Is 'pHit' ever true? What is the HRESULT of D3DXIntersect()?

Have you checked the validity of the data behind two Lock()-pointers? If you assign the indices to a WORD, the buffer should be created as a 16 bit buffer.

Also, I don't see why you would test all faces individually once D3DXIntersect() has determined an intersection.

Is 'pHit' ever true? What is the HRESULT of D3DXIntersect()?

I'm getting intersected triangle in (v0, v1, v2) but it's invalid, D3DXIntersect() HRESULT is S_OK.

Have you checked the validity of the data behind two Lock()-pointers? If you assign the indices to a WORD, the buffer should be created as a 16 bit buffer.

I tried using byte* instead of WORD*, same problem.

Also, I don't see why you would test all faces individually once D3DXIntersect() has determined an intersection.

I use break; after working on the intersection:

if ( D3DXIntersectTri(&v0, &v1, &v2, &rayFrom, &rayTo, &pU, &pV, &pDist) )
{
     // Process intersection...
     break;
}

@Postie:

First, I use bullet physics raycasting to check for intersection, then I use D3DXIntersect() to get the intersected triangle, rayFrom and rayTo are D3DXVECTOR3 that I use with bullet physics raycasting.

I changed the code to something like this:

LPD3DXMESH pMesh = GetMesh();
pMesh->CloneMeshFVF( D3DXMESH_MANAGED, pMesh->GetFVF(), d3ddev, &pMesh );

WORD* pIndices;
D3DVERTEX* pVertices;
pMesh->LockVertexBuffer(D3DLOCK_READONLY, (void**)&pVertices);
pMesh->LockIndexBuffer(D3DLOCK_READONLY, (void**)&pIndices);

BOOL pHit;
DWORD pFaceIndex;
FLOAT pU, pV, pDist;
HRESULT hr = D3DXIntersect(pMesh, &rayFrom, &rayTo, &pHit, &pFaceIndex, &pU, &pV, &pDist, NULL, NULL);
assert(hr == S_OK);
if (pHit)
{
    D3DXVECTOR3 v0 = pVertices[pIndices[3 * pFaceIndex + 0]].p;
    D3DXVECTOR3 v1 = pVertices[pIndices[3 * pFaceIndex + 1]].p;
    D3DXVECTOR3 v2 = pVertices[pIndices[3 * pFaceIndex + 2]].p;
}

pMesh->UnlockVertexBuffer();
pMesh->UnlockIndexBuffer();

Anything wrong with the above code?

UP! Any help would be appreciated, I'm still having this problem.

@L. Spiro:

So that means I have to pass (rayTo - rayFrom) as a direction.

I tried:

HRESULT hr = D3DXIntersect(pMesh, &rayFrom, &(rayTo - rayFrom), &pHit, &pFaceIndex, &pU, &pV, &pDist, NULL, NULL);
assert(hr == S_OK);
if (pHit)
{
    D3DXVECTOR3 v0 = pVertices[pIndices[3 * pFaceIndex + 0]].p;
    D3DXVECTOR3 v1 = pVertices[pIndices[3 * pFaceIndex + 1]].p;
    D3DXVECTOR3 v2 = pVertices[pIndices[3 * pFaceIndex + 2]].p;
}

Still not getting a valid intersected triangle.

When I switch to Wirefire mode, I notice that I'm getting a valid intersected triangle for the terrain ONLY, but none of the other meshes are getting a valid intersected triangle.

Here is the code that I tried:

// Get ray direction
D3DXVECTOR3 direction = rayTo - rayFrom;
D3DXVec3Normalize(&direction, &direction);

// Inverse matrix
D3DXMATRIX matWorld = mesh->worldMatrix();
D3DXMATRIX matInverse;
D3DXMatrixInverse(&matInverse, NULL, &matWorld);

D3DXVECTOR3 modelRayOrigin, modelRayDir;
D3DXVec3TransformCoord(&modelRayOrigin, &hits.origin, &matInverse);
D3DXVec3TransformNormal(&modelRayDir, &direction, &matInverse);

hr = D3DXIntersect(pMesh, &modelRayOrigin, &modelRayDir, &pHit, &pFaceIndex, &pU, &pV, &pDist, NULL, NULL);
assert(hr == S_OK);