Hi all (Robert)
A few things:
1. The logo reader seems to have stopped working?
osgviewer osg64.logo shows nothing on my version of osg. (svn checkout
at 23:rd of june).
Has there been any recent changes in the reader, because it worked
some while back...
2. Next thing: A fairly easy (unsure about its actual speedup though)
optimization for one specific file is toremove the numerous /V.x() in
the TangentSpaceGenerator.cpp.
Nevertheless, using the same divisor numerous time is not recomended....
Also, I was thinking, if you only need the Tangent (the normal is
usually already known) there could be some gain in not computing all
of the elements?
Usually calculating the Bi-Tangent in a shader is faster than
calculating it on the CPU and then sending it over to the GPU. So I
guess there could be an option on what to actually calculate.
But I also noticed that all of them seems to be necessary for the
calculation in the current implementation.
In an ideal world only the Tangent needs to be calculated (using the
existing Normal), right?
That would really speed things up.
But thats for the future :-)
#include <osgUtil/TangentSpaceGenerator>
#include <osg/Notify>
#include <osg/io_utils>
using namespace osgUtil;
TangentSpaceGenerator::TangentSpaceGenerator()
: osg::Referenced(),
T_(new osg::Vec4Array),
B_(new osg::Vec4Array),
N_(new osg::Vec4Array)
{
}
TangentSpaceGenerator::TangentSpaceGenerator(const
TangentSpaceGenerator ©, const osg::CopyOp ©op)
: osg::Referenced(copy),
T_(static_cast<osg::Vec4Array *>(copyop(copy.T_.get()))),
B_(static_cast<osg::Vec4Array *>(copyop(copy.B_.get()))),
N_(static_cast<osg::Vec4Array *>(copyop(copy.N_.get())))
{
}
void TangentSpaceGenerator::generate(osg::Geometry *geo, int
normal_map_tex_unit)
{
// check to see if vertex attributes indices exists, if so expand
them to remove them
if (geo->suitableForOptimization())
{
// removing coord indices so we don't have to deal with them
in the binormal code.
osg::notify(osg::INFO)<<"TangentSpaceGenerator::generate(Geometry*,int):
Removing attribute indices"<<std::endl;
geo->copyToAndOptimize(*geo);
}
const osg::Array *vx = geo->getVertexArray();
const osg::Array *nx = geo->getNormalArray();
const osg::Array *tx = geo->getTexCoordArray(normal_map_tex_unit);
if (!vx || !tx) return;
unsigned int vertex_count = vx->getNumElements();
if (geo->getVertexIndices() == NULL) {
T_->assign(vertex_count, osg::Vec4());
B_->assign(vertex_count, osg::Vec4());
N_->assign(vertex_count, osg::Vec4());
} else {
unsigned int index_count = geo->getVertexIndices()->getNumElements();
T_->assign(index_count, osg::Vec4());
B_->assign(index_count, osg::Vec4());
N_->assign(index_count, osg::Vec4());
indices_ = new osg::UIntArray();
unsigned int i;
for (i=0;i<index_count;i++) {
indices_->push_back(i);
}
}
unsigned int i; // VC6 doesn't like for-scoped variables
for (unsigned int pri=0; pri<geo->getNumPrimitiveSets(); ++pri) {
osg::PrimitiveSet *pset = geo->getPrimitiveSet(pri);
unsigned int N = pset->getNumIndices();
switch (pset->getMode()) {
case osg::PrimitiveSet::TRIANGLES:
for (i=0; i<N; i+=3) {
compute(pset, vx, nx, tx, i, i+1, i+2);
}
break;
case osg::PrimitiveSet::QUADS:
for (i=0; i<N; i+=4) {
compute(pset, vx, nx, tx, i, i+1, i+2);
compute(pset, vx, nx, tx, i+2, i+3, i);
}
break;
case osg::PrimitiveSet::TRIANGLE_STRIP:
if (pset->getType() ==
osg::PrimitiveSet::DrawArrayLengthsPrimitiveType) {
osg::DrawArrayLengths *dal =
static_cast<osg::DrawArrayLengths *>(pset);
unsigned int j = 0;
for (osg::DrawArrayLengths::const_iterator
pi=dal->begin(); pi!=dal->end(); ++pi) {
unsigned int iN = static_cast<unsigned int>(*pi-2);
for (i=0; i<iN; ++i, ++j) {
if ((i%2) == 0) {
compute(pset, vx, nx, tx, j, j+1, j+2);
} else {
compute(pset, vx, nx, tx, j+1, j, j+2);
}
}
j += 2;
}
} else {
for (i=0; i<N-2; ++i) {
if ((i%2) == 0) {
compute(pset, vx, nx, tx, i, i+1, i+2);
} else {
compute(pset, vx, nx, tx, i+1, i, i+2);
}
}
}
break;
case osg::PrimitiveSet::TRIANGLE_FAN:
if (pset->getType() ==
osg::PrimitiveSet::DrawArrayLengthsPrimitiveType) {
osg::DrawArrayLengths *dal =
static_cast<osg::DrawArrayLengths *>(pset);
unsigned int j = 0;
for (osg::DrawArrayLengths::const_iterator
pi=dal->begin(); pi!=dal->end(); ++pi) {
unsigned int iN = static_cast<unsigned int>(*pi-2);
for (i=0; i<iN; ++i) {
compute(pset, vx, nx, tx, 0, j+1, j+2);
}
j += 2;
}
} else {
for (i=0; i<N-2; ++i) {
compute(pset, vx, nx, tx, 0, i+1, i+2);
}
}
break;
case osg::PrimitiveSet::POINTS:
case osg::PrimitiveSet::LINES:
case osg::PrimitiveSet::LINE_STRIP:
case osg::PrimitiveSet::LINE_LOOP:
break;
default: osg::notify(osg::WARN) << "Warning:
TangentSpaceGenerator: unknown primitive mode " << pset->getMode() <<
"\n";
}
}
// normalize basis vectors and force the normal vector to match
// the triangle normal's direction
unsigned int attrib_count = vx->getNumElements();
if (geo->getVertexIndices() != NULL) {
attrib_count = geo->getVertexIndices()->getNumElements();
}
for (i=0; i<attrib_count; ++i) {
osg::Vec4 &vT = (*T_)[i];
osg::Vec4 &vB = (*B_)[i];
osg::Vec4 &vN = (*N_)[i];
osg::Vec3 txN = osg::Vec3(vT.x(), vT.y(), vT.z()) ^
osg::Vec3(vB.x(), vB.y(), vB.z());
if (txN * osg::Vec3(vN.x(), vN.y(), vN.z()) >= 0) {
vN = osg::Vec4(txN, 0);
} else {
vN = osg::Vec4(-txN, 0);
}
vT.normalize();
vB.normalize();
vN.normalize();
}
/* TO-DO: if indexed, compress the attributes to have only one
* version of each (different indices for each one?) */
}
void TangentSpaceGenerator::compute(osg::PrimitiveSet *pset,
const osg::Array* vx,
const osg::Array* nx,
const osg::Array* tx,
int iA, int iB, int iC)
{
iA = pset->index(iA);
iB = pset->index(iB);
iC = pset->index(iC);
osg::Vec3 P1;
osg::Vec3 P2;
osg::Vec3 P3;
int i; // VC6 doesn't like for-scoped variables
switch (vx->getType())
{
case osg::Array::Vec2ArrayType:
for (i=0; i<2; ++i) {
P1.ptr()[i] = static_cast<const osg::Vec2Array&>(*vx)[iA].ptr()[i];
P2.ptr()[i] = static_cast<const osg::Vec2Array&>(*vx)[iB].ptr()[i];
P3.ptr()[i] = static_cast<const osg::Vec2Array&>(*vx)[iC].ptr()[i];
}
break;
case osg::Array::Vec3ArrayType:
P1 = static_cast<const osg::Vec3Array&>(*vx)[iA];
P2 = static_cast<const osg::Vec3Array&>(*vx)[iB];
P3 = static_cast<const osg::Vec3Array&>(*vx)[iC];
break;
case osg::Array::Vec4ArrayType:
for (i=0; i<3; ++i) {
P1.ptr()[i] = static_cast<const osg::Vec4Array&>(*vx)[iA].ptr()[i];
P2.ptr()[i] = static_cast<const osg::Vec4Array&>(*vx)[iB].ptr()[i];
P3.ptr()[i] = static_cast<const osg::Vec4Array&>(*vx)[iC].ptr()[i];
}
break;
default:
osg::notify(osg::WARN) << "Warning: TangentSpaceGenerator:
vertex array must be Vec2Array, Vec3Array or Vec4Array" << std::endl;
}
osg::Vec3 N1;
osg::Vec3 N2;
osg::Vec3 N3;
if(nx)
{
switch (nx->getType())
{
case osg::Array::Vec2ArrayType:
for (i=0; i<2; ++i) {
N1.ptr()[i] = static_cast<const
osg::Vec2Array&>(*nx)[iA].ptr()[i];
N2.ptr()[i] = static_cast<const
osg::Vec2Array&>(*nx)[iB].ptr()[i];
N3.ptr()[i] = static_cast<const
osg::Vec2Array&>(*nx)[iC].ptr()[i];
}
break;
case osg::Array::Vec3ArrayType:
N1 = static_cast<const osg::Vec3Array&>(*nx)[iA];
N2 = static_cast<const osg::Vec3Array&>(*nx)[iB];
N3 = static_cast<const osg::Vec3Array&>(*nx)[iC];
break;
case osg::Array::Vec4ArrayType:
for (i=0; i<3; ++i) {
N1.ptr()[i] = static_cast<const
osg::Vec4Array&>(*nx)[iA].ptr()[i];
N2.ptr()[i] = static_cast<const
osg::Vec4Array&>(*nx)[iB].ptr()[i];
N3.ptr()[i] = static_cast<const
osg::Vec4Array&>(*nx)[iC].ptr()[i];
}
break;
default:
osg::notify(osg::WARN) << "Warning: TangentSpaceGenerator:
normal array must be Vec2Array, Vec3Array or Vec4Array" << std::endl;
}
}
osg::Vec2 uv1;
osg::Vec2 uv2;
osg::Vec2 uv3;
switch (tx->getType())
{
case osg::Array::Vec2ArrayType:
uv1 = static_cast<const osg::Vec2Array&>(*tx)[iA];
uv2 = static_cast<const osg::Vec2Array&>(*tx)[iB];
uv3 = static_cast<const osg::Vec2Array&>(*tx)[iC];
break;
case osg::Array::Vec3ArrayType:
for (i=0; i<2; ++i) {
uv1.ptr()[i] = static_cast<const osg::Vec3Array&>(*tx)[iA].ptr()[i];
uv2.ptr()[i] = static_cast<const osg::Vec3Array&>(*tx)[iB].ptr()[i];
uv3.ptr()[i] = static_cast<const osg::Vec3Array&>(*tx)[iC].ptr()[i];
}
break;
case osg::Array::Vec4ArrayType:
for (i=0; i<2; ++i) {
uv1.ptr()[i] = static_cast<const osg::Vec4Array&>(*tx)[iA].ptr()[i];
uv2.ptr()[i] = static_cast<const osg::Vec4Array&>(*tx)[iB].ptr()[i];
uv3.ptr()[i] = static_cast<const osg::Vec4Array&>(*tx)[iC].ptr()[i];
}
break;
default:
osg::notify(osg::WARN) << "Warning: TangentSpaceGenerator:
texture coord array must be Vec2Array, Vec3Array or Vec4Array" <<
std::endl;
}
if(nx){
osg::Vec3 V, T1, T2, T3, B1, B2, B3;
V = osg::Vec3(P2.x() - P1.x(), uv2.x() - uv1.x(), uv2.y() - uv1.y()) ^
osg::Vec3(P3.x() - P1.x(), uv3.x() - uv1.x(), uv3.y() - uv1.y());
if (V.x() != 0) {
V.normalize();
T1.x() += -V.y() / V.x();
B1.x() += -V.z() / V.x();
T2.x() += -V.y() / V.x();
B2.x() += -V.z() / V.x();
T3.x() += -V.y() / V.x();
B3.x() += -V.z() / V.x();
}
V = osg::Vec3(P2.y() - P1.y(), uv2.x() - uv1.x(), uv2.y() - uv1.y()) ^
osg::Vec3(P3.y() - P1.y(), uv3.x() - uv1.x(), uv3.y() - uv1.y());
if (V.x() != 0) {
V.normalize();
T1.y() += -V.y() / V.x();
B1.y() += -V.z() / V.x();
T2.y() += -V.y() / V.x();
B2.y() += -V.z() / V.x();
T3.y() += -V.y() / V.x();
B3.y() += -V.z() / V.x();
}
V = osg::Vec3(P2.z() - P1.z(), uv2.x() - uv1.x(), uv2.y() - uv1.y()) ^
osg::Vec3(P3.z() - P1.z(), uv3.x() - uv1.x(), uv3.y() - uv1.y());
if (V.x() != 0) {
V.normalize();
T1.z() += -V.y() / V.x();
B1.z() += -V.z() / V.x();
T2.z() += -V.y() / V.x();
B2.z() += -V.z() / V.x();
T3.z() += -V.y() / V.x();
B3.z() += -V.z() / V.x();
}
osg::Vec3 tempvec;
tempvec = N1 ^ T1;
(*T_)[iA] = osg::Vec4(tempvec ^ N1, 0);
tempvec = B1 ^ N1;
(*B_)[iA] = osg::Vec4(N1 ^ tempvec, 0);
tempvec = N2 ^ T2;
(*T_)[iB] = osg::Vec4(tempvec ^ N2, 0);
tempvec = B2 ^ N2;
(*B_)[iB] = osg::Vec4(N2 ^ tempvec, 0);
tempvec = N3 ^ T3;
(*T_)[iC] = osg::Vec4(tempvec ^ N3, 0);
tempvec = B3 ^ N3;
(*B_)[iC] = osg::Vec4(N3 ^ tempvec, 0);
(*N_)[iA] += osg::Vec4(N1, 0);
(*N_)[iB] += osg::Vec4(N2, 0);
(*N_)[iC] += osg::Vec4(N3, 0);
}
else{
osg::Vec3 face_normal = (P2 - P1) ^ (P3 - P1);
osg::Vec3 V;
V = osg::Vec3(P2.x() - P1.x(), uv2.x() - uv1.x(), uv2.y() - uv1.y()) ^
osg::Vec3(P3.x() - P1.x(), uv3.x() - uv1.x(), uv3.y() - uv1.y());
if (V.x() != 0) {
V.normalize();
float inv_x = 1.0f/V.x();
(*T_)[iA].x() += -V.y() *inv_x;
(*B_)[iA].x() += -V.z()*inv_x;
(*T_)[iB].x() += -V.y() *inv_x;
(*B_)[iB].x() += -V.z() *inv_x;
(*T_)[iC].x() += -V.y() *inv_x;
(*B_)[iC].x() += -V.z() *inv_x;
}
V = osg::Vec3(P2.y() - P1.y(), uv2.x() - uv1.x(), uv2.y() - uv1.y()) ^
osg::Vec3(P3.y() - P1.y(), uv3.x() - uv1.x(), uv3.y() - uv1.y());
if (V.x() != 0) {
V.normalize();
float inv_x = V.x();
(*T_)[iA].y() += -V.y() *inv_x;
(*B_)[iA].y() += -V.z() *inv_x;
(*T_)[iB].y() += -V.y() *inv_x;
(*B_)[iB].y() += -V.z() / inv_x;
(*T_)[iC].y() += -V.y() / inv_x;
(*B_)[iC].y() += -V.z() / inv_x;
}
V = osg::Vec3(P2.z() - P1.z(), uv2.x() - uv1.x(), uv2.y() - uv1.y()) ^
osg::Vec3(P3.z() - P1.z(), uv3.x() - uv1.x(), uv3.y() - uv1.y());
if (V.x() != 0) {
V.normalize();
float inv_x = 1.0f/V.x();
(*T_)[iA].z() += -V.y() *inv_x;
(*B_)[iA].z() += -V.z() *inv_x;
(*T_)[iB].z() += -V.y() *inv_x;
(*B_)[iB].z() += -V.z() *inv_x;
(*T_)[iC].z() += -V.y() *inv_x;
(*B_)[iC].z() += -V.z() *inv_x;
}
(*N_)[iA] += osg::Vec4(face_normal, 0);
(*N_)[iB] += osg::Vec4(face_normal, 0);
(*N_)[iC] += osg::Vec4(face_normal, 0);
}
}
--
________________________________________________________________
Anders Backman Email: [EMAIL PROTECTED]
HPC2N/VRlab Phone: +46 (0)90-786 9936
Umea university Cellular: +46 (0)70-392 64 67
S-901 87 UMEA SWEDEN Fax: +46 90-786 6126
http://www.cs.umu.se/~andersb
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