This section defines the 3D view of a raytracer scene with the sistem VRC (3D viewing-reference coordinate).
To define exactly all the attributes you can see in [1].
section_view = { . vcr . { [ def_vrp | def_prp | def_vup | def_vpn | def_umax | def_umin | def_vmax |
def_vmin | def_type | def_f | def_b | def_fon | def_bon ] } . }
def_vrp = vrp . point . ;
def_prp = prp . point . ;
def_vup = vup . point . ;
def_vpn = vpn . point . ;
def_umax = umax . number_real . ;
def_umin = umin . number_real . ;
def_vmax = vmax . number_real . ;
def_vmin = vmin . number_real . ;
def_type = type . number_integer . ;
def_f = f . number_real . ;
def_b = b . number_real . ;
def_fon = fon . number_integer . ;
def_bon = bon . number_integer . ;
section_view
complete definition of the view 3D.
def_vrp
definition of the view reference point ( VRP ) , the origin of VCR system.
With the VPN defines the plane of the image.
def_prp
definition of the projection reference point ( PRP ).
def_vup
definition of the view up vector ( VUP ), which limit the v axis on the image plane.
def_vpn
definition of the view-plane normal ( VPN ), is the n axis of the VRC system.
With the VPN defines the plane of the image.
def_umax
def_umin
def_vmax
def_vmin
definition of limitis of the image window on the view plane.
def_type
Type of projection.
1 means perspective projection , while 0 means parallel projection.
def_f
the front distance ( F ). This parameter will be ignored.
def_b
the la back distance ( B ). This parameter will be ignored.
def_fon
This parameter will be ignored.
def_bon
This parameter will be ignored.