1 files changed, 23 insertions, 8 deletions

diff --git a/intern/cycles/kernel/bvh/volume_all.h b/intern/cycles/kernel/bvh/volume_all.h
index d06ea8fe557..c6eeb07a14d 100644
--- a/intern/cycles/kernel/bvh/volume_all.h
+++ b/intern/cycles/kernel/bvh/volume_all.h
@@ -44,12 +44,12 @@ ccl_device_inline
   int node_addr = kernel_data.bvh.root;
 
   /* ray parameters in registers */
-  const float tmax = ray->t;
   float3 P = ray->P;
   float3 dir = bvh_clamp_direction(ray->D);
   float3 idir = bvh_inverse_direction(dir);
+  float tmin = ray->tmin;
   int object = OBJECT_NONE;
-  float isect_t = tmax;
+  float isect_t = ray->tmax;
 
 #if BVH_FEATURE(BVH_MOTION)
   Transform ob_itfm;
@@ -58,7 +58,7 @@ ccl_device_inline
   int num_hits_in_instance = 0;
 
   uint num_hits = 0;
-  isect_array->t = tmax;
+  isect_array->t = ray->tmax;
 
   /* traversal loop */
   do {
@@ -75,6 +75,7 @@ ccl_device_inline
                                        dir,
 #endif
                                        idir,
+                                       tmin,
                                        isect_t,
                                        node_addr,
                                        visibility,
@@ -141,8 +142,16 @@ ccl_device_inline
                 if ((object_flag & SD_OBJECT_HAS_VOLUME) == 0) {
                   continue;
                 }
-                hit = triangle_intersect(
-                    kg, isect_array, P, dir, isect_t, visibility, prim_object, prim, prim_addr);
+                hit = triangle_intersect(kg,
+                                         isect_array,
+                                         P,
+                                         dir,
+                                         tmin,
+                                         isect_t,
+                                         visibility,
+                                         prim_object,
+                                         prim,
+                                         prim_addr);
                 if (hit) {
                   /* Move on to next entry in intersections array. */
                   isect_array++;
@@ -189,6 +198,7 @@ ccl_device_inline
                                                 isect_array,
                                                 P,
                                                 dir,
+                                                tmin,
                                                 isect_t,
                                                 ray->time,
                                                 visibility,
@@ -232,11 +242,15 @@ ccl_device_inline
           int object_flag = kernel_data_fetch(object_flag, object);
           if (object_flag & SD_OBJECT_HAS_VOLUME) {
 #if BVH_FEATURE(BVH_MOTION)
-            isect_t *= bvh_instance_motion_push(kg, object, ray, &P, &dir, &idir, &ob_itfm);
+            const float t_world_to_instance = bvh_instance_motion_push(
+                kg, object, ray, &P, &dir, &idir, &ob_itfm);
 #else
-            isect_t *= bvh_instance_push(kg, object, ray, &P, &dir, &idir);
+            const float t_world_to_instance = bvh_instance_push(kg, object, ray, &P, &dir, &idir);
 #endif
 
+            isect_t *= t_world_to_instance;
+            tmin *= t_world_to_instance;
+
             num_hits_in_instance = 0;
             isect_array->t = isect_t;
 
@@ -280,7 +294,8 @@ ccl_device_inline
 #endif
       }
 
-      isect_t = tmax;
+      tmin = ray->tmin;
+      isect_t = ray->tmax;
       isect_array->t = isect_t;
 
       object = OBJECT_NONE;