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root/radiance/ray/src/common/bsdf.h
Revision: 2.7
Committed: Sat Feb 19 23:42:09 2011 UTC (13 years, 2 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.6: +4 -5 lines
Log Message:
Fixes to BSDF including blurring of angle boundaries

File Contents

# User Rev Content
1 greg 2.7 /* RCSid $Id: bsdf.h,v 2.6 2011/02/19 01:48:59 greg Exp $ */
2 greg 2.4 /*
3     * bsdf.h
4     *
5     * Declarations for bidirectional scattering distribution functions.
6     * Assumes <stdio.h> already included.
7     *
8     * A material is oriented in right-hand coordinate system with X-axis
9     * in the surface plane pointed to the right as seen from the front.
10     * This means the Y-axis is "up" and the Z-axis is the surface normal.
11     *
12     * BSDF vectors always oriented away from surface, even when "incident."
13     *
14     * Created by Greg Ward on 1/10/11.
15     *
16     */
17    
18     #ifndef _BSDF_H_
19     #define _BSDF_H_
20    
21     #include "fvect.h"
22     #include "ccolor.h"
23    
24     #ifdef __cplusplus
25     extern "C" {
26     #endif
27    
28     #define SDnameLn 128 /* maximum BSDF name length */
29     #define SDmaxCh 3 /* maximum # spectral channels */
30    
31     /* Component flags for SDsampBSDF() and SDhemiScatter() */
32     #define SDsampR 0x1 /* include reflection */
33     #define SDsampT 0x2 /* include transmission */
34     #define SDsampS 0x3 /* include scattering (R+T) */
35     #define SDsampSp 0x4 /* include non-diffuse portion */
36     #define SDsampDf 0x8 /* include diffuse portion */
37     #define SDsampSpR 0x5 /* include non-diffuse reflection */
38     #define SDsampSpT 0x6 /* include non-diffuse transmission */
39     #define SDsampSpS 0x7 /* include non-diffuse scattering */
40     #define SDsampAll 0xF /* include everything */
41    
42     /* Projected solid angle query flags fos SDsizeBSDF() */
43 greg 2.7 #define SDqueryVal 0x0 /* query single value */
44     #define SDqueryMin 0x1 /* query minimum proj. solid angle */
45     #define SDqueryMax 0x2 /* query maximum proj. solid angle */
46 greg 2.4
47     /* Error codes: normal return, out of memory, file i/o, file format, bad argument,
48     bad data, unsupported feature, internal error, unknown error */
49     typedef enum {SDEnone=0, SDEmemory, SDEfile, SDEformat, SDEargument,
50     SDEdata, SDEsupport, SDEinternal, SDEunknown} SDError;
51    
52     /* English ASCII strings corresponding to ennumerated errors */
53     extern const char *SDerrorEnglish[];
54    
55     /* Additional information on last error (ASCII English) */
56     extern char SDerrorDetail[];
57    
58     /* Holder for BSDF value and spectral color */
59     typedef struct {
60     double cieY; /* photopic BSDF (Y) value */
61     C_COLOR spec; /* spectral and (x,y) color */
62     } SDValue;
63    
64     /* Cached, encoded, cumulative distribution for one incident (solid) angle */
65     #define SD_CDIST_BASE double cTotal; \
66     struct SDCDst_s *next
67     typedef struct SDCDst_s {
68     SD_CDIST_BASE; /* base fields first */
69     /* ...encoded distribution extends struct */
70     } SDCDst;
71    
72     /* Forward declaration of BSDF component */
73     typedef struct SDComp_s SDComponent;
74    
75     /* Methods needed to handle BSDF components (nothing is optional) */
76     typedef const struct {
77     /* return non-diffuse BSDF */
78     int (*getBSDFs)(float coef[SDmaxCh], const FVECT outVec,
79     const FVECT inVec, const void *dist);
80     /* query non-diffuse PSA for vector */
81     SDError (*queryProjSA)(double *psa, const FVECT vec,
82     int qflags, const void *dist);
83     /* get cumulative distribution */
84     const SDCDst *(*getCDist)(const FVECT inVec, SDComponent *sdc);
85     /* sample cumulative distribution */
86     SDError (*sampCDist)(FVECT outVec, double randX,
87     const SDCDst *cdp);
88     /* free a spectral BSDF component */
89     void (*freeSC)(void *dist);
90     } SDFunc;
91    
92     /* Structure to hold a spectral BSDF component (typedef SDComponent above) */
93     struct SDComp_s {
94     C_COLOR cspec[SDmaxCh]; /* component spectral bases */
95     SDFunc *func; /* methods for this component */
96     void *dist; /* loaded distribution data */
97     SDCDst *cdList; /* cumulative distribution cache */
98     };
99    
100     /* Container for non-diffuse BSDF components */
101     typedef struct {
102     double minProjSA; /* minimum projected solid angle */
103     double maxHemi; /* maximum directional hemispherical */
104     int ncomp; /* number of separate components */
105     SDComponent comp[1]; /* BSDF components (extends struct) */
106     } SDSpectralDF;
107    
108     /* Loaded BSDF data */
109     typedef struct {
110     char name[SDnameLn]; /* BSDF name (derived from file) */
111     char *mgf; /* geometric description (if any) */
112     float dim[3]; /* width, height, thickness (meters) */
113     SDValue rLambFront; /* diffuse front reflectance */
114     SDValue rLambBack; /* diffuse rear reflectance */
115     SDValue tLamb; /* diffuse transmission */
116     SDSpectralDF *rf, *rb, *tf; /* non-diffuse BSDF components */
117     } SDData;
118    
119     /* List of loaded BSDFs */
120     extern struct SDCache_s {
121     SDData bsdf; /* BSDF data */
122     unsigned refcnt; /* how many callers are using us? */
123     struct SDCache_s /* next in cache list */
124     *next;
125     } *SDcacheList; /* Global BSDF cache */
126    
127     /* BSDF cache retention preference */
128     #define SDretainNone 0 /* free unreferenced data (default) */
129     #define SDretainBSDFs 1 /* keep loaded BSDFs in cache */
130     #define SDretainAll 2 /* also keep cumulative cache data */
131    
132     extern int SDretainSet; /* set to SDretainNone by default */
133    
134     /*****************************************************************
135     * The following routines are less commonly used by applications.
136     */
137    
138 greg 2.6 #define SDisLoaded(sd) ((sd)->rLambFront.spec.flags != 0)
139 greg 2.4
140     /* Report an error to the indicated stream (in English) */
141     extern SDError SDreportEnglish(SDError ec, FILE *fp);
142    
143     /* Shorten file path to useable BSDF name, removing suffix */
144     extern void SDclipName(char res[SDnameLn], const char *fname);
145    
146     /* Allocate new spectral distribution function */
147     extern SDSpectralDF *SDnewSpectralDF(int nc);
148    
149     /* Free a spectral distribution function */
150     extern void SDfreeSpectralDF(SDSpectralDF *df);
151    
152     /* Initialize an unused BSDF struct (clears to zeroes) */
153     extern void SDclearBSDF(SDData *sd);
154    
155     /* Load a BSDF struct from the given file (keeps name unchanged) */
156     extern SDError SDloadFile(SDData *sd, const char *fname);
157    
158     /* Free data associated with BSDF struct */
159     extern void SDfreeBSDF(SDData *sd);
160    
161     /* Find writeable BSDF by name, or allocate new cache entry if absent */
162     extern SDData *SDgetCache(const char *bname);
163    
164     /* Free cached cumulative distributions for BSDF component */
165     extern void SDfreeCumulativeCache(SDSpectralDF *df);
166    
167     /* Sample an individual BSDF component */
168     extern SDError SDsampComponent(SDValue *sv, FVECT outVec,
169     const FVECT inVec, double randX,
170     SDComponent *sdc);
171    
172     /* Convert 1-dimensional random variable to N-dimensional */
173     extern void SDmultiSamp(double t[], int n, double randX);
174    
175     /* Map a [0,1]^2 square to a unit radius disk */
176     void SDsquare2disk(double ds[2], double seedx, double seedy);
177    
178     /* Map point on unit disk to a unit square in [0,1]^2 range */
179     void SDdisk2square(double sq[2], double diskx, double disky);
180    
181     /*****************************************************************
182     * The calls below are the ones most applications require.
183     * All directions are assumed to be unit vectors.
184     */
185    
186     /* Get BSDF from cache (or load and cache it on first call) */
187     /* Report any problems to stderr and return NULL on failure */
188     extern const SDData *SDcacheFile(const char *fname);
189    
190     /* Free a BSDF from our cache (clear all if NULL) */
191     extern void SDfreeCache(const SDData *sd);
192    
193     /* Query projected solid angle resolution for non-diffuse BSDF direction */
194     extern SDError SDsizeBSDF(double *projSA, const FVECT vec,
195     int qflags, const SDData *sd);
196    
197     /* Return BSDF for the given incident and scattered ray vectors */
198     extern SDError SDevalBSDF(SDValue *sv, const FVECT outVec,
199     const FVECT inVec, const SDData *sd);
200    
201     /* Compute directional hemispherical scattering at given incident angle */
202     extern double SDdirectHemi(const FVECT inVec,
203     int sflags, const SDData *sd);
204    
205     /* Sample BSDF direction based on the given random variable */
206     extern SDError SDsampBSDF(SDValue *sv, FVECT outVec,
207     const FVECT inVec, double randX,
208     int sflags, const SDData *sd);
209    
210     /*****************************************************************
211     * Vector math for getting between world and local BSDF coordinates.
212     * Directions may be passed unnormalized to these routines.
213     */
214    
215     /* Compute World->BSDF transform from surface normal and up (Y) vector */
216     extern SDError SDcompXform(RREAL vMtx[3][3], const FVECT sNrm,
217     const FVECT uVec);
218    
219     /* Compute inverse transform */
220     extern SDError SDinvXform(RREAL iMtx[3][3], RREAL vMtx[3][3]);
221    
222     /* Transform and normalize direction (column) vector */
223     extern SDError SDmapDir(FVECT resVec, RREAL vMtx[3][3],
224     const FVECT inpVec);
225    
226 greg 2.5 /* System-specific BSDF loading routine (not part of our library) */
227     extern SDData *loadBSDF(char *name);
228    
229     /* System-specific BSDF error translator (not part of our library) */
230     extern char *transSDError(SDError ec);
231    
232 greg 2.4 /*################################################################*/
233     /*######### DEPRECATED DEFINITIONS AWAITING PERMANENT REMOVAL #######*/
234 greg 2.1 /*
235     * Header for BSDF i/o and access routines
236     */
237 greg 2.2
238 greg 2.4 #include "mat4.h"
239 greg 2.1 /* up directions */
240     typedef enum {
241     UDzneg=-3,
242     UDyneg=-2,
243     UDxneg=-1,
244     UDunknown=0,
245     UDxpos=1,
246     UDypos=2,
247     UDzpos=3
248     } UpDir;
249     /* BSDF coordinate calculation routines */
250     /* vectors always point away from surface */
251 greg 2.4
252     typedef int b_vecf2(FVECT v, int n, void *cd);
253     typedef int b_ndxf2(FVECT v, void *cd);
254     typedef double b_radf2(int n, void *cd);
255 greg 2.1
256     /* Bidirectional Scattering Distribution Function */
257     struct BSDF_data {
258     int ninc; /* number of incoming directions */
259     int nout; /* number of outgoing directions */
260 greg 2.3 float dim[3]; /* width, height, thickness (meters) */
261     char *mgf; /* geometric description (if any) */
262 greg 2.1 void *ib_priv; /* input basis private data */
263 greg 2.4 b_vecf2 *ib_vec; /* get input vector from index */
264     b_ndxf2 *ib_ndx; /* get input index from vector */
265     b_radf2 *ib_ohm; /* get input radius for index */
266 greg 2.1 void *ob_priv; /* output basis private data */
267 greg 2.4 b_vecf2 *ob_vec; /* get output vector from index */
268     b_ndxf2 *ob_ndx; /* get output index from vector */
269     b_radf2 *ob_ohm; /* get output radius for index */
270 greg 2.1 float *bsdf; /* scattering distribution data */
271     }; /* bidirectional scattering distrib. func. */
272    
273     #define getBSDF_incvec(v,b,i) (*(b)->ib_vec)(v,i,(b)->ib_priv)
274     #define getBSDF_incndx(b,v) (*(b)->ib_ndx)(v,(b)->ib_priv)
275     #define getBSDF_incohm(b,i) (*(b)->ib_ohm)(i,(b)->ib_priv)
276     #define getBSDF_outvec(v,b,o) (*(b)->ob_vec)(v,o,(b)->ob_priv)
277     #define getBSDF_outndx(b,v) (*(b)->ob_ndx)(v,(b)->ob_priv)
278     #define getBSDF_outohm(b,o) (*(b)->ob_ohm)(o,(b)->ob_priv)
279     #define BSDF_value(b,i,o) (b)->bsdf[(o)*(b)->ninc + (i)]
280    
281     extern struct BSDF_data *load_BSDF(char *fname);
282     extern void free_BSDF(struct BSDF_data *b);
283     extern int r_BSDF_incvec(FVECT v, struct BSDF_data *b, int i,
284     double rv, MAT4 xm);
285     extern int r_BSDF_outvec(FVECT v, struct BSDF_data *b, int o,
286     double rv, MAT4 xm);
287 greg 2.3 extern int getBSDF_xfm(MAT4 xm, FVECT nrm, UpDir ud, char *xfbuf);
288 greg 2.2
289 greg 2.4 /*######### END DEPRECATED DEFINITIONS #######*/
290     /*################################################################*/
291    
292     #ifdef __cplusplus
293     }
294     #endif
295     #endif /* ! _BSDF_H_ */