C – How to achieve smooth tangent space?

 vector1 = vertex2.coords-vertex1.coords; 
 vector2 = vertex3.coords-vertex1.coords;

 tuVector = vertex2.texcoords-vertex1.texcoords;
 tvVector = vertex3. texcoords-vertex1.texcoords;

 float den = 1.0f / (tuVector.x * tvVector.y-tuVector.y * tvVector.x);

 tangent.x = (tvVector.y * vector1.x-tvVector.x * vector2.x) * den;
 tangent.y = (tvVector.y * vector1.y-tvVector.x * vector2.y) * den;
 tangent.z = (tvVector.y * vector1.z-tvVector.x * vector2.z) * den;

 binormal.x = (tuVector.x * vector2.x-tuVector.y * vector1.x) * den;
 binormal.y = (tuVector.x * vector2.y-tuVector.y * vector1.y) * den;
 binormal.z = (tuVector.x * vector2 .z-tuVecto ry * vector1.z) * den;

 D3DXVec3Normalize(&tangent, &tangent);
 D3DXVec3Normalize(&binormal, &binormal);

 D3DXVec3Cross(&normal, &tangent, &binormal ); 
 D3DXVec3Normalize(&normal, &normal);

double N[3]; //normal
int cnt;

N={0.0,0.0,0.0}
cnt=0;

N/=cnt; // N = average normal from all vertex-neighbour faces

I am trying to add the bump map function to mine Application, but I am getting a very multi-faceted model:

It happened because I calculated the tangent on each face, normal and normal, and completely ignored me from the model file The obtained normal.

Calculate the current two sides of the triangle and the texture space vector to obtain the tangent and the subnormal, and then use it to calculate the normal through the cross product. Once the model is loaded, all this is in It is done on the CPU, and then the value is stored as part of the model geometry.

vector1 = vertex2.coords-vertex1.coords; 
 vector2 = vertex3.coords-vertex1. coords;

 tuVector = vertex2.texcoords-vertex1.texcoords;
 tvVector = vertex3.texcoords-vertex1.texc oords;

 float den = 1.0f / (tuVector.x * tvVector.y-tuVector.y * tvVector.x);

 tangent.x = (tvVector.y * vector1.x-tvVector.x * vector2.x) * den;
 tangent.y = (tvVector.y * vector1.y-tvVector.x * vector2.y) * den;
 tangent. z = (tvVector.y * vector1.z-tvVector.x * vector2.z) * den;

 binormal.x = (tuVector.x * vector2.x-tuVector.y * vector1.x ) * den;
 binormal.y = (tuVector.x * vector2.y-tuVector.y * vector1.y) * den;
 binormal.z = (tuVector.x * vector2.z-tuVector .y * vector1.z) * den;

 D3DXVec3Normalize(&tangent, &tangent);
 D3DXVec3Normalize(&binormal, &binormal);

 D3DXVec3Cross(&normal, &tangent, &binormal); 
 D3DXVec3Normalize(&normal, &normal);

Is there a way to calculate these values ​​on a per-vertex basis, maybe use the normals provided by the model or smooth them in some way, So that the model will not be faceted?

For smooth surfaces (no edges), I do this:

>Create space for each vertex

p>

double N[3]; //normal
int cnt;

>each vertex init

N={0.0,0.0,0.0}
cnt=0;

>Calculate normal by face

Normal must be standardized length = 1.0 !!! This Normal is added to all vertices used in the face, and cnt is added to all vertices used in the face
>Every vertex is normalized

N/=cnt; / / N = average normal from all vertex-neighbour faces

Note the cnt of unused vertices = 0 (divide by zero)
>Each vertex N contains the normal you want

Now, calculate the T and B vectors of the TBN matrix (each vertex) like now.
>The output image is smooth

My earth preview (atmospheric scattering, bump mapping, etc.) is here

I hope I can help you