--- ray/src/rt/pmapmat.c	2015/09/01 16:27:52	2.9
+++ ray/src/rt/pmapmat.c	2016/05/17 17:39:47	2.13
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: pmapmat.c,v 2.9 2015/09/01 16:27:52 greg Exp $";
+static const char RCSid[] = "$Id: pmapmat.c,v 2.13 2016/05/17 17:39:47 rschregle Exp $";
 #endif
 /* 
    ==================================================================
@@ -106,23 +106,25 @@ void photonRay (const RAY *rayIn, RAY *rayOut, 
 {
    rayorigin(rayOut, rayOutType, rayIn, NULL);
    
-   /* Transfer flux */
-   copycolor(rayOut -> rcol, rayIn -> rcol);
-   
-   /* Copy caustic flag & direction for transferred rays */
-   if (rayOutType == PMAP_XFER) {
-      /* rayOut -> rtype |= rayIn -> rtype & SPECULAR; */
-      rayOut -> rtype |= rayIn -> rtype;
-      VCOPY(rayOut -> rdir, rayIn -> rdir);
-   }
-   else if (fluxAtten) {
-      /* Attenuate and normalise flux for scattered rays */
-      multcolor(rayOut -> rcol, fluxAtten);
-      colorNorm(rayOut -> rcol);
-   }
+   if (rayIn) {
+      /* Transfer flux */
+      copycolor(rayOut -> rcol, rayIn -> rcol);
+      
+      /* Copy caustic flag & direction for transferred rays */
+      if (rayOutType == PMAP_XFER) {
+         /* rayOut -> rtype |= rayIn -> rtype & SPECULAR; */
+         rayOut -> rtype |= rayIn -> rtype;
+         VCOPY(rayOut -> rdir, rayIn -> rdir);
+      }
+      else if (fluxAtten) {
+         /* Attenuate and normalise flux for scattered rays */
+         multcolor(rayOut -> rcol, fluxAtten);
+         colorNorm(rayOut -> rcol);
+      }
 
-   /* Propagate index of emitting light source */
-   rayOut -> rsrc = rayIn -> rsrc;
+      /* Propagate index of emitting light source */
+      rayOut -> rsrc = rayIn -> rsrc;
+   }
 }
 
 
@@ -132,17 +134,17 @@ static void addPhotons (const RAY *r)
 {
    if (!r -> rlvl)
       /* Add direct photon map at primary hitpoint */
-      addPhoton(directPmap, r);
+      newPhoton(directPmap, r);
    else {
       /* Add global or precomputed photon map at indirect hitpoint */
-      addPhoton(preCompPmap ? preCompPmap : globalPmap, r);
+      newPhoton(preCompPmap ? preCompPmap : globalPmap, r);
 
       /* Store caustic photon if specular flag set */
       if (PMAP_CAUSTICRAY(r))
-         addPhoton(causticPmap, r);
+         newPhoton(causticPmap, r);
          
       /* Store in contribution photon map */
-      addPhoton(contribPmap, r);
+      newPhoton(contribPmap, r);
    }
 }
 
@@ -978,8 +980,11 @@ static int aliasPhotonScatter (OBJREC *mat, RAY *rayIn
    
    /* Straight replacement? */
    if (!mat -> oargs.nsargs) {
-      mat = objptr(mat -> omod);
-      photonScatter [mat -> otype] (mat, rayIn);
+      /* Skip void modifier! */
+      if (mat -> omod != OVOID) {   
+         mat = objptr(mat -> omod);
+         photonScatter [mat -> otype] (mat, rayIn);
+      }
       
       return 0;
    }
@@ -1250,8 +1255,19 @@ static int mx_dataPhotonScatter (OBJREC *mat, RAY *ray
    if (errno) 
       objerror(mat, WARNING, "compute error");
    else {
-      mat = objptr(mod [pmapRandom(rouletteState) < coef ? 0 : 1]);
-      photonScatter [mat -> otype] (mat, rayIn);
+      OBJECT mxMod = mod [pmapRandom(rouletteState) < coef ? 0 : 1];
+      
+      if (mxMod != OVOID) {
+         mat = objptr(mxMod);
+         photonScatter [mat -> otype] (mat, rayIn);
+      }
+      else {
+         /* Transfer ray if no modifier */
+         RAY rayOut;
+         
+         photonRay(rayIn, &rayOut, PMAP_XFER, NULL);
+         tracePhoton(&rayOut);      
+      }            
    }
    
    return 0;
@@ -1303,8 +1319,19 @@ static int mx_pdataPhotonScatter (OBJREC *mat, RAY *ra
    if (errno) 
       objerror(mat, WARNING, "compute error");
    else {
-      mat = objptr(mod [pmapRandom(rouletteState) < coef ? 0 : 1]);
-      photonScatter [mat -> otype] (mat, rayIn);
+      OBJECT mxMod = mod [pmapRandom(rouletteState) < coef ? 0 : 1];
+      
+      if (mxMod != OVOID) {
+         mat = objptr(mxMod);
+         photonScatter [mat -> otype] (mat, rayIn);
+      }
+      else {
+         /* Transfer ray if no modifier */
+         RAY rayOut;
+         
+         photonRay(rayIn, &rayOut, PMAP_XFER, NULL);
+         tracePhoton(&rayOut);      
+      }      
    }   
    
    return 0;
@@ -1343,8 +1370,19 @@ static int mx_funcPhotonScatter (OBJREC *mat, RAY *ray
    if (errno) 
       objerror(mat, WARNING, "compute error");
    else {         
-      mat = objptr(mod [pmapRandom(rouletteState) < coef ? 0 : 1]);
-      photonScatter [mat -> otype] (mat, rayIn);
+      OBJECT mxMod = mod [pmapRandom(rouletteState) < coef ? 0 : 1];
+      
+      if (mxMod != OVOID) {
+         mat = objptr(mxMod);
+         photonScatter [mat -> otype] (mat, rayIn);
+      }
+      else {
+         /* Transfer ray if no modifier */
+         RAY rayOut;
+         
+         photonRay(rayIn, &rayOut, PMAP_XFER, NULL);
+         tracePhoton(&rayOut);      
+      }
    }
    
    return 0;