intern/cycles/kernel/device/cpu/bvh.h

@@ -79,6 +79,7 @@ struct CCLShadowContext
 #endif
   IntegratorShadowState isect_s;
   float throughput;
+  float max_t;
   bool opaque_hit;
   numhit_t max_hits;
   numhit_t num_hits;
@@ -314,7 +315,7 @@ ccl_device_forceinline void kernel_embree_filter_occluded_shadow_all_func_impl(
   /* Current implementation in Cycles assumes only single-ray intersection queries. */
   assert(args->N == 1);
 
-  RTCRay *ray = (RTCRay *)args->ray;
+  const RTCRay *ray = (RTCRay *)args->ray;
   RTCHit *hit = (RTCHit *)args->hit;
 #if EMBREE_MAJOR_VERSION >= 4
   CCLShadowContext *ctx = (CCLShadowContext *)(args->context);
@@ -367,42 +368,51 @@ ccl_device_forceinline void kernel_embree_filter_occluded_shadow_all_func_impl(
     }
   }
 
-  /* Test if we need to record this transparent intersection. */
-  const numhit_t max_record_hits = min(ctx->max_hits, numhit_t(INTEGRATOR_SHADOW_ISECT_SIZE));
-  if (ctx->num_recorded_hits < max_record_hits) {
-    /* If maximum number of hits was reached, replace the intersection with the
-     * highest distance. We want to find the N closest intersections. */
-    const numhit_t num_recorded_hits = min(ctx->num_recorded_hits, max_record_hits);
-    numhit_t isect_index = num_recorded_hits;
-    if (num_recorded_hits + 1 >= max_record_hits) {
-      float max_t = INTEGRATOR_STATE_ARRAY(ctx->isect_s, shadow_isect, 0, t);
-      numhit_t max_recorded_hit = numhit_t(0);
-
-      for (numhit_t i = numhit_t(1); i < num_recorded_hits; ++i) {
-        const float isect_t = INTEGRATOR_STATE_ARRAY(ctx->isect_s, shadow_isect, i, t);
-        if (isect_t > max_t) {
-          max_recorded_hit = i;
-          max_t = isect_t;
-        }
-      }
-
-      if (num_recorded_hits >= max_record_hits) {
-        isect_index = max_recorded_hit;
-      }
-
-      /* Limit the ray distance and stop counting hits beyond this. */
-      ray->tfar = max(current_isect.t, max_t);
-    }
-
-    integrator_state_write_shadow_isect(ctx->isect_s, &current_isect, isect_index);
-  }
+  numhit_t isect_index = ctx->num_recorded_hits;
 
   /* Always increase the number of recorded hits, even beyond the maximum,
-   * so that we can detect this and trace another ray if needed. */
+   * so that we can detect this and trace another ray if needed.
+   * More details about the related logic can be found in implementation of
+   * "shadow_intersections_has_remaining" and "integrate_transparent_shadow"
+   * functions. */
   ++ctx->num_recorded_hits;
 
   /* This tells Embree to continue tracing. */
   *args->valid = 0;
+
+  const numhit_t max_record_hits = min(ctx->max_hits, numhit_t(INTEGRATOR_SHADOW_ISECT_SIZE));
+  /* If the maximum number of hits was reached, replace the furthest intersection
+   * with a closer one so we get the N closest intersections. */
+  if (isect_index >= max_record_hits) {
+    /* When recording only N closest hits, max_t will always only decrease.
+     * So let's test if we are already not meeting criteria and can skip max_t recalculation. */
+    if (current_isect.t >= ctx->max_t) {
+      return;
+    }
+
+    float max_t = INTEGRATOR_STATE_ARRAY(ctx->isect_s, shadow_isect, 0, t);
+    numhit_t max_recorded_hit = numhit_t(0);
+
+    for (numhit_t i = numhit_t(1); i < max_record_hits; ++i) {
+      const float isect_t = INTEGRATOR_STATE_ARRAY(ctx->isect_s, shadow_isect, i, t);
+      if (isect_t > max_t) {
+        max_recorded_hit = i;
+        max_t = isect_t;
+      }
+    }
+
+    isect_index = max_recorded_hit;
+
+    /* Limit the ray distance and avoid processing hits beyond this. */
+    ctx->max_t = max_t;
+
+    /* If it's further away than max_t, we don't record this transparent intersection. */
+    if (current_isect.t >= max_t) {
+      return;
+    }
+  }
+
+  integrator_state_write_shadow_isect(ctx->isect_s, &current_isect, isect_index);
 }
 
 ccl_device_forceinline void kernel_embree_filter_occluded_local_func_impl(

source/blender/editors/include/UI_interface.h

@@ -2408,7 +2408,10 @@ void uiTemplateImage(uiLayout *layout,
                      struct PointerRNA *userptr,
                      bool compact,
                      bool multiview);
-void uiTemplateImageSettings(uiLayout *layout, struct PointerRNA *imfptr, bool color_management);
+void uiTemplateImageSettings(uiLayout *layout,
+                             struct PointerRNA *imfptr,
+                             bool color_management,
+                             bool show_z_buffer);
 void uiTemplateImageStereo3d(uiLayout *layout, struct PointerRNA *stereo3d_format_ptr);
 void uiTemplateImageViews(uiLayout *layout, struct PointerRNA *imaptr);
 void uiTemplateImageFormatViews(uiLayout *layout,

source/blender/editors/screen/screendump.c

@@ -218,7 +218,7 @@ static void screenshot_draw(bContext *UNUSED(C), wmOperator *op)
   /* image template */
   PointerRNA ptr;
   RNA_pointer_create(NULL, &RNA_ImageFormatSettings, &scd->im_format, &ptr);
-  uiTemplateImageSettings(layout, &ptr, false);
+  uiTemplateImageSettings(layout, &ptr, false, true);
 
   /* main draw call */
   uiDefAutoButsRNA(

source/blender/editors/space_image/image_buttons.c

@@ -962,7 +962,10 @@ void uiTemplateImage(uiLayout *layout,
   UI_block_funcN_set(block, NULL, NULL, NULL);
 }
 
-void uiTemplateImageSettings(uiLayout *layout, PointerRNA *imfptr, bool color_management)
+void uiTemplateImageSettings(uiLayout *layout,
+                             PointerRNA *imfptr,
+                             bool color_management,
+                             bool show_z_buffer)
 {
   ImageFormatData *imf = imfptr->data;
   ID *id = imfptr->owner_id;
@@ -1014,7 +1017,7 @@ void uiTemplateImageSettings(uiLayout *layout, PointerRNA *imfptr, bool color_ma
     uiItemR(col, imfptr, "exr_codec", 0, NULL, ICON_NONE);
   }
 
-  if (BKE_imtype_supports_zbuf(imf->imtype)) {
+  if (BKE_imtype_supports_zbuf(imf->imtype) && show_z_buffer) {
     uiItemR(col, imfptr, "use_zbuffer", 0, NULL, ICON_NONE);
   }
 

source/blender/editors/space_image/image_ops.c

@@ -2007,7 +2007,7 @@ static void image_save_as_draw(bContext *UNUSED(C), wmOperator *op)
 
   /* Image format settings. */
   RNA_pointer_create(NULL, &RNA_ImageFormatSettings, &isd->opts.im_format, &imf_ptr);
-  uiTemplateImageSettings(layout, &imf_ptr, save_as_render);
+  uiTemplateImageSettings(layout, &imf_ptr, save_as_render, true);
 
   if (!save_as_render) {
     PointerRNA linear_settings_ptr = RNA_pointer_get(&imf_ptr, "linear_colorspace_settings");

source/blender/makesrna/intern/rna_ui_api.c

@@ -1637,6 +1637,7 @@ void RNA_api_ui_layout(StructRNA *srna)
   parm = RNA_def_pointer(func, "image_settings", "ImageFormatSettings", "", "");
   RNA_def_parameter_flags(parm, PROP_NEVER_NULL, PARM_REQUIRED | PARM_RNAPTR);
   RNA_def_boolean(func, "color_management", false, "", "Show color management settings");
+  RNA_def_boolean(func, "show_z_buffer", true, "", "Show option to save z-buffer");
 
   func = RNA_def_function(srna, "template_image_stereo_3d", "uiTemplateImageStereo3d");
   RNA_def_function_ui_description(func, "User interface for setting image stereo 3d options");

source/blender/nodes/composite/nodes/node_composite_output_file.cc

@@ -305,9 +305,11 @@ static void node_composit_buts_file_output_ex(uiLayout *layout, bContext *C, Poi
   const bool multilayer = RNA_enum_get(&imfptr, "file_format") == R_IMF_IMTYPE_MULTILAYER;
   const bool is_exr = RNA_enum_get(&imfptr, "file_format") == R_IMF_IMTYPE_OPENEXR;
   const bool is_multiview = (scene->r.scemode & R_MULTIVIEW) != 0;
+  /* Unclear where to get z-information from, so deactivate it. */
+  const bool show_z_buffer = false;
 
   node_composit_buts_file_output(layout, C, ptr);
-  uiTemplateImageSettings(layout, &imfptr, true);
+  uiTemplateImageSettings(layout, &imfptr, true, show_z_buffer);
 
   /* disable stereo output for multilayer, too much work for something that no one will use */
   /* if someone asks for that we can implement it */
@@ -430,7 +432,7 @@ static void node_composit_buts_file_output_ex(uiLayout *layout, bContext *C, Poi
         const bool use_color_management = RNA_boolean_get(&active_input_ptr, "save_as_render");
 
         col = uiLayoutColumn(layout, false);
-        uiTemplateImageSettings(col, &imfptr, use_color_management);
+        uiTemplateImageSettings(col, &imfptr, use_color_management, show_z_buffer);
 
         if (is_multiview) {
           col = uiLayoutColumn(layout, false);