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greg |
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/* Copyright (c) 1990 Regents of the University of California */ |
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
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/* |
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* Convert Neutral File Format input to Radiance scene description. |
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* |
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* 12/9/90 Greg Ward |
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*/ |
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/****************************************************************** |
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Since Eric Haines wrote such excellent documentation of his |
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Neutral File Format, I am just going to reprint it here with |
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my added comments in braces {}. |
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Neutral File Format (NFF), by Eric Haines |
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Draft document #1, 10/3/88 |
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The NFF (Neutral File Format) is designed as a minimal scene description |
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language. The language was designed in order to test various rendering |
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algorithms and efficiency schemes. It is meant to describe the geometry and |
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basic surface characteristics of objects, the placement of lights, and the |
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viewing frustum for the eye. Some additional information is provided for |
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esthetic reasons (such as the color of the objects, which is not strictly |
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necessary for testing rendering algorithms). |
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Future enhancements include: circle and torus objects, spline surfaces |
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with trimming curves, directional lights, characteristics for positional |
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lights, CSG descriptions, and probably more by the time you read this. |
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Comments, suggestions, and criticisms are all welcome. |
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At present the NFF file format is used in conjunction with the SPD (Standard |
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Procedural Database) software, a package designed to create a variety of |
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databases for testing rendering schemes. The SPD package is available |
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from Netlib and via ftp from drizzle.cs.uoregon.edu. For more information |
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about SPD see "A Proposal for Standard Graphics Environments," IEEE Computer |
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Graphics and Applications, vol. 7, no. 11, November 1987, pp. 3-5. |
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By providing a minimal interface, NFF is meant to act as a simple format to |
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allow the programmer to quickly write filters to move from NFF to the |
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local file format. Presently the following entities are supported: |
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A simple perspective frustum |
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A positional (vs. directional) light source description |
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A background color description |
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A surface properties description |
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Polygon, polygonal patch, cylinder/cone, and sphere descriptions |
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Files are output as lines of text. For each entity, the first line |
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defines its type. The rest of the first line and possibly other lines |
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contain further information about the entity. Entities include: |
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"v" - viewing vectors and angles { optionally creates view file } |
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"l" - positional light location { it's there, but bad to use } |
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"b" - background color { ditto } |
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"f" - object material properties { this is flakey } |
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"c" - cone or cylinder primitive |
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"s" - sphere primitive |
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"p" - polygon primitive |
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"pp" - polygonal patch primitive { interpreted same as p for now } |
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These are explained in depth below: { see conversion routines } |
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***********************************************************************/ |
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#include <stdio.h> |
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char *viewfile = NULL; /* view parameters file */ |
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char *progname; |
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main(argc, argv) /* convert NFF file to Radiance */ |
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int argc; |
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char *argv[]; |
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{ |
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int i; |
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progname = argv[0]; |
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for (i = 1; i < argc; i++) |
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if (argc-i > 1 && !strcmp(argv[i], "-vf")) |
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viewfile = argv[++i]; |
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else |
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break; |
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if (i-argc > 1) |
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goto userr; |
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if (i-argc == 1 && freopen(argv[i], "r", stdin) == NULL) { |
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perror(argv[i]); |
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exit(1); |
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} |
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init(); |
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nff2rad(); |
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exit(0); |
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userr: |
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fprintf(stderr, "Usage: %s [-vf viewfile] [input]\n", progname); |
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exit(1); |
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} |
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init() /* spit out initial definitions */ |
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{ |
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printf("# File created by %s\n", progname); |
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printf("\nvoid light light\n"); |
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printf("0\n0\n3 1 1 1\n"); |
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printf("\nvoid plastic fill\n"); |
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printf("0\n0\n5 .5 .5 .5 0 0\n"); |
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} |
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nff2rad() /* convert NFF on stdin to Radiance on stdout */ |
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{ |
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register int c; |
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while ((c = getchar()) != EOF) |
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switch (c) { |
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case ' ': /* white space */ |
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case '\t': |
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case '\n': |
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case '\f': |
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case '\r': |
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continue; |
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case '#': /* comment */ |
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comment(); |
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break; |
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case 'v': /* view point */ |
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view(); |
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break; |
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case 'l': /* light source */ |
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light(); |
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break; |
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case 'b': /* background color */ |
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background(); |
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break; |
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case 'f': /* fill material */ |
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fill(); |
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break; |
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case 'c': /* cylinder or cone */ |
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cone(); |
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break; |
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case 's': /* sphere */ |
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sphere(); |
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break; |
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case 'p': /* polygon or patch */ |
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poly(); |
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break; |
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default: /* unknown */ |
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fprintf(stderr, "%c: unknown NFF primitive\n", c); |
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exit(1); |
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} |
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} |
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/******************************************* |
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Comment. Description: |
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"#" [ string ] |
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Format: |
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# [ string ] |
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As soon as a "#" character is detected, the rest of the line is considered |
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a comment. |
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******************/ |
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comment() |
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{ |
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register int c; |
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putchar('#'); |
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while ((c = getchar()) != EOF) { |
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putchar(c); |
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if (c == '\n') |
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break; |
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} |
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} |
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/*************************************************** |
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Viewpoint location. Description: |
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"v" |
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"from" Fx Fy Fz |
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"at" Ax Ay Az |
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"up" Ux Uy Uz |
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"angle" angle |
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"hither" hither |
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"resolution" xres yres |
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Format: |
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v |
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from %g %g %g |
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at %g %g %g |
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up %g %g %g |
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angle %g |
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hither %g |
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resolution %d %d |
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The parameters are: |
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From: the eye location in XYZ. |
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At: a position to be at the center of the image, in XYZ world |
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coordinates. A.k.a. "lookat". |
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Up: a vector defining which direction is up, as an XYZ vector. |
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Angle: in degrees, defined as from the center of top pixel row to |
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bottom pixel row and left column to right column. |
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Resolution: in pixels, in x and in y. |
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Note that no assumptions are made about normalizing the data (e.g. the |
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from-at distance does not have to be 1). Also, vectors are not |
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required to be perpendicular to each other. |
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For all databases some viewing parameters are always the same: |
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Yon is "at infinity." |
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Aspect ratio is 1.0. |
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A view entity must be defined before any objects are defined (this |
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requirement is so that NFF files can be used by hidden surface machines). |
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***************/ |
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view() |
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{ |
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static FILE *fp = NULL; |
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float from[3], at[3], up[3], angle; |
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if (scanf(" from %f %f %f", &from[0], &from[1], &from[2]) != 3) |
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goto fmterr; |
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if (scanf(" at %f %f %f", &at[0], &at[1], &at[2]) != 3) |
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goto fmterr; |
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if (scanf(" up %f %f %f", &up[0], &up[1], &up[2]) != 3) |
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goto fmterr; |
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if (scanf(" angle %f", &angle) != 1) |
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goto fmterr; |
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scanf(" hither %*f"); |
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scanf(" resolution %*d %*d"); |
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if (viewfile != NULL) { |
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if (fp == NULL && (fp = fopen(viewfile, "a")) == NULL) { |
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perror(viewfile); |
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exit(1); |
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} |
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fprintf(fp, |
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"VIEW= -vp %g %g %g -vd %g %g %g -vu %g %g %g -vh %g -vv %g\n", |
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from[0], from[1], from[2], |
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at[0]-from[0], at[1]-from[1], at[2]-from[2], |
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up[0], up[1], up[2], |
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angle, angle); |
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} |
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return; |
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fmterr: |
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fprintf(stderr, "%s: view syntax error\n", progname); |
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exit(1); |
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} |
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/******************************** |
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Positional light. A light is defined by XYZ position. Description: |
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"l" X Y Z |
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Format: |
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l %g %g %g |
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All light entities must be defined before any objects are defined (this |
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requirement is so that NFF files can be used by hidden surface machines). |
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Lights have a non-zero intensity of no particular value [this definition |
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may change soon, with the addition of an intensity and/or color]. |
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**************************/ |
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light() |
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{ |
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static int nlights = 0; |
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register int c; |
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float x, y, z; |
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if (scanf("%f %f %f", &x, &y, &z) != 3) { |
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fprintf(stderr, "%s: light source syntax error\n", progname); |
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exit(1); |
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} |
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while ((c = getchar()) != EOF && c != '\n') |
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; |
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printf("\nlight sphere l%d ", ++nlights); |
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printf("0\n0\n4 %g %g %g 1\n", x, y, z); |
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} |
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/************************************************** |
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Background color. A color is simply RGB with values between 0 and 1: |
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"b" R G B |
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Format: |
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b %g %g %g |
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If no background color is set, assume RGB = {0,0,0}. |
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********************/ |
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background() |
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{ |
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float r, g, b; |
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if (scanf("%f %f %f", &r, &g, &b) != 3) { |
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fprintf(stderr, "%s: background syntax error\n", progname); |
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exit(1); |
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} |
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printf("\nvoid glow backg_color\n"); |
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printf("0\n0\n4 %g %g %g 0\n", r, g, b); |
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printf("\nbackg_color source background\n"); |
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printf("0\n0\n4 0 0 1 360\n"); |
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} |
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/**************************************************** |
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Fill color and shading parameters. Description: |
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"f" red green blue Kd Ks Shine T index_of_refraction |
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Format: |
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f %g %g %g %g %g %g %g %g |
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RGB is in terms of 0.0 to 1.0. |
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Kd is the diffuse component, Ks the specular, Shine is the Phong cosine |
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power for highlights, T is transmittance (fraction of light passed per |
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unit). Usually, 0 <= Kd <= 1 and 0 <= Ks <= 1, though it is not required |
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that Kd + Ks == 1. Note that transmitting objects ( T > 0 ) are considered |
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to have two sides for algorithms that need these (normally objects have |
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one side). |
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The fill color is used to color the objects following it until a new color |
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is assigned. |
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*********************/ |
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fill() |
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{ |
| 343 |
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float r, g, b, d, s, p, t, n; |
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if (scanf("%f %f %f %f %f %f %f %f", &r, &g, &b, |
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&d, &s, &p, &t, &n) != 8) { |
| 347 |
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fprintf(stderr, "%s: fill material syntax error\n", progname); |
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exit(1); |
| 349 |
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} |
| 350 |
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d /= 1.-s-t; |
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r *= d; |
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g *= d; |
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b *= d; |
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if (p > 1.) |
| 355 |
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p = 1./p; |
| 356 |
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if (t > .001) { /* has transmission */ |
| 357 |
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printf("\nvoid trans fill\n"); |
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greg |
1.2 |
printf("0\n0\n7 %g %g %g %g 0 %g 1\n", r, g, b, s, t); |
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greg |
1.1 |
} else { /* no transmission */ |
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printf("\nvoid plastic fill\n"); |
| 361 |
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printf("0\n0\n5 %g %g %g %g %g\n", r, g, b, s, p); |
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} |
| 363 |
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} |
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/***************************************************** |
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Cylinder or cone. A cylinder is defined as having a radius and an axis |
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defined by two points, which also define the top and bottom edge of the |
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cylinder. A cone is defined similarly, the difference being that the apex |
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and base radii are different. The apex radius is defined as being smaller |
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than the base radius. Note that the surface exists without endcaps. The |
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cone or cylinder description: |
| 374 |
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"c" |
| 376 |
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base.x base.y base.z base_radius |
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apex.x apex.y apex.z apex_radius |
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Format: |
| 380 |
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c |
| 381 |
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%g %g %g %g |
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%g %g %g %g |
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A negative value for both radii means that only the inside of the object is |
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visible (objects are normally considered one sided, with the outside |
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visible). Note that the base and apex cannot be coincident for a cylinder |
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or cone. |
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************************/ |
| 390 |
|
|
|
| 391 |
|
|
cone() |
| 392 |
|
|
{ |
| 393 |
|
|
static int ncs = 0; |
| 394 |
|
|
int invert; |
| 395 |
|
|
float x0, y0, z0, x1, y1, z1, r0, r1; |
| 396 |
|
|
|
| 397 |
|
|
if (scanf("%f %f %f %f %f %f %f %f", &x0, &y0, &z0, &r0, |
| 398 |
|
|
&x1, &y1, &z1, &r1) != 8) { |
| 399 |
|
|
fprintf(stderr, "%s: cylinder or cone syntax error\n", |
| 400 |
|
|
progname); |
| 401 |
|
|
exit(1); |
| 402 |
|
|
} |
| 403 |
|
|
if (invert = r0 < 0.) { |
| 404 |
|
|
r0 = -r0; |
| 405 |
|
|
r1 = -r1; |
| 406 |
|
|
} |
| 407 |
|
|
if (r0-r1 < .001 && r1-r0 < .001) { /* cylinder */ |
| 408 |
|
|
printf("\nfill %s c%d ", invert?"tube":"cylinder", ++ncs); |
| 409 |
|
|
printf("0\n0\n7\n"); |
| 410 |
|
|
printf("\t%g\t%g\t%g\n", x0, y0, z0); |
| 411 |
|
|
printf("\t%g\t%g\t%g\n", x1, y1, z1); |
| 412 |
|
|
printf("\t%g\n", r0); |
| 413 |
|
|
} else { /* cone */ |
| 414 |
|
|
printf("\nfill %s c%d ", invert?"cup":"cone", ++ncs); |
| 415 |
|
|
printf("0\n0\n8\n"); |
| 416 |
|
|
printf("\t%g\t%g\t%g\n", x0, y0, z0); |
| 417 |
|
|
printf("\t%g\t%g\t%g\n", x1, y1, z1); |
| 418 |
|
|
printf("\t%g\t%g\n", r0, r1); |
| 419 |
|
|
} |
| 420 |
|
|
} |
| 421 |
|
|
|
| 422 |
|
|
|
| 423 |
|
|
/***************************************** |
| 424 |
|
|
|
| 425 |
|
|
Sphere. A sphere is defined by a radius and center position: |
| 426 |
|
|
"s" center.x center.y center.z radius |
| 427 |
|
|
|
| 428 |
|
|
Format: |
| 429 |
|
|
s %g %g %g %g |
| 430 |
|
|
|
| 431 |
|
|
If the radius is negative, then only the sphere's inside is visible |
| 432 |
|
|
(objects are normally considered one sided, with the outside visible). |
| 433 |
|
|
|
| 434 |
|
|
******************/ |
| 435 |
|
|
|
| 436 |
|
|
sphere() |
| 437 |
|
|
{ |
| 438 |
|
|
static int nspheres = 0; |
| 439 |
|
|
float x, y, z, r; |
| 440 |
|
|
|
| 441 |
|
|
if (scanf("%f %f %f %f", &x, &y, &z, &r) != 4) { |
| 442 |
|
|
fprintf(stderr, "%s: sphere syntax error\n", progname); |
| 443 |
|
|
exit(1); |
| 444 |
|
|
} |
| 445 |
|
|
if (r < 0.) { |
| 446 |
|
|
printf("\nfill bubble s%d ", ++nspheres); |
| 447 |
|
|
printf("0\n0\n4 %g %g %g %g\n", x, y, z, -r); |
| 448 |
|
|
} else { |
| 449 |
|
|
printf("\nfill sphere s%d ", ++nspheres); |
| 450 |
|
|
printf("0\n0\n4 %g %g %g %g\n", x, y, z, r); |
| 451 |
|
|
} |
| 452 |
|
|
} |
| 453 |
|
|
|
| 454 |
|
|
|
| 455 |
|
|
/********************************************* |
| 456 |
|
|
|
| 457 |
|
|
Polygon. A polygon is defined by a set of vertices. With these databases, |
| 458 |
|
|
a polygon is defined to have all points coplanar. A polygon has only |
| 459 |
|
|
one side, with the order of the vertices being counterclockwise as you |
| 460 |
|
|
face the polygon (right-handed coordinate system). The first two edges |
| 461 |
|
|
must form a non-zero convex angle, so that the normal and side visibility |
| 462 |
|
|
can be determined. Description: |
| 463 |
|
|
|
| 464 |
|
|
"p" total_vertices |
| 465 |
|
|
vert1.x vert1.y vert1.z |
| 466 |
|
|
[etc. for total_vertices vertices] |
| 467 |
|
|
|
| 468 |
|
|
Format: |
| 469 |
|
|
p %d |
| 470 |
|
|
[ %g %g %g ] <-- for total_vertices vertices |
| 471 |
|
|
|
| 472 |
|
|
-------- |
| 473 |
|
|
|
| 474 |
|
|
Polygonal patch. A patch is defined by a set of vertices and their normals. |
| 475 |
|
|
With these databases, a patch is defined to have all points coplanar. |
| 476 |
|
|
A patch has only one side, with the order of the vertices being |
| 477 |
|
|
counterclockwise as you face the patch (right-handed coordinate system). |
| 478 |
|
|
The first two edges must form a non-zero convex angle, so that the normal |
| 479 |
|
|
and side visibility can be determined. Description: |
| 480 |
|
|
|
| 481 |
|
|
"pp" total_vertices |
| 482 |
|
|
vert1.x vert1.y vert1.z norm1.x norm1.y norm1.z |
| 483 |
|
|
[etc. for total_vertices vertices] |
| 484 |
|
|
|
| 485 |
|
|
Format: |
| 486 |
|
|
pp %d |
| 487 |
|
|
[ %g %g %g %g %g %g ] <-- for total_vertices vertices |
| 488 |
|
|
|
| 489 |
|
|
*******************/ |
| 490 |
|
|
|
| 491 |
|
|
poly() |
| 492 |
|
|
{ |
| 493 |
|
|
static int npolys = 0; |
| 494 |
|
|
int ispatch; |
| 495 |
|
|
int nverts; |
| 496 |
|
|
float x, y, z; |
| 497 |
|
|
|
| 498 |
|
|
ispatch = getchar(); |
| 499 |
|
|
if (ispatch != 'p') { |
| 500 |
|
|
ungetc(ispatch, stdin); |
| 501 |
|
|
ispatch = 0; |
| 502 |
|
|
} |
| 503 |
|
|
if (scanf("%d", &nverts) != 1) |
| 504 |
|
|
goto fmterr; |
| 505 |
|
|
printf("\nfill polygon p%d ", ++npolys); |
| 506 |
|
|
printf("0\n0\n%d\n", 3*nverts); |
| 507 |
|
|
while (nverts-- > 0) { |
| 508 |
|
|
if (scanf("%f %f %f", &x, &y, &z) != 3) |
| 509 |
|
|
goto fmterr; |
| 510 |
|
|
if (ispatch) |
| 511 |
|
|
scanf("%*f %*f %*f"); |
| 512 |
|
|
printf("\t%g\t%g\t%g\n", x, y, z); |
| 513 |
|
|
} |
| 514 |
|
|
return; |
| 515 |
|
|
fmterr: |
| 516 |
|
|
fprintf(stderr, "%s: polygon or patch syntax error\n", progname); |
| 517 |
|
|
exit(1); |
| 518 |
|
|
} |
