Synopsis

PDX_MSGT igeo_ProjectPointSurfaceGrid(long option, MDA_PTR db_ptr_srf, MDA_PTR *gdx_db_ptr_grid, MTH_3DPNT point, double u0, double v0, int max_iters, MTH_3DPNT proj_point, double *u1, double *v1)

Purpose

Project a point to an IGES surface using a GDX rectangular surface mesh grid

Description

Projects a model space point to an IGES surface using a GDX rectangular surface mesh grid. If the u0 and/or v0 values are negative, then a global search is made in the rectangular surface mesh grid to try to find an initial starting parameter values, otherwise the u0 and v0 values are assumed to be initial starting parameter values to use for projection. If the GDX rectangular surface mesh grid database pointer gdx_db_ptr_grid is MDA_NULL_PTR then the rectangular surface mesh grid is created in the IGES->GDX model. Using the GDX rectangular surface grid for point projection can significantly improve performance. The application should delete the GDX rectangular surface grid entity after all projection are completed (See gdx_DeleteEntity)

The max_iters value is the maximium iterations made if the projection does not converge to PNT_PROJ_TOL.

The surface must be a valid IGES surface definition.

Input

option

IGEO_NOSETERROR

Do not set the IGEO_NOCONVERGE error

db_ptr_srf

The database pointer for the IGES surface

gdx_db_ptr_grid

The database pointer for the GDX rectangular surface mesh grid or MDA_NULL_PTR

point

The model space point to project

u0

The initial surface U parameter value(0.0 to 1.0) or < 0.0 if the value should not be used

v0

The initial surface V parameter value(0.0 to 1.0) or < 0.0 if the value should not be used

max_iters

The maximium iterations for convergence

Output

gdx_db_ptr_grid

The created GDX rectangular surface mesh grid if originally MDA_NULL_PTR

proj_point

The model space point on the surface

u1

The U parameter value of the point on the surface

v1

The V parameter value of the point on the surface

Tolerances

      PNT_PROJ_TOL
      MODEL_SPACE_PNT_TOL
      ANGLE_TOL
      ZERO_TOL
      .fi

Return

      IGEO_NOERR
      IGEO_NOCONVERGE
      Low level error return
      .fi