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# Tangent Space compute fail

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Now I'm implementing bump(normal) mapping in my program, but there is a fail: http://img51.imageshack.us/img51/8934/tangent2.jpg
You can see triangles on surface..

Can you see my function to compute tangent space, i can't find fail

l[b]andScape.verts [/b]- vertex mass landScape.verts[0] = x of first vert, landScape.verts[1] = y of first vert, landScape.verts[2] = z of frist vert and etc.
[b]landScape.normals[/b] - same for normals,
[b]landScape.texCoord[/b] - same for texture coords, but not xyz, only UV;

[source lang="cpp"]void GLW::computeLandScapeTBN() {
QVector3D p1, p2, p3;
QVector3D vec1, vec2;
QVector3D tangent;
QVector3D normal;
QVector3D binormal;
QVector3D tangentOrth;
float u1, u2, u3, v1, v2, v3;
float divider;
float NdotT;
float NdotN;

bool rightHanded;

for (int i = 0, k = 0; i < landScape.verts.size(); i += 9, k += 6) {
u1 = landScape.texCoord[k];
v1 = landScape.texCoord[k+1];
u2 = landScape.texCoord[k+2];
v2 = landScape.texCoord[k+3];
u3 = landScape.texCoord[k+4];
v3 = landScape.texCoord[k+5];

p1.setX(landScape.verts[i]), p1.setY(landScape.verts[i+1]), p1.setZ(landScape.verts[i+2]);
p2.setX(landScape.verts[i+3]), p2.setY(landScape.verts[i+4]), p2.setZ(landScape.verts[i+5]);
p3.setX(landScape.verts[i+6]), p3.setY(landScape.verts[i+7]), p3.setZ(landScape.verts[i+8]);

vec1 = QVector3D((p2.x()-p1.x())*(v3-v1), (p2.y()-p1.y())*(v3-v1), (p2.z()-p1.z())*(v3-v1));
vec2 = QVector3D((p3.x()-p1.x())*(v2-v1), (p3.y()-p1.y())*(v2-v1), (p3.z()-p1.z())*(v2-v1));

divider = (u2-u1)*(v3-v1) - (v2-v1)*(u3-u1);

tangent = QVector3D((vec1.x()-vec2.x())/divider,
(vec1.y()-vec2.y())/divider,
(vec1.z()-vec2.z())/divider);

normal = QVector3D(landScape.normals[i], landScape.normals[i+1], landScape.normals[i+2]);
NdotT = normal.x()*tangent.x() + normal.y()*tangent.y() + normal.z()*tangent.z();
NdotN = normal.x()*normal.x() + normal.y()*normal.y() + normal.z()*normal.z();
tangentOrth = QVector3D(tangent.x() - normal.x()*NdotT/NdotN, tangent.y() - normal.y()*NdotT/NdotN, tangent.z() - normal.z()*NdotT/NdotN);
tangentOrth.normalize();
binormal = QVector3D::crossProduct(normal, tangentOrth);
rightHanded = QVector3D::dotProduct(QVector3D::crossProduct(tangentOrth, binormal), normal) >= 0;
if(!rightHanded) binormal = QVector3D(binormal.x()*(-1), binormal.y()*(-1), binormal.z()*(-1));
landScape.tangents.push_back(tangentOrth.x()), landScape.tangents.push_back(tangentOrth.y()), landScape.tangents.push_back(tangentOrth.z());
landScape.binormals.push_back(binormal.x()), landScape.binormals.push_back(binormal.y()), landScape.binormals.push_back(binormal.z());

normal = QVector3D(landScape.normals[i+3], landScape.normals[i+4], landScape.normals[i+5]);
NdotT = normal.x()*tangent.x() + normal.y()*tangent.y() + normal.z()*tangent.z();
NdotN = normal.x()*normal.x() + normal.y()*normal.y() + normal.z()*normal.z();
tangentOrth = QVector3D(tangent.x() - normal.x()*NdotT/NdotN, tangent.y() - normal.y()*NdotT/NdotN, tangent.z() - normal.z()*NdotT/NdotN);
tangentOrth.normalize();
binormal = QVector3D::crossProduct(normal, tangentOrth);
rightHanded = QVector3D::dotProduct(QVector3D::crossProduct(tangentOrth, binormal), normal) >= 0;
if(!rightHanded) binormal = QVector3D(binormal.x()*(-1), binormal.y()*(-1), binormal.z()*(-1));
landScape.tangents.push_back(tangentOrth.x()), landScape.tangents.push_back(tangentOrth.y()), landScape.tangents.push_back(tangentOrth.z());
landScape.binormals.push_back(binormal.x()), landScape.binormals.push_back(binormal.y()), landScape.binormals.push_back(binormal.z());

normal = QVector3D(landScape.normals[i+6], landScape.normals[i+7], landScape.normals[i+8]);
NdotT = normal.x()*tangent.x() + normal.y()*tangent.y() + normal.z()*tangent.z();
NdotN = normal.x()*normal.x() + normal.y()*normal.y() + normal.z()*normal.z();
tangentOrth = QVector3D(tangent.x() - normal.x()*NdotT/NdotN, tangent.y() - normal.y()*NdotT/NdotN, tangent.z() - normal.z()*NdotT/NdotN);
tangentOrth.normalize();
binormal = QVector3D::crossProduct(normal, tangentOrth);
rightHanded = QVector3D::dotProduct(QVector3D::crossProduct(tangentOrth, binormal), normal) >= 0;
if(!rightHanded) binormal = QVector3D(binormal.x()*(-1), binormal.y()*(-1), binormal.z()*(-1));
landScape.tangents.push_back(tangentOrth.x()), landScape.tangents.push_back(tangentOrth.y()), landScape.tangents.push_back(tangentOrth.z());
landScape.binormals.push_back(binormal.x()), landScape.binormals.push_back(binormal.y()), landScape.binormals.push_back(binormal.z());
}
}[/source]
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