5.2.6 Bicubic Patch

A 2-dimensional variant of cubic splines is the bicubic patch object with syntax:

BICUBIC_PATCH:
  bicubic_patch { PATCH_ITEMS [PATCH_UV_VECTORS] CONTROL_POINTS 
    [BICUBIC_PATCH_MODIFIERS] }

PATCH_ITEMS:
  type PATCH_TYPE & [u_steps INT] & [v_steps INT] 
    & [flatness FLOAT]

PATCH_TYPE:
  0 | 1

PATCH_UV_VECTORS:
  uv_vectors V2_CORNER1, V2_CORNER2, V2_CORNER3, V2_CORNER4

CONTROL_POINTS:
  16 VECTORs, optionally separated by commas.

BICUBIC_PATCH_MODIFIERS:
  [UV_MAPPING] & [OBJECT_MODIFIERS]

See also:

• [pov:6.5.2.1]Bicubic Patch
• [pov:3.4.5]Bicubic Patch Object