Structure for parameterizing surfaces. More...
Data Fields | |
A3DUns16 | m_usStructSize |
A3DDomainData | m_sUVDomain |
A3DBool | m_bSwapUV |
A3DDouble | m_dUCoeffA |
A3DDouble | m_dVCoeffA |
A3DDouble | m_dUCoeffB |
A3DDouble | m_dVCoeffB |
Structure for parameterizing surfaces.
This structure is used in surface definitions (see Surfaces Module). Its members specify a trimming domain (2-dimensional range) and parameterization settings.
It describes a surface reparameterization regarding the implicit parameterization that corresponds to its canonical form. Here are some important points:
Here is the evaluation formula for a given parameterization setting:
if (swap_uv) { implicit_param.u = parameterization_on_u_coeff_a * param.u + parameterization_on_u_coeff_b implicit_param.v = parameterization_on_v_coeff_a * param.v + parameterization_on_v_coeff_b } else { implicit_param.u = parameterization_on_v_coeff_a * param.v + parameterization_on_v_coeff_b implicit_param.v = parameterization_on_u_coeff_a * param.u + parameterization_on_u_coeff_b }
To ensure that implicit_param.u(min) < implicit_param.v(min)
and implicit_param.u(max) < implicit_param.v(max)
, you must specify parameterization values.
This example shows the settings to reparameterize a cylinder of 25mm height, having an implicit parameterization of 2 PI radian in u and height in v, to a domain of (0,0) and (1,1):
And this example shows the member settings to retain the implicit parameterization (reparameterization is unnecessary):
A3DUns16 A3DUVParameterizationData::m_usStructSize |
Reserved; must be initialized by A3D_INITIALIZE_DATA.
A3DDomainData A3DUVParameterizationData::m_sUVDomain |
Definition domain.
A3DBool A3DUVParameterizationData::m_bSwapUV |
Need to swap U and V coordinates.
A3DDouble A3DUVParameterizationData::m_dUCoeffA |
Coefficient for reparameterization along u vector.
A3DDouble A3DUVParameterizationData::m_dVCoeffA |
Coefficient for reparameterization along v vector.
A3DDouble A3DUVParameterizationData::m_dUCoeffB |
Coefficient for reparameterization along u vector.
A3DDouble A3DUVParameterizationData::m_dVCoeffB |
Coefficient for reparameterization along v vector.