentT = march.GetT(); //折射或反射，shadow时，光线圆点会在grid内
}
numObjects = others.getNumObjects();
for(int i=0; i<numObjects; i++)
{
if(others.getObject(i)->intersect(r,h,tmin))
return true;
}
return false;
}
bool Grid::intersect(const Ray &r, Hit &h, float tmin)
{
MarchingInfo march;
initialRayMarch(march,r,tmin);
int currentI = march.GetI();
int currentJ = march.GetJ();
int currentK = march.GetK();
float currentT = march.GetT();
int numObjects;
//Object3DVector currentVector; 绝对不能新建一个Object3DVector，然后把isOpaque的值赋给这个Object3DVector，因为当这个函数结束时，会把Object3DVector销毁，对应的指针指向的对象也会被销毁。
//当然还有一种方法是定义一个Object3DVector指针
//printf("i:%d j:%d currentI:%d currentJ:%d currentK:%d\n",i,j,currentI,currentJ,currentK);
Object3DVector isAlreadyIntersect;
while(currentI>=0 && currentI<nx && currentJ>=0 && currentJ<ny && currentK>=0 && currentK<nz)
{
RayTracingStats::IncrementNumGridCellsTraversed();
Object3DVector* currentVector = &isOpaque[currentI][currentJ][currentK];
numObjects = currentVector->getNumObjects();
//printf("%d %d %d\n",currentI,currentJ,currentK);
for(int i=0; i<numObjects; ++i)
{
//already intersected object don't need intersect again
if(isAlreadyIntersect.isInside(currentVector->getObject(i)))
continue;
RayTracingStats::IncrementNumIntersections();
currentVector->getObject(i)->intersect(r,h,tmin);
isAlreadyIntersect.addObject(currentVector->getObject(i));
}
if(h.getMaterial()!=NULL && h.getT()>=currentT && h.getT()<=march.GetNext_x() && h.getT()<=march.GetNext_y() && h.getT()<=march.GetNext_z())
{
return true;
}
march.nextCell();
currentI = march.GetI();
currentJ = march.GetJ();
currentK = march.GetK();
currentT = march.GetT(); //折射或反射，shadow时，光线圆点会在grid内
}
numObjects = others.getNumObjects();
for(int i=0; i<numObjects; i++)
{
others.getObject(i)->intersect(r,h,tmin);
}
if(h.getMaterial()!=NULL) //这里有问题，因为如果没有和平面相交的话，h的material也有可能不是null
return true;
return false;
}
void Grid::initialRayMarch(MarchingInfo &mi, const Ray &r, float tmin) const
{
Vec3f rayOri = r.getOrigin();
Vec3f rayDir = r.getDirection();
float tbottom,ttop,tfront,tback,tleft,tright,tc;
float dtx,dty,dtz;
int celli,cellj,cellk;
float tnext_x,tnext_y,tnext_z;
int signx,signy,signz;
signx = (rayDir.x()>=0) ? 1 : -1;
signy = (rayDir.y()>=0) ? 1 : -1;
signz = (rayDir.z()>=0) ? 1 : -1;
//需要求绝对值 这里rayDir.x()等于0没有处理
dtx = abs(dx / rayDir.x());
dty = abs(dy / rayDir.y());
dtz = abs(dz / rayDir.z());
Vec3f normal;
Vec3f rayOriTmin = rayOri + rayDir * tmin;
//这里临界值要注意
//inside;
if(max.x()>rayOriTmin.x()&&min.x()<rayOriTmin.x()&&max.y()>rayOriTmin.y()&&min.y()<rayOriTmin.y()&&max.z()>rayOriTmin.z()&&min.z()<rayOriTmin.z()) //忽略了tmin的作用
{
celli = (int)((rayOriTmin.x()-min.x())/dx);
cellj = (int)((rayOriTmin.y()-min.y())/dy);
cellk = (int)((rayOriTmin.z()-min.z())/dz);
if(Utility::isZero(rayDir.x()))
tnext_x = 10000;
else if(signx == -1) //如果反方向的话，求tnext不需要加signx 谢谢大师提醒
tnext_x = (min.x()+celli*dx-rayOri.x())/rayDir.x();
else
tnext_x = (min.x()+(celli+signx)*dx-rayOri.x())/rayDir.x();
if(Utility::isZero(rayDir.y()))
tnext_y = 10000;
else if(signy == -1)
tnext_y = (min.y()+cellj*dy-rayOri.y())/rayDir.y();
else
tnext_y = (min.y()+(cellj+signy)*dy-rayOri.y())/rayDir.y();
if(Utility::isZero(rayDir.z()))
tnext_z = 10000;
else if(signz == -1)
tnext_z = (min.z()+cellk*dz-rayOri.z())/rayDir.z();
else
tnext_z = (min.z()+(cellk+signz)*dz-rayOri.z())/rayDir.z();
//这里tmin如何修改
mi.Set(0,celli,cellj,cellk,tnext_x,tnext_y,tnext_z,dtx,dty,dtz,signx,signy,signz,normal);
}
else //outside
{
float t1x,t1y,t1z;
float t2x,t2y,t2z;
float tnear,tfar;
if(Utility::isZero(rayDir.x()))
{
tleft = 0;
tright = 10000;
}
else
{
tleft = (min.x()-rayOri.x())/rayDir.x();
tright = (max.x()-rayOri.x())/rayDir.x();
}
if(Utility::isZero(rayDir.y()))
{
tbottom = 0;
ttop = 10000;
}
else
{
tbottom = (min.y()-rayOri.y())/rayDir.y();
ttop = (max.y()-rayOri.y())/rayDir.y();
}
if(Utility::isZero(rayDir.z()))
{
tback = 0;
tfront = 10000;
}
else
{
tback = (min.z()-rayOri.z())/rayDir.z();
tfront = (max.z()-rayOri.z())/rayDir.z();
}
t1x = (signx == 1) ? tleft : tright;
t2x = (signx == 1) ? tright : tleft;
t1y = (signy == 1) ? tbottom : ttop;
t2y = (signy == 1) ? ttop : tbottom;
t1z = (signz == 1) ? tback : tfront;
t2z = (signz == 1) ? tfront : tback;
tnear = Utility::getMax(t1x,t1y,t1z);
tfar = Utility::getMin(t2x,t2y,t2z);
if(tnear>tfar) //miss
{}
else if(tfar<tmin) //behind
{}
else //hit
{
tc = tnear;
//求i,j,k
if(rayOri.x()+rayDir.x()*tc+tmin < min.x()) //要加上0.0001
celli = -1;
else
celli = (int)((rayOri.x()+rayDir.x()*tc-min.x()-tmin)/dx); //减去0.0001是为了使边界也算交
if(rayOri.y()+rayDir.y()*tc+tmin < min.y())
cellj = -1;
else
cellj = (int)((rayOri.y()+rayDir.y()*tc-min.y()-tmin)/dy);
if(rayOri.z()+rayDir.z()*tc+tmin < min.z())
cellk = -1;
else
cellk = (int)((rayOri.z()+rayDir.z()*tc-min.z()-tmin)/dz);
//求tnext
if(Utility::isZero(rayDir.x()))
tnext_x = 10000;
else if(signx == -1) //如果反方向的话，求tnext不需要加signx 谢谢大师提醒
tnext_x = (min.x()+celli*dx-rayOri.x())/rayDir.x();
else
tnext_x = (min.x()+(celli+signx)*dx-rayOri.x())/rayDir.x();
if(Utility::isZero(rayDir.y()))
tnext_y = 10000;
else if(signy == -1)
tnext_y = (min.y()+cellj*dy-rayOri.y())/rayDir.y();
else
tnext_y = (min.y()+(cellj+signy)*dy-rayOri.y())/rayDir.y();
if(Utility::isZero(rayDir.z()))
tnext_z = 10000;
else if(signz == -1)
tnext_z = (min.z()+cellk*dz-rayOri.z())/rayDir.z();
else
tnext_z = (min.z()+(cellk+signz)*dz-rayOri.z())/rayDir.z();
if(Utility::isEqual(tc,tleft))
normal.Set(-1,0,0);
else if(Utility::isEqual(tc,tright))
normal.Set(1,0,0);
else if(Utility::isEqual(tc,tbottom))
normal.Set(0,-1,0);
else if(Utility::isEqual(tc,ttop))
normal.Set(0,1,0);
else if(Utility::isEqual(tc,tfront))
normal.Set(0,0,1);
else if(Utility::isEqual(tc,tback))
normal.Set(0,0,-1);
mi.Set(tc,celli,cellj,cellk,tnext_x,tnext_y,tnext_z,dtx,dty,dtz,signx,signy,signz,normal);
//printf("celli: %d cellj: %d cellk: %d \n",celli,cellj,cellk);
}
}
}
