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#ifndef lint |
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static const char RCSid[] = "$Id: pmapsrc.c,v 2.17 2018/11/08 00:54:07 greg Exp $"; |
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#endif |
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/* |
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====================================================================== |
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Photon map support routines for emission from light sources |
| 7 |
|
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Roland Schregle (roland.schregle@{hslu.ch, gmail.com}) |
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(c) Fraunhofer Institute for Solar Energy Systems, |
| 10 |
supported by the German Research Foundation (DFG) |
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under the FARESYS project. |
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(c) Lucerne University of Applied Sciences and Arts, |
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supported by the Swiss National Science Foundation (SNSF #147053). |
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(c) Tokyo University of Science, |
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supported by the JSPS KAKENHI Grant Number JP19KK0115. |
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====================================================================== |
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|
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$Id: pmapsrc.c,v 2.17 2018/11/08 00:54:07 greg Exp $" |
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*/ |
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|
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|
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|
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#include "pmapsrc.h" |
| 24 |
#include "pmap.h" |
| 25 |
#include "pmaprand.h" |
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#include "otypes.h" |
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#include "otspecial.h" |
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|
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|
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|
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/* List of photon port modifier names */ |
| 32 |
char *photonPortList [MAXSET + 1] = {NULL}; |
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/* Photon port objects (with modifiers in photonPortMods) */ |
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SRCREC *photonPorts = NULL; |
| 35 |
unsigned numPhotonPorts = 0; |
| 36 |
|
| 37 |
void (*photonPartition [NUMOTYPE]) (EmissionMap*); |
| 38 |
void (*photonOrigin [NUMOTYPE]) (EmissionMap*); |
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|
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|
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|
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/* PHOTON PORT SUPPORT ROUTINES ------------------------------------------ */ |
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|
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|
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|
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/* Get/set photon port orientation flags from/in source flags. |
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* HACK: the port orientation flags are embedded in the source flags and |
| 48 |
* shifted so they won't clobber the latter, since these are interpreted |
| 49 |
* by the *PhotonPartition() and *PhotonOrigin() routines! */ |
| 50 |
#define PMAP_SETPORTFLAGS(portdir) ((int)(portdir) << 14) |
| 51 |
#define PMAP_GETPORTFLAGS(sflags) ((sflags) >> 14) |
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|
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/* Set number of source partitions. |
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* HACK: this is doubled if the source acts as a bidirectionally |
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* emitting photon port, resulting in alternating front/backside partitions, |
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* although essentially each partition is just used twice with opposing |
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* normals. */ |
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#define PMAP_SETNUMPARTITIONS(emap) ( \ |
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(emap) -> numPartitions <<= ( \ |
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(emap) -> port && \ |
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PMAP_GETPORTFLAGS((emap) -> port -> sflags) == PMAP_PORTBI \ |
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) \ |
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) |
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|
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/* Get current source partition and numer of partitions |
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* HACK: halve the number partitions if the source acts as a bidrectionally |
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* emitting photon port, since each partition is used twice with opposing |
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* normals. */ |
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#define PMAP_GETNUMPARTITIONS(emap) (\ |
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(emap) -> numPartitions >> ( \ |
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(emap) -> port && \ |
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PMAP_GETPORTFLAGS((emap) -> port -> sflags) == PMAP_PORTBI \ |
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) \ |
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) |
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#define PMAP_GETPARTITION(emap) ( \ |
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(emap) -> partitionCnt >> ( \ |
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(emap) -> port && \ |
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PMAP_GETPORTFLAGS((emap) -> port -> sflags) == PMAP_PORTBI \ |
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) \ |
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) |
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|
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|
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|
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void getPhotonPorts (char **portList) |
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/* Find geometry declared as photon ports from modifiers in portList */ |
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{ |
| 87 |
OBJECT i; |
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OBJREC *obj, *mat; |
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int mLen; |
| 90 |
char **lp; |
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|
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/* Init photon port objects */ |
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photonPorts = NULL; |
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|
| 95 |
if (!portList [0]) |
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return; |
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|
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for (i = numPhotonPorts = 0; i < nobjects; i++) { |
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obj = objptr(i); |
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mat = findmaterial(obj); |
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|
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/* Check if object is a surface and NOT a light source (duh) and |
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* resolve its material (if any) via any aliases, then check for |
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* inclusion in modifier list; note use of strncmp() to ignore port |
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* flags */ |
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if (issurface(obj -> otype) && mat && !islight(mat -> otype)) { |
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mLen = strlen(mat -> oname); |
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for (lp = portList; *lp && strncmp(mat -> oname, *lp, mLen); lp++); |
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|
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if (*lp) { |
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/* Add photon port */ |
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photonPorts = (SRCREC*)realloc( |
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photonPorts, (numPhotonPorts + 1) * sizeof(SRCREC) |
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); |
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if (!photonPorts) |
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error(USER, "can't allocate photon ports"); |
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|
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photonPorts [numPhotonPorts].so = obj; |
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/* Extract port orientation flags and embed in source flags. |
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* Note setsource() combines (i.e. ORs) these with the actual |
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* source flags below. */ |
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photonPorts [numPhotonPorts].sflags = |
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PMAP_SETPORTFLAGS((*lp) [mLen]); |
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|
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if (!sfun [obj -> otype].of || !sfun[obj -> otype].of -> setsrc) |
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objerror(obj, USER, "illegal photon port"); |
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|
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setsource(photonPorts + numPhotonPorts, obj); |
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numPhotonPorts++; |
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} |
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} |
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} |
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if (!numPhotonPorts) |
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error(USER, "no valid photon ports found"); |
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} |
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|
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|
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|
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static void setPhotonPortNormal (EmissionMap* emap) |
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/* Set normal for current photon port partition based on its orientation */ |
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{ |
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/* Extract photon port orientation flags, set surface normal as follows: |
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-- Port oriented forwards --> flip surface normal to point |
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outwards, since normal points inwards per mkillum convention) |
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-- Port oriented backwards --> surface normal is NOT flipped, |
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since it already points inwards. |
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-- Port is bidirectionally/bilaterally oriented --> flip normal based |
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on the parity of the current partition emap -> partitionCnt. |
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In this case, photon emission alternates between port front/back |
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faces for consecutive partitions. |
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*/ |
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int i, portFlags = PMAP_GETPORTFLAGS(emap -> port -> sflags); |
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|
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if ( |
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portFlags == PMAP_PORTFWD || |
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portFlags == PMAP_PORTBI && !(emap -> partitionCnt & 1) |
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) |
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for (i = 0; i < 3; i++) |
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emap -> ws [i] = -emap -> ws [i]; |
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} |
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|
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|
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|
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/* SOURCE / PHOTON PORT PARTITIONING ROUTINES----------------------------- */ |
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|
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|
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|
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static int flatPhotonPartition2 ( |
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EmissionMap* emap, unsigned long mp, FVECT cent, FVECT u, FVECT v, |
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double du2, double dv2 |
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) |
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/* Recursive part of flatPhotonPartition(..) */ |
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{ |
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FVECT newct, newax; |
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unsigned long npl, npu; |
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|
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if (mp > emap -> maxPartitions) { |
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/* Enlarge partition array */ |
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emap -> maxPartitions <<= 1; |
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emap -> partitions = (unsigned char*)realloc( |
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emap -> partitions, emap -> maxPartitions >> 1 |
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); |
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|
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if (!emap -> partitions) |
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error(USER, "can't allocate source partitions"); |
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|
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memset( |
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emap -> partitions + (emap -> maxPartitions >> 2), 0, |
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emap -> maxPartitions >> 2 |
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); |
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} |
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|
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if (du2 * dv2 <= 1) { /* hit limit? */ |
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setpart(emap -> partitions, emap -> partitionCnt, S0); |
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emap -> partitionCnt++; |
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return 1; |
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} |
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|
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if (du2 > dv2) { /* subdivide in U */ |
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setpart(emap -> partitions, emap -> partitionCnt, SU); |
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emap -> partitionCnt++; |
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newax [0] = 0.5 * u [0]; |
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newax [1] = 0.5 * u [1]; |
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newax [2] = 0.5 * u [2]; |
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u = newax; |
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du2 *= 0.25; |
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} |
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|
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else { /* subdivide in V */ |
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setpart(emap -> partitions, emap -> partitionCnt, SV); |
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emap -> partitionCnt++; |
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newax [0] = 0.5 * v [0]; |
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newax [1] = 0.5 * v [1]; |
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newax [2] = 0.5 * v [2]; |
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v = newax; |
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dv2 *= 0.25; |
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} |
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|
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/* lower half */ |
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newct [0] = cent [0] - newax [0]; |
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newct [1] = cent [1] - newax [1]; |
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newct [2] = cent [2] - newax [2]; |
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npl = flatPhotonPartition2(emap, mp << 1, newct, u, v, du2, dv2); |
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|
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/* upper half */ |
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newct [0] = cent [0] + newax [0]; |
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newct [1] = cent [1] + newax [1]; |
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newct [2] = cent [2] + newax [2]; |
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npu = flatPhotonPartition2(emap, mp << 1, newct, u, v, du2, dv2); |
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|
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/* return total */ |
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return npl + npu; |
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} |
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|
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|
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|
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static void flatPhotonPartition (EmissionMap* emap) |
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/* Partition flat source for photon emission */ |
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{ |
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RREAL *vp; |
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double du2, dv2; |
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|
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memset(emap -> partitions, 0, emap -> maxPartitions >> 1); |
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emap -> partArea = srcsizerat * thescene.cusize; |
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emap -> partArea *= emap -> partArea; |
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vp = emap -> src -> ss [SU]; |
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du2 = DOT(vp, vp) / emap -> partArea; |
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vp = emap -> src -> ss [SV]; |
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dv2 = DOT(vp, vp) / emap -> partArea; |
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emap -> partitionCnt = 0; |
| 251 |
emap -> numPartitions = flatPhotonPartition2( |
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emap, 1, emap -> src -> sloc, |
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emap -> src -> ss [SU], emap -> src -> ss [SV], du2, dv2 |
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); |
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emap -> partitionCnt = 0; |
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emap -> partArea = emap -> src -> ss2 / emap -> numPartitions; |
| 257 |
} |
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|
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|
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|
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static void sourcePhotonPartition (EmissionMap* emap) |
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/* Partition scene cube faces or photon port for photon emission from |
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distant source */ |
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{ |
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if (emap -> port) { |
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/* Relay partitioning to photon port */ |
| 267 |
SRCREC *src = emap -> src; |
| 268 |
emap -> src = emap -> port; |
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photonPartition [emap -> src -> so -> otype] (emap); |
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PMAP_SETNUMPARTITIONS(emap); |
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emap -> src = src; |
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} |
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|
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else { |
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/* No photon ports defined; partition scene cube faces (SUBOPTIMAL) */ |
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memset(emap -> partitions, 0, emap -> maxPartitions >> 1); |
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setpart(emap -> partitions, 0, S0); |
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emap -> partitionCnt = 0; |
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emap -> numPartitions = 1 / srcsizerat; |
| 280 |
emap -> numPartitions *= emap -> numPartitions; |
| 281 |
emap -> partArea = sqr(thescene.cusize) / emap -> numPartitions; |
| 282 |
emap -> numPartitions *= 6; |
| 283 |
} |
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} |
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|
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|
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|
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static void spherePhotonPartition (EmissionMap* emap) |
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/* Partition spherical source into equal solid angles using uniform |
| 290 |
mapping for photon emission */ |
| 291 |
{ |
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unsigned numTheta, numPhi; |
| 293 |
|
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memset(emap -> partitions, 0, emap -> maxPartitions >> 1); |
| 295 |
setpart(emap -> partitions, 0, S0); |
| 296 |
emap -> partArea = 4 * PI * sqr(emap -> src -> srad); |
| 297 |
emap -> numPartitions = |
| 298 |
emap -> partArea / sqr(srcsizerat * thescene.cusize); |
| 299 |
|
| 300 |
numTheta = max(sqrt(2 * emap -> numPartitions / PI) + 0.5, 1); |
| 301 |
numPhi = 0.5 * PI * numTheta + 0.5; |
| 302 |
|
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emap -> numPartitions = (unsigned long)numTheta * numPhi; |
| 304 |
emap -> partitionCnt = 0; |
| 305 |
emap -> partArea /= emap -> numPartitions; |
| 306 |
} |
| 307 |
|
| 308 |
|
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|
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static int cylPhotonPartition2 ( |
| 311 |
EmissionMap* emap, unsigned long mp, FVECT cent, FVECT axis, double d2 |
| 312 |
) |
| 313 |
/* Recursive part of cyPhotonPartition(..) */ |
| 314 |
{ |
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FVECT newct, newax; |
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unsigned long npl, npu; |
| 317 |
|
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if (mp > emap -> maxPartitions) { |
| 319 |
/* Enlarge partition array */ |
| 320 |
emap -> maxPartitions <<= 1; |
| 321 |
emap -> partitions = (unsigned char*)realloc( |
| 322 |
emap -> partitions, emap -> maxPartitions >> 1 |
| 323 |
); |
| 324 |
if (!emap -> partitions) |
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error(USER, "can't allocate source partitions"); |
| 326 |
|
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memset( |
| 328 |
emap -> partitions + (emap -> maxPartitions >> 2), 0, |
| 329 |
emap -> maxPartitions >> 2 |
| 330 |
); |
| 331 |
} |
| 332 |
|
| 333 |
if (d2 <= 1) { |
| 334 |
/* hit limit? */ |
| 335 |
setpart(emap -> partitions, emap -> partitionCnt, S0); |
| 336 |
emap -> partitionCnt++; |
| 337 |
return 1; |
| 338 |
} |
| 339 |
|
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/* subdivide */ |
| 341 |
setpart(emap -> partitions, emap -> partitionCnt, SU); |
| 342 |
emap -> partitionCnt++; |
| 343 |
newax [0] = 0.5 * axis [0]; |
| 344 |
newax [1] = 0.5 * axis [1]; |
| 345 |
newax [2] = 0.5 * axis [2]; |
| 346 |
d2 *= 0.25; |
| 347 |
|
| 348 |
/* lower half */ |
| 349 |
newct [0] = cent [0] - newax [0]; |
| 350 |
newct [1] = cent [1] - newax [1]; |
| 351 |
newct [2] = cent [2] - newax [2]; |
| 352 |
npl = cylPhotonPartition2(emap, mp << 1, newct, newax, d2); |
| 353 |
|
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/* upper half */ |
| 355 |
newct [0] = cent [0] + newax [0]; |
| 356 |
newct [1] = cent [1] + newax [1]; |
| 357 |
newct [2] = cent [2] + newax [2]; |
| 358 |
npu = cylPhotonPartition2(emap, mp << 1, newct, newax, d2); |
| 359 |
|
| 360 |
/* return total */ |
| 361 |
return npl + npu; |
| 362 |
} |
| 363 |
|
| 364 |
|
| 365 |
|
| 366 |
static void cylPhotonPartition (EmissionMap* emap) |
| 367 |
/* Partition cylindrical source for photon emission */ |
| 368 |
{ |
| 369 |
double d2; |
| 370 |
|
| 371 |
memset(emap -> partitions, 0, emap -> maxPartitions >> 1); |
| 372 |
d2 = srcsizerat * thescene.cusize; |
| 373 |
d2 = PI * emap -> src -> ss2 / (2 * emap -> src -> srad * sqr(d2)); |
| 374 |
d2 *= d2 * DOT(emap -> src -> ss [SU], emap -> src -> ss [SU]); |
| 375 |
|
| 376 |
emap -> partitionCnt = 0; |
| 377 |
emap -> numPartitions = cylPhotonPartition2( |
| 378 |
emap, 1, emap -> src -> sloc, emap -> src -> ss [SU], d2 |
| 379 |
); |
| 380 |
emap -> partitionCnt = 0; |
| 381 |
emap -> partArea = PI * emap -> src -> ss2 / emap -> numPartitions; |
| 382 |
} |
| 383 |
|
| 384 |
|
| 385 |
|
| 386 |
/* PHOTON ORIGIN ROUTINES ------------------------------------------------ */ |
| 387 |
|
| 388 |
|
| 389 |
|
| 390 |
static void flatPhotonOrigin (EmissionMap* emap) |
| 391 |
/* Init emission map with photon origin and associated surface axes on |
| 392 |
flat light source surface. Also sets source aperture and sampling |
| 393 |
hemisphere axes at origin */ |
| 394 |
{ |
| 395 |
int i, cent[3], size[3], parr[2]; |
| 396 |
FVECT vpos; |
| 397 |
|
| 398 |
cent [0] = cent [1] = cent [2] = 0; |
| 399 |
size [0] = size [1] = size [2] = emap -> maxPartitions; |
| 400 |
parr [0] = 0; |
| 401 |
parr [1] = PMAP_GETPARTITION(emap); |
| 402 |
|
| 403 |
if (!skipparts(cent, size, parr, emap -> partitions)) |
| 404 |
error(CONSISTENCY, "bad source partition in flatPhotonOrigin"); |
| 405 |
|
| 406 |
vpos [0] = (1 - 2 * pmapRandom(partState)) * size [0] / |
| 407 |
emap -> maxPartitions; |
| 408 |
vpos [1] = (1 - 2 * pmapRandom(partState)) * size [1] / |
| 409 |
emap -> maxPartitions; |
| 410 |
vpos [2] = 0; |
| 411 |
|
| 412 |
for (i = 0; i < 3; i++) |
| 413 |
vpos [i] += (double)cent [i] / emap -> maxPartitions; |
| 414 |
|
| 415 |
/* Get origin */ |
| 416 |
for (i = 0; i < 3; i++) |
| 417 |
emap -> photonOrg [i] = |
| 418 |
emap -> src -> sloc [i] + |
| 419 |
vpos [SU] * emap -> src -> ss [SU][i] + |
| 420 |
vpos [SV] * emap -> src -> ss [SV][i] + |
| 421 |
vpos [SW] * emap -> src -> ss [SW][i]; |
| 422 |
|
| 423 |
/* Get surface axes */ |
| 424 |
VCOPY(emap -> us, emap -> src -> ss [SU]); |
| 425 |
normalize(emap -> us); |
| 426 |
VCOPY(emap -> ws, emap -> src -> ss [SW]); |
| 427 |
/* Flip normal emap -> ws if port and required by its orientation */ |
| 428 |
setPhotonPortNormal(emap); |
| 429 |
fcross(emap -> vs, emap -> ws, emap -> us); |
| 430 |
|
| 431 |
/* Get hemisphere axes & aperture */ |
| 432 |
if (emap -> src -> sflags & SSPOT) { |
| 433 |
VCOPY(emap -> wh, emap -> src -> sl.s -> aim); |
| 434 |
i = 0; |
| 435 |
|
| 436 |
do { |
| 437 |
emap -> vh [0] = emap -> vh [1] = emap -> vh [2] = 0; |
| 438 |
emap -> vh [i++] = 1; |
| 439 |
fcross(emap -> uh, emap -> vh, emap -> wh); |
| 440 |
} while (normalize(emap -> uh) < FTINY); |
| 441 |
|
| 442 |
fcross(emap -> vh, emap -> wh, emap -> uh); |
| 443 |
emap -> cosThetaMax = 1 - emap -> src -> sl.s -> siz / (2 * PI); |
| 444 |
} |
| 445 |
|
| 446 |
else { |
| 447 |
VCOPY(emap -> uh, emap -> us); |
| 448 |
VCOPY(emap -> vh, emap -> vs); |
| 449 |
VCOPY(emap -> wh, emap -> ws); |
| 450 |
emap -> cosThetaMax = 0; |
| 451 |
} |
| 452 |
} |
| 453 |
|
| 454 |
|
| 455 |
|
| 456 |
static void spherePhotonOrigin (EmissionMap* emap) |
| 457 |
/* Init emission map with photon origin and associated surface axes on |
| 458 |
spherical light source. Also sets source aperture and sampling |
| 459 |
hemisphere axes at origin */ |
| 460 |
{ |
| 461 |
int i = 0; |
| 462 |
unsigned numTheta, numPhi, t, p; |
| 463 |
RREAL cosTheta, sinTheta, phi; |
| 464 |
|
| 465 |
/* Get current partition */ |
| 466 |
numTheta = max(sqrt(2 * PMAP_GETNUMPARTITIONS(emap) / PI) + 0.5, 1); |
| 467 |
numPhi = 0.5 * PI * numTheta + 0.5; |
| 468 |
|
| 469 |
t = PMAP_GETPARTITION(emap) / numPhi; |
| 470 |
p = PMAP_GETPARTITION(emap) - t * numPhi; |
| 471 |
|
| 472 |
emap -> ws [2] = cosTheta = 1 - 2 * (t + pmapRandom(partState)) / numTheta; |
| 473 |
sinTheta = sqrt(1 - sqr(cosTheta)); |
| 474 |
phi = 2 * PI * (p + pmapRandom(partState)) / numPhi; |
| 475 |
emap -> ws [0] = cos(phi) * sinTheta; |
| 476 |
emap -> ws [1] = sin(phi) * sinTheta; |
| 477 |
/* Flip normal emap -> ws if port and required by its orientation */ |
| 478 |
setPhotonPortNormal(emap); |
| 479 |
|
| 480 |
/* Get surface axes us & vs perpendicular to ws */ |
| 481 |
do { |
| 482 |
emap -> vs [0] = emap -> vs [1] = emap -> vs [2] = 0; |
| 483 |
emap -> vs [i++] = 1; |
| 484 |
fcross(emap -> us, emap -> vs, emap -> ws); |
| 485 |
} while (normalize(emap -> us) < FTINY); |
| 486 |
|
| 487 |
fcross(emap -> vs, emap -> ws, emap -> us); |
| 488 |
|
| 489 |
/* Get origin */ |
| 490 |
for (i = 0; i < 3; i++) |
| 491 |
emap -> photonOrg [i] = emap -> src -> sloc [i] + |
| 492 |
emap -> src -> srad * emap -> ws [i]; |
| 493 |
|
| 494 |
/* Get hemisphere axes & aperture */ |
| 495 |
if (emap -> src -> sflags & SSPOT) { |
| 496 |
VCOPY(emap -> wh, emap -> src -> sl.s -> aim); |
| 497 |
i = 0; |
| 498 |
|
| 499 |
do { |
| 500 |
emap -> vh [0] = emap -> vh [1] = emap -> vh [2] = 0; |
| 501 |
emap -> vh [i++] = 1; |
| 502 |
fcross(emap -> uh, emap -> vh, emap -> wh); |
| 503 |
} while (normalize(emap -> uh) < FTINY); |
| 504 |
|
| 505 |
fcross(emap -> vh, emap -> wh, emap -> uh); |
| 506 |
emap -> cosThetaMax = 1 - emap -> src -> sl.s -> siz / (2 * PI); |
| 507 |
} |
| 508 |
|
| 509 |
else { |
| 510 |
VCOPY(emap -> uh, emap -> us); |
| 511 |
VCOPY(emap -> vh, emap -> vs); |
| 512 |
VCOPY(emap -> wh, emap -> ws); |
| 513 |
emap -> cosThetaMax = 0; |
| 514 |
} |
| 515 |
} |
| 516 |
|
| 517 |
|
| 518 |
|
| 519 |
static void sourcePhotonOrigin (EmissionMap* emap) |
| 520 |
/* Init emission map with photon origin and associated surface axes |
| 521 |
on scene cube face for distant light source. Also sets source |
| 522 |
aperture (solid angle) and sampling hemisphere axes at origin */ |
| 523 |
{ |
| 524 |
unsigned long i, partsPerDim, partsPerFace; |
| 525 |
unsigned face; |
| 526 |
RREAL du, dv; |
| 527 |
|
| 528 |
if (emap -> port) { |
| 529 |
/* Relay to photon port; get origin on its surface */ |
| 530 |
SRCREC *src = emap -> src; |
| 531 |
emap -> src = emap -> port; |
| 532 |
photonOrigin [emap -> src -> so -> otype] (emap); |
| 533 |
emap -> src = src; |
| 534 |
} |
| 535 |
|
| 536 |
else { |
| 537 |
/* No ports defined, so get origin on scene cube face (SUBOPTIMAL) */ |
| 538 |
/* Get current face from partition number */ |
| 539 |
partsPerDim = 1 / srcsizerat; |
| 540 |
partsPerFace = sqr(partsPerDim); |
| 541 |
face = emap -> partitionCnt / partsPerFace; |
| 542 |
if (!(emap -> partitionCnt % partsPerFace)) { |
| 543 |
/* Skipped to a new face; get its normal */ |
| 544 |
emap -> ws [0] = emap -> ws [1] = emap -> ws [2] = 0; |
| 545 |
emap -> ws [face >> 1] = face & 1 ? 1 : -1; |
| 546 |
|
| 547 |
/* Get surface axes us & vs perpendicular to ws */ |
| 548 |
face >>= 1; |
| 549 |
emap -> vs [0] = emap -> vs [1] = emap -> vs [2] = 0; |
| 550 |
emap -> vs [(face + (emap -> ws [face] > 0 ? 2 : 1)) % 3] = 1; |
| 551 |
fcross(emap -> us, emap -> vs, emap -> ws); |
| 552 |
} |
| 553 |
|
| 554 |
/* Get jittered offsets within face from partition number |
| 555 |
(in range [-0.5, 0.5]) */ |
| 556 |
i = emap -> partitionCnt % partsPerFace; |
| 557 |
du = (i / partsPerDim + pmapRandom(partState)) / partsPerDim - 0.5; |
| 558 |
dv = (i % partsPerDim + pmapRandom(partState)) / partsPerDim - 0.5; |
| 559 |
|
| 560 |
/* Jittered destination point within partition */ |
| 561 |
for (i = 0; i < 3; i++) |
| 562 |
emap -> photonOrg [i] = thescene.cuorg [i] + thescene.cusize * ( |
| 563 |
0.5 + du * emap -> us [i] + dv * emap -> vs [i] + |
| 564 |
0.5 * emap -> ws [i] |
| 565 |
); |
| 566 |
} |
| 567 |
|
| 568 |
/* Get hemisphere axes & aperture */ |
| 569 |
VCOPY(emap -> wh, emap -> src -> sloc); |
| 570 |
i = 0; |
| 571 |
|
| 572 |
do { |
| 573 |
emap -> vh [0] = emap -> vh [1] = emap -> vh [2] = 0; |
| 574 |
emap -> vh [i++] = 1; |
| 575 |
fcross(emap -> uh, emap -> vh, emap -> wh); |
| 576 |
} while (normalize(emap -> uh) < FTINY); |
| 577 |
|
| 578 |
fcross(emap -> vh, emap -> wh, emap -> uh); |
| 579 |
|
| 580 |
/* Get aperture */ |
| 581 |
emap -> cosThetaMax = 1 - emap -> src -> ss2 / (2 * PI); |
| 582 |
emap -> cosThetaMax = min(1, max(-1, emap -> cosThetaMax)); |
| 583 |
} |
| 584 |
|
| 585 |
|
| 586 |
|
| 587 |
static void cylPhotonOrigin (EmissionMap* emap) |
| 588 |
/* Init emission map with photon origin and associated surface axes |
| 589 |
on cylindrical light source surface. Also sets source aperture |
| 590 |
and sampling hemisphere axes at origin */ |
| 591 |
{ |
| 592 |
int i, cent[3], size[3], parr[2]; |
| 593 |
FVECT v; |
| 594 |
|
| 595 |
cent [0] = cent [1] = cent [2] = 0; |
| 596 |
size [0] = size [1] = size [2] = emap -> maxPartitions; |
| 597 |
parr [0] = 0; |
| 598 |
parr [1] = PMAP_GETPARTITION(emap); |
| 599 |
|
| 600 |
if (!skipparts(cent, size, parr, emap -> partitions)) |
| 601 |
error(CONSISTENCY, "bad source partition in cylPhotonOrigin"); |
| 602 |
|
| 603 |
v [SU] = 0; |
| 604 |
v [SV] = (1 - 2 * pmapRandom(partState)) * (double)size [1] / |
| 605 |
emap -> maxPartitions; |
| 606 |
v [SW] = (1 - 2 * pmapRandom(partState)) * (double)size [2] / |
| 607 |
emap -> maxPartitions; |
| 608 |
normalize(v); |
| 609 |
v [SU] = (1 - 2 * pmapRandom(partState)) * (double)size [1] / |
| 610 |
emap -> maxPartitions; |
| 611 |
|
| 612 |
for (i = 0; i < 3; i++) |
| 613 |
v [i] += (double)cent [i] / emap -> maxPartitions; |
| 614 |
|
| 615 |
/* Get surface axes */ |
| 616 |
for (i = 0; i < 3; i++) |
| 617 |
emap -> photonOrg [i] = emap -> ws [i] = ( |
| 618 |
v [SV] * emap -> src -> ss [SV][i] + |
| 619 |
v [SW] * emap -> src -> ss [SW][i] |
| 620 |
) / 0.8559; |
| 621 |
|
| 622 |
/* Flip normal emap -> ws if port and required by its orientation */ |
| 623 |
setPhotonPortNormal(emap); |
| 624 |
|
| 625 |
normalize(emap -> ws); |
| 626 |
VCOPY(emap -> us, emap -> src -> ss [SU]); |
| 627 |
normalize(emap -> us); |
| 628 |
fcross(emap -> vs, emap -> ws, emap -> us); |
| 629 |
|
| 630 |
/* Get origin */ |
| 631 |
for (i = 0; i < 3; i++) |
| 632 |
emap -> photonOrg [i] += |
| 633 |
v [SU] * emap -> src -> ss [SU][i] + emap -> src -> sloc [i]; |
| 634 |
|
| 635 |
/* Get hemisphere axes & aperture */ |
| 636 |
if (emap -> src -> sflags & SSPOT) { |
| 637 |
VCOPY(emap -> wh, emap -> src -> sl.s -> aim); |
| 638 |
i = 0; |
| 639 |
|
| 640 |
do { |
| 641 |
emap -> vh [0] = emap -> vh [1] = emap -> vh [2] = 0; |
| 642 |
emap -> vh [i++] = 1; |
| 643 |
fcross(emap -> uh, emap -> vh, emap -> wh); |
| 644 |
} while (normalize(emap -> uh) < FTINY); |
| 645 |
|
| 646 |
fcross(emap -> vh, emap -> wh, emap -> uh); |
| 647 |
emap -> cosThetaMax = 1 - emap -> src -> sl.s -> siz / (2 * PI); |
| 648 |
} |
| 649 |
|
| 650 |
else { |
| 651 |
VCOPY(emap -> uh, emap -> us); |
| 652 |
VCOPY(emap -> vh, emap -> vs); |
| 653 |
VCOPY(emap -> wh, emap -> ws); |
| 654 |
emap -> cosThetaMax = 0; |
| 655 |
} |
| 656 |
} |
| 657 |
|
| 658 |
|
| 659 |
|
| 660 |
/* PHOTON EMISSION ROUTINES ---------------------------------------------- */ |
| 661 |
|
| 662 |
|
| 663 |
|
| 664 |
static void defaultEmissionFunc (EmissionMap* emap) |
| 665 |
/* Default behaviour when no emission funcs defined for this source type */ |
| 666 |
{ |
| 667 |
objerror(emap -> src -> so, INTERNAL, |
| 668 |
"undefined photon emission function"); |
| 669 |
} |
| 670 |
|
| 671 |
|
| 672 |
|
| 673 |
void initPhotonEmissionFuncs () |
| 674 |
/* Init photonPartition[] and photonOrigin[] dispatch tables */ |
| 675 |
{ |
| 676 |
int i; |
| 677 |
|
| 678 |
for (i = 0; i < NUMOTYPE; i++) |
| 679 |
photonPartition [i] = photonOrigin [i] = defaultEmissionFunc; |
| 680 |
|
| 681 |
photonPartition [OBJ_FACE] = photonPartition [OBJ_RING] = flatPhotonPartition; |
| 682 |
photonPartition [OBJ_SOURCE] = sourcePhotonPartition; |
| 683 |
photonPartition [OBJ_SPHERE] = spherePhotonPartition; |
| 684 |
photonPartition [OBJ_CYLINDER] = cylPhotonPartition; |
| 685 |
photonOrigin [OBJ_FACE] = photonOrigin [OBJ_RING] = flatPhotonOrigin; |
| 686 |
photonOrigin [OBJ_SOURCE] = sourcePhotonOrigin; |
| 687 |
photonOrigin [OBJ_SPHERE] = spherePhotonOrigin; |
| 688 |
photonOrigin [OBJ_CYLINDER] = cylPhotonOrigin; |
| 689 |
} |
| 690 |
|
| 691 |
|
| 692 |
|
| 693 |
void initPhotonEmission (EmissionMap *emap, float numPdfSamples) |
| 694 |
/* Initialise photon emission from partitioned light source emap -> src; |
| 695 |
* this involves integrating the flux emitted from the current photon |
| 696 |
* origin emap -> photonOrg and setting up a PDF to sample the emission |
| 697 |
* distribution with numPdfSamples samples */ |
| 698 |
{ |
| 699 |
unsigned i, t, p; |
| 700 |
double phi, cosTheta, sinTheta, du, dv, dOmega, thetaScale; |
| 701 |
EmissionSample* sample; |
| 702 |
const OBJREC* mod = findmaterial(emap -> src -> so); |
| 703 |
static RAY r; |
| 704 |
|
| 705 |
photonOrigin [emap -> src -> so -> otype] (emap); |
| 706 |
setcolor(emap -> partFlux, 0, 0, 0); |
| 707 |
emap -> cdf = 0; |
| 708 |
emap -> numSamples = 0; |
| 709 |
cosTheta = DOT(emap -> ws, emap -> wh); |
| 710 |
|
| 711 |
if (cosTheta <= 0 && sqrt(1-sqr(cosTheta)) <= emap -> cosThetaMax + FTINY) |
| 712 |
/* Aperture completely below surface; no emission from current origin */ |
| 713 |
return; |
| 714 |
|
| 715 |
if ( |
| 716 |
mod -> omod == OVOID && !emap -> port && ( |
| 717 |
cosTheta >= 1 - FTINY || ( |
| 718 |
emap -> src -> sflags & SDISTANT && |
| 719 |
acos(cosTheta) + acos(emap -> cosThetaMax) <= 0.5 * PI |
| 720 |
) |
| 721 |
) |
| 722 |
) { |
| 723 |
/* Source is unmodified and has no port (which requires testing for |
| 724 |
occlusion), and is either local with normal aligned aperture or |
| 725 |
distant with aperture above surface |
| 726 |
--> get flux & PDF via analytical solution */ |
| 727 |
setcolor( |
| 728 |
emap -> partFlux, mod -> oargs.farg [0], mod -> oargs.farg [1], |
| 729 |
mod -> oargs.farg [2] |
| 730 |
); |
| 731 |
|
| 732 |
/* Multiply radiance by projected Omega * dA to get flux */ |
| 733 |
scalecolor( |
| 734 |
emap -> partFlux, |
| 735 |
PI * cosTheta * (1 - sqr(max(emap -> cosThetaMax, 0))) * |
| 736 |
emap -> partArea |
| 737 |
); |
| 738 |
} |
| 739 |
|
| 740 |
else { |
| 741 |
/* Source is either modified, has a port, is local with off-normal |
| 742 |
aperture, or distant with aperture partly below surface |
| 743 |
--> get flux via numerical integration */ |
| 744 |
thetaScale = (1 - emap -> cosThetaMax); |
| 745 |
|
| 746 |
/* Figga out numba of aperture samples for integration; |
| 747 |
numTheta / numPhi ratio is 1 / PI */ |
| 748 |
du = sqrt(pdfSamples * 2 * thetaScale); |
| 749 |
emap -> numTheta = max(du + 0.5, 1); |
| 750 |
emap -> numPhi = max(PI * du + 0.5, 1); |
| 751 |
|
| 752 |
dOmega = 2 * PI * thetaScale / (emap -> numTheta * emap -> numPhi); |
| 753 |
thetaScale /= emap -> numTheta; |
| 754 |
|
| 755 |
/* Allocate PDF, baby */ |
| 756 |
sample = emap -> samples = (EmissionSample*)realloc( |
| 757 |
emap -> samples, |
| 758 |
sizeof(EmissionSample) * emap -> numTheta * emap -> numPhi |
| 759 |
); |
| 760 |
if (!emap -> samples) |
| 761 |
error(USER, "can't allocate emission PDF"); |
| 762 |
|
| 763 |
VCOPY(r.rorg, emap -> photonOrg); |
| 764 |
VCOPY(r.rop, emap -> photonOrg); |
| 765 |
r.rmax = 0; |
| 766 |
|
| 767 |
for (t = 0; t < emap -> numTheta; t++) { |
| 768 |
for (p = 0; p < emap -> numPhi; p++) { |
| 769 |
/* This uniform mapping handles 0 <= thetaMax <= PI */ |
| 770 |
cosTheta = 1 - (t + pmapRandom(emitState)) * thetaScale; |
| 771 |
sinTheta = sqrt(1 - sqr(cosTheta)); |
| 772 |
phi = 2 * PI * (p + pmapRandom(emitState)) / emap -> numPhi; |
| 773 |
du = cos(phi) * sinTheta; |
| 774 |
dv = sin(phi) * sinTheta; |
| 775 |
rayorigin(&r, PRIMARY, NULL, NULL); |
| 776 |
|
| 777 |
for (i = 0; i < 3; i++) |
| 778 |
r.rdir [i] = ( |
| 779 |
du * emap -> uh [i] + dv * emap -> vh [i] + |
| 780 |
cosTheta * emap -> wh [i] |
| 781 |
); |
| 782 |
|
| 783 |
/* Sample behind surface? */ |
| 784 |
VCOPY(r.ron, emap -> ws); |
| 785 |
if ((r.rod = DOT(r.rdir, r.ron)) <= 0) |
| 786 |
continue; |
| 787 |
|
| 788 |
/* Get radiance emitted in this direction; to get flux we |
| 789 |
multiply by cos(theta_surface), dOmega, and dA. Ray |
| 790 |
is directed towards light source for raytexture(). */ |
| 791 |
if (!(emap -> src -> sflags & SDISTANT)) |
| 792 |
for (i = 0; i < 3; i++) |
| 793 |
r.rdir [i] = -r.rdir [i]; |
| 794 |
|
| 795 |
/* Port occluded in this direction? */ |
| 796 |
if (emap -> port && localhit(&r, &thescene)) |
| 797 |
continue; |
| 798 |
|
| 799 |
raytexture(&r, mod -> omod); |
| 800 |
setcolor( |
| 801 |
r.rcol, mod -> oargs.farg [0], mod -> oargs.farg [1], |
| 802 |
mod -> oargs.farg [2] |
| 803 |
); |
| 804 |
multcolor(r.rcol, r.pcol); |
| 805 |
|
| 806 |
/* Multiply by cos(theta_surface) */ |
| 807 |
scalecolor(r.rcol, r.rod); |
| 808 |
|
| 809 |
/* Add PDF sample if nonzero; importance info for photon emission |
| 810 |
* could go here... */ |
| 811 |
if (colorAvg(r.rcol)) { |
| 812 |
copycolor(sample -> pdf, r.rcol); |
| 813 |
sample -> cdf = emap -> cdf += colorAvg(sample -> pdf); |
| 814 |
sample -> theta = t; |
| 815 |
sample++ -> phi = p; |
| 816 |
emap -> numSamples++; |
| 817 |
addcolor(emap -> partFlux, r.rcol); |
| 818 |
} |
| 819 |
} |
| 820 |
} |
| 821 |
|
| 822 |
/* Multiply by dOmega * dA */ |
| 823 |
scalecolor(emap -> partFlux, dOmega * emap -> partArea); |
| 824 |
} |
| 825 |
} |
| 826 |
|
| 827 |
|
| 828 |
|
| 829 |
#define vomitPhoton emitPhoton |
| 830 |
#define bluarrrghPhoton vomitPhoton |
| 831 |
|
| 832 |
void emitPhoton (const EmissionMap* emap, RAY* ray) |
| 833 |
/* Emit photon from current partition emap -> partitionCnt based on |
| 834 |
emission distribution. Returns new photon ray. */ |
| 835 |
{ |
| 836 |
unsigned long i, lo, hi; |
| 837 |
const EmissionSample* sample = emap -> samples; |
| 838 |
RREAL du, dv, cosTheta, cosThetaSqr, sinTheta, phi; |
| 839 |
const OBJREC* mod = findmaterial(emap -> src -> so); |
| 840 |
|
| 841 |
/* Choose a new origin within current partition for every |
| 842 |
emitted photon to break up clustering artifacts */ |
| 843 |
photonOrigin [emap -> src -> so -> otype] ((EmissionMap*)emap); |
| 844 |
/* If we have a local glow source with a maximum radius, then |
| 845 |
restrict our photon to the specified distance, otherwise we set |
| 846 |
the limit imposed by photonMaxDist (or no limit if 0) */ |
| 847 |
if ( |
| 848 |
mod -> otype == MAT_GLOW && |
| 849 |
!(emap -> src -> sflags & SDISTANT) && mod -> oargs.farg[3] > FTINY |
| 850 |
) |
| 851 |
ray -> rmax = mod -> oargs.farg[3]; |
| 852 |
else |
| 853 |
ray -> rmax = photonMaxDist; |
| 854 |
rayorigin(ray, PRIMARY, NULL, NULL); |
| 855 |
|
| 856 |
if (!emap -> numSamples) { |
| 857 |
/* Source is unmodified and has no port, and either local with |
| 858 |
normal aligned aperture, or distant with aperture above surface |
| 859 |
--> use cosine weighted distribution */ |
| 860 |
cosThetaSqr = (1 - |
| 861 |
pmapRandom(emitState) * (1 - sqr(max(emap -> cosThetaMax, 0))) |
| 862 |
); |
| 863 |
cosTheta = sqrt(cosThetaSqr); |
| 864 |
sinTheta = sqrt(1 - cosThetaSqr); |
| 865 |
phi = 2 * PI * pmapRandom(emitState); |
| 866 |
setcolor( |
| 867 |
ray -> rcol, mod -> oargs.farg [0], mod -> oargs.farg [1], |
| 868 |
mod -> oargs.farg [2] |
| 869 |
); |
| 870 |
} |
| 871 |
|
| 872 |
else { |
| 873 |
/* Source is either modified, has a port, is local with off-normal |
| 874 |
aperture, or distant with aperture partly below surface |
| 875 |
--> choose direction from constructed cumulative distribution |
| 876 |
function with Monte Carlo inversion using binary search. */ |
| 877 |
du = pmapRandom(emitState) * emap -> cdf; |
| 878 |
lo = 1; |
| 879 |
hi = emap -> numSamples; |
| 880 |
|
| 881 |
while (hi > lo) { |
| 882 |
i = (lo + hi) >> 1; |
| 883 |
sample = emap -> samples + i - 1; |
| 884 |
|
| 885 |
if (sample -> cdf >= du) |
| 886 |
hi = i; |
| 887 |
if (sample -> cdf < du) |
| 888 |
lo = i + 1; |
| 889 |
} |
| 890 |
|
| 891 |
/* This is a uniform mapping, mon */ |
| 892 |
cosTheta = (1 - |
| 893 |
(sample -> theta + pmapRandom(emitState)) * |
| 894 |
(1 - emap -> cosThetaMax) / emap -> numTheta |
| 895 |
); |
| 896 |
sinTheta = sqrt(1 - sqr(cosTheta)); |
| 897 |
phi = 2 * PI * (sample -> phi + pmapRandom(emitState)) / emap -> numPhi; |
| 898 |
copycolor(ray -> rcol, sample -> pdf); |
| 899 |
} |
| 900 |
|
| 901 |
/* Normalize photon flux so that average over RGB is 1 */ |
| 902 |
colorNorm(ray -> rcol); |
| 903 |
|
| 904 |
VCOPY(ray -> rorg, emap -> photonOrg); |
| 905 |
du = cos(phi) * sinTheta; |
| 906 |
dv = sin(phi) * sinTheta; |
| 907 |
|
| 908 |
for (i = 0; i < 3; i++) |
| 909 |
ray -> rdir [i] = du * emap -> uh [i] + dv * emap -> vh [i] + |
| 910 |
cosTheta * emap -> wh [i]; |
| 911 |
|
| 912 |
if (emap -> src -> sflags & SDISTANT) |
| 913 |
/* Distant source; reverse ray direction to point into the scene. */ |
| 914 |
for (i = 0; i < 3; i++) |
| 915 |
ray -> rdir [i] = -ray -> rdir [i]; |
| 916 |
|
| 917 |
if (emap -> port) |
| 918 |
/* Photon emitted from port; move origin just behind port so it |
| 919 |
will be scattered */ |
| 920 |
for (i = 0; i < 3; i++) |
| 921 |
ray -> rorg [i] -= 2 * FTINY * ray -> rdir [i]; |
| 922 |
|
| 923 |
/* Assign emitting light source index */ |
| 924 |
ray -> rsrc = emap -> src - source; |
| 925 |
} |
| 926 |
|
| 927 |
|
| 928 |
|
| 929 |
/* SOURCE CONTRIBS FROM DIRECT / VOLUME PHOTONS -------------------------- */ |
| 930 |
|
| 931 |
|
| 932 |
|
| 933 |
void multDirectPmap (RAY *r) |
| 934 |
/* Factor irradiance from direct photons into r -> rcol; interface to |
| 935 |
* direct() */ |
| 936 |
{ |
| 937 |
COLOR photonIrrad; |
| 938 |
|
| 939 |
/* Lookup direct photon irradiance */ |
| 940 |
(directPmap -> lookup)(directPmap, r, photonIrrad); |
| 941 |
|
| 942 |
/* Multiply with coefficient in ray */ |
| 943 |
multcolor(r -> rcol, photonIrrad); |
| 944 |
|
| 945 |
return; |
| 946 |
} |
| 947 |
|
| 948 |
|
| 949 |
|
| 950 |
void inscatterVolumePmap (RAY *r, COLOR inscatter) |
| 951 |
/* Add inscattering from volume photon map; interface to srcscatter() */ |
| 952 |
{ |
| 953 |
/* Add ambient in-scattering via lookup callback */ |
| 954 |
(volumePmap -> lookup)(volumePmap, r, inscatter); |
| 955 |
} |
| 956 |
|
