Method cameraLookAlong

source/MRViewer/MRViewportCamera.cpp:793–811

}

void Viewport::cameraLookAlong( const Vector3f& newDir, const Vector3f& up )
{
    assert( std::abs( dot( newDir.normalized(), up.normalized() ) ) < 1e-6f );

    Vector3f lookDir = cameraCenter - cameraEye;
    auto rotLook = Matrix3f::rotation( newDir, lookDir );

    auto upVec = rotLook.inverse() * cameraUp;
    float sign = 1.0f;
    if ( dot( cross( up, upVec ), newDir ) < 0.0f )
        sign = -1.0f;

    auto rotUp = Matrix3f::rotation( newDir, sign * angle( up, upVec ) );

    params_.cameraTrackballAngle = rotLook;
    params_.cameraTrackballAngle = params_.cameraTrackballAngle * Quaternionf( rotUp );

    needRedraw_ = true;
}

void Viewport::cameraRotateAround( const Line3f& axis, float angle )
{