Persistence of Vision Raytracer Version 1.0 Quick Reference ------------------------------- By Chris Young This is a formal grammar definition of the POV-Ray scene description language. It is based on PARSE.C and TOKENIZE.C from version 1.0 of POV-Ray. See POVRAY.DOC for in-depth description of the program and language The POV-Ray language is used to describe something called a FRAME. Everything needed to render that image is stored in a text file describing that FRAME. Also note, #include "filename.inc" can appear anywhere in the text to include text from another file. The parser will behave as if all the text from filename.inc were inserted at that point in the file. Note that the use of "#" is currently optional, but recommended for readability when using include and declare for readability. This will be mandatory in future versions. Any text following "//" to the end of the line is ignored as comments. Furthermore text between "/*" and "*/" is considered a comment. /* */ comments can be nested. In the notation used below in general a single character in quotes is that literal character. All lower case words are also literal and they are reserved keywords. Upper case words denote language constructs. An ellipsis denotes one or more. Square brackets denote optional. A bar | denotes a choice of item or items. A scroll bracket is a literal "{" or "}" but the quotes have been omitted for clarity. For example: ITEM one occurrence of ITEM ITEM... one or more occurrences of ITEM [ITEM] zero or one occurrence of ITEM [ITEM...] zero or more occurrences of ITEM ITEM_1 | ITEM_2 one occurrence of either ITEM_1 or ITEM_2 NOTE: STRING is defined as a string of characters in quotes IDENTIFIER is an alphabetic character followed by one or more alphanumerics or underscores ITEM_IDENTIFIER is an IDENTIFIER of type ITEM Leave questions/comments to Chris Young CIS:[76702,1655] -------------------------------------------------------------- DIGIT = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" POINT = "." EXP = "e" | "E" SIGN = "+" | "-" FLOAT_CONST = [DIGIT...] [POINT] DIGIT... [EXP [SIGN] DIGIT...] FLOAT = [SIGN] FLOAT_CONST | [SIGN] FLOAT_IDENTIFIER COLOR_ITEM = red FLOAT | green FLOAT | blue FLOAT | alpha FLOAT | COLOR_IDENTIFIER COLOR_SPEC = color [COLOR_ITEM...] Note:"color" and "colour" can be used interchangeably everywhere. COLOR_MAP_ENTRY = "[" FLOAT FLOAT COLOR_SPEC COLOR_SPEC "]" COLOR_MAP = color_map { [COLOR_MAP_ENTRY...] } VECTOR = "<" FLOAT FLOAT FLOAT ">" MAP_PREFIX = FLOAT | VECTOR MAP_FILE = iff STRING | tga STRING | gif STRING | dump STRING IMAGE_ATTRIB= once | interpolate FLOAT | map_type FLOAT | use_color | use_index | alpha all FLOAT | alpha FLOAT FLOAT BUMP_ATTRIB = once | interpolate FLOAT | map_type FLOAT | bump_size FLOAT | use_color | use_index MATER_ATTRIB= once | interpolate FLOAT | map_type FLOAT | TEXTURE TEXTURE_ITEM= TEXTURE_IDENTIFIER | FLOAT | once | turbulence FLOAT | octaves FLOAT | brick color COLOR_SPEC color COLOR_SPEC | mortar FLOAT | checker [COLOR_SPEC [COLOR_SPEC]] | tiles { [TEXTURE] tile2 [TEXTURE] } | bozo | marble | wood | spotted | agate | granite | metallic | onion | leopard | painted1 | painted2 | painted3 | gradient VECTOR | ambient FLOAT | brilliance FLOAT | roughness FLOAT | phong_size FLOAT | diffuse FLOAT | specular FLOAT | phong FLOAT | ior FLOAT | refraction FLOAT | reflection FLOAT | waves FLOAT [phase FLOAT] | frequency FLOAT | phase FLOAT | ripples FLOAT | wrinkles FLOAT | bumps FLOAT | dents FLOAT | translate VECTOR | rotate VECTOR | scale VECTOR | COLOR_SPEC | COLOR_MAP | image_map { [MAP_PREFIX...] MAP_FILE [IMAGE_ATTRIB...] } | bump_map { [MAP_PREFIX...] MAP_FILE [BUMP_ATTRIB...] } | material_map { [MAP_PREFIX...] MAP_FILE [MATER_ATTRIB...] } TEXTURE = texture { [TEXTURE_ITEMS...] } USUAL_MODS = translate VECTOR | rotate VECTOR | scale VECTOR | inverse | TEXTURE | COLOR_SPEC SPHERE_BODY = VECTOR FLOAT | SPHERE_IDENTIFIER SPHERE = sphere { SPHERE_BODY [USUAL_MODS...] } PLANE_BODY = VECTOR FLOAT | PLANE_IDENTIFIER PLANE = plane { PLANE_IDENTIFIER [USUAL_MODS...] } HFILE_TYPE = gif STRING | pot STRING | tga STRING | HFIELD_IDENTIFIER HFIELD_MODS = USUAL_MODS | water_level FLOAT HFIELD = height_field { HFILE_TYPE [HFIELD_MODS...] } TRI_BODY = VECTOR VECTOR VECTOR | TRIANGLE_IDENTIFIER TRIANGLE = triangle { TRI_BODY [USUAL_MODS...] } SMO_TRI_BODY= VECTOR VECTOR VECTOR VECTOR VECTOR VECTOR | SMOOTH_TRIANGLE_IDENTIFIER SMO_TRIANGLE= smooth_triangle { SMO_TRI_BODY [USUAL_MODS...] } QUAD_BODY = VECTOR VECTOR VECTOR FLOAT | QUADRIC_IDENTIFIER QUADRIC = quadric { QUAD_BODY [USUAL_MODS...] } Note a POLY_N has M terms where M = (N+1)*(N+2)*(N+3)/6 POLY_N = "<" float_1 float_2... FLOAT_M ">" | POLY_IDENTIFIER POLY_MODS = USUAL_MODS | sturm CUBIC = cubic { POLY_3 [POLY_MODS...] } QUARTIC = quartic { POLY_4 [POLY_MODS...] } POLY = poly { FLOAT POLY_N [POLY_MODS...] } BI_BODY = FLOAT [FLOAT] FLOAT FLOAT VECTOR_1 VECTOR_2... VECTOR_16 | BICUBIC_IDENTIFIER BICUBIC = bicubic_patch { BI_BODY [USUAL_MODS...] } BOX_BODY = VECTOR VECTOR | BOX_IDENTIFIER BOX = box { BOX_BODY [USUAL_MODS...] } BLOB_ITEM = threshold FLOAT | component FLOAT FLOAT VECTOR BLOB_BODY = [BLOB_ITEM...] | BLOB_IDENTIFIER BLOB = blob { BLOB_BODY [POLY_MODS...] } LIGHT_MODS = translate VECTOR | rotate VECTOR | scale VECTOR | point_at VECTOR | tightness FLOAT | radius FLOAT | falloff FLOAT | spotlight | COLOR_SPEC LIGHT_BODY = VECTOR | LIGHT_IDENTIFIER LIGHT_SOURCE= light_source { LIGHT_BODY [LIGHT_MODS..] } SHAPE = LIGHT_SOURCE | SPHERE | PLANE | TRIANGLE | SMO_TRIANGLE | QUADRIC | HFIELD | CUBIC | QUARTIC | POLY | BICUBIC | BOX | BLOB | UNION | INTERSECTION | DIFFERENCE CSG_BODY = SHAPE | CSG_IDENTIFIER CSG_MODS = translate VECTOR | rotate VECTOR | scale VECTOR | inverse INTERSECTION= intersection { [CSG_BODY...] [CSG_MODS...] } UNION = union { [CSG_BODY...] [CSG_MODS...] } DIFFERENCE = difference { [CSG_BODY...] [CSG_MODS...] } BOUNDED_BY = bounded_by { [SHAPE...] } CLIPPED_BY = clipped_by { [SHAPE...] } OBJ_BODY = SHAPE | OBJECT_IDENTIFIER OBJ_MODS = USUAL_MODS | BOUNDED_BY | CLIPPED_BY | no_shadow OBJECT = object { OBJ_BODY [OBJ_MODS...] } COMP_MODS = CSG_MODS | BOUNDED_BY | CLIPPED_BY COMP_BODY = COMPOSITE | OBJECT | COMP_IDENTIFIER COMPOSITE = composite { COMP_BODY... [COMP_MODS...] } CAMERA_BODY = location VECTOR | direction VECTOR | up VECTOR | right VECTOR | sky VECTOR | look_at VECTOR | translate VECTOR | rotate VECTOR | scale VECTOR | CAMERA_IDENTIFIER CAMERA = camera { [CAMERA_BODY...] } FOG_BODY = COLOR_SPEC | FLOAT FOG = fog { [FOG_BODY...] } DECLARE_BODY= OBJECT | SHAPE | COMPOSITE | TEXTURE... | COLOR_SPEC | CAMERA | VECTOR | FLOAT DECLARE = declare IDENTIFIER "=" DECLARE_BODY DEFAULT = default { TEXTURE } FRAME_ITEM = FOG | DEFAULT | OBJECT | COMPOSITE | DECLARE | CAMERA | max_trace_level FLOAT FRAME = FRAME_ITEM...