void ExpMapGenerator::SetSmoothNormal( ExpMapParticle * pParticle, ExpMapParticle::ListEntry * pNbrs, bool bEnable )
{
if ( bEnable && pParticle->m_bNormalSmoothed )
return;
else if ( !bEnable && !pParticle->m_bNormalSmoothed)
return;
Wml::Vector3f vPos, vNorm, vNbrPos, vNbrNorm;
if ( bEnable ) {
float fWeightSum = 0.0f;
Wml::Vector3f vAverage = Wml::Vector3f::ZERO;
GetMesh()->GetVertex( pParticle->VertexID(), vPos, &vNorm);
ExpMapParticle::ListEntry * pCur = pNbrs;
while ( pCur != NULL ) {
IMesh::VertexID nID = pCur->pParticle->VertexID();
Wml::Vector3f vNbrPos, vNbrNorm;
GetMesh()->GetVertex( pCur->pParticle->VertexID(), vNbrPos, &vNbrNorm);
float fWeight = 1.0f / ( (vPos - vNbrPos).Length() + (0.0001f*m_fMaxEdgeLength) );
vAverage += fWeight * vNbrNorm;
fWeightSum += fWeight;
pCur = pCur->pNext;
}
vAverage /= fWeightSum;
vAverage.Normalize();
pParticle->Normal() = vAverage;
} else {
GetMesh()->GetNormal( pParticle->VertexID(), pParticle->Normal() );
}
pParticle->WorldFrame() = Frame3f( pParticle->Position(), pParticle->Normal() );
pParticle->m_bNormalSmoothed = bEnable;
}
void ExpMapGenerator::PrecomputePropagationData( ExpMapParticle * pCenterParticle,
ExtPlane3f & vTangentPlane,
Frame3f & vCenterWorldFrame,
Wml::Matrix2f & matFrameRotate )
{
// compute surface-tangent plane at particle
Wml::Vector3f vNormal( pCenterParticle->Normal() );
// compute plane at this point
vTangentPlane = ExtPlane3f( vNormal, pCenterParticle->Position() );
// compute 3D frame at center point
//vCenterWorldFrame = Frame3f( pCenterParticle->Position(), vNormal );
vCenterWorldFrame = pCenterParticle->WorldFrame();
// rotate seed world frame Z into this particle's Z
Frame3f seedWorldFrame( m_pSeedParticle->WorldFrame() );
seedWorldFrame.AlignZAxis( vCenterWorldFrame );
// compute cos(angle) between axis
Wml::Vector3f vCenterAxisX( vCenterWorldFrame.Axis( Frame3f::AxisX ) );
Wml::Vector3f vSeedAxisX( seedWorldFrame.Axis( Frame3f::AxisX ) );
float fCosTheta = vCenterAxisX.Dot(vSeedAxisX);
// compute rotated min-dist vector for this particle
float fTmp = 1 - fCosTheta*fCosTheta;
if ( fTmp < 0 ) fTmp = 0; // need to clamp so that sqrt works...
float fSinTheta = (float)sqrt(fTmp);
Wml::Vector3f vCross = vCenterAxisX.Cross(vSeedAxisX);
if ( vCross.Dot( vNormal ) < 0 ) // get the right sign...
fSinTheta = -fSinTheta;
// create transposed 2D rotation matrix
matFrameRotate = Wml::Matrix2f( fCosTheta, fSinTheta, -fSinTheta, fCosTheta );
}
Wml::Vector2f ExpMapGenerator::ComputeSurfaceVector( ExpMapParticle * pCenterParticle,
ExpMapParticle * pNbrParticle,
ExtPlane3f & vTangentPlane,
Frame3f & vCenterWorldFrame,
Wml::Matrix2f & matFrameRotate )
{
// special case...
if ( (pNbrParticle->Position() - pCenterParticle->Position()).Length() < Wml::Mathf::EPSILON )
return pCenterParticle->SurfaceVector();
// project point into plane
Wml::Vector3f vPlanePoint = vTangentPlane.RotatePointIntoPlane( pNbrParticle->Position() );
// project point into coord system of frame
vPlanePoint -= pCenterParticle->Position();
vCenterWorldFrame.ToFrameLocal(vPlanePoint);
// now we can project into surface frame simply by dropping z (which should be 0 anyway,
// since the vector lies in the plane!)
Wml::Vector2f vSurfaceFrame( vPlanePoint.X(), vPlanePoint.Y() );
// reverse vector so it points back to current particle
vSurfaceFrame *= -1.0f;
// transform local vector into coord system of initial surface reference frame
// and add accumulated surface vector
return pCenterParticle->SurfaceVector() + (matFrameRotate * vSurfaceFrame);
}
Wml::Vector3d rms::VectorCastfd( const Wml::Vector3f & vec )
{
return Wml::Vector3d( (double)vec.X(), (double)vec.Y(), (double)vec.Z() );
}
