intern/cycles/blender/addon/ui.py

@@ -1078,16 +1078,17 @@ class CYCLES_CAMERA_PT_dof(CyclesButtonsPanel, Panel):
         dof = cam.dof
         layout.active = dof.use_dof
 
-        split = layout.split()
-
-        col = split.column()
-        col.prop(dof, "focus_object", text="Focus Object")
-        if dof.focus_object and dof.focus_object.type == 'ARMATURE':
-            col.prop_search(dof, "focus_subtarget", dof.focus_object.data, "bones", text="Focus Bone")
-
-        sub = col.row()
-        sub.active = dof.focus_object is None
-        sub.prop(dof, "focus_distance", text="Distance")
+        col = layout.column()
+        if dof.focus_collection is None:
+            col.prop(dof, "focus_object", text="Focus on Object")
+            if dof.focus_object and dof.focus_object.type == 'ARMATURE':
+                col.prop_search(dof, "focus_subtarget", dof.focus_object.data, "bones", text="Focus on Bone")
+        if dof.focus_object is None:
+            sub = col.column()
+            sub.prop(dof, "focus_collection", text="Focus on Collection")
+        if dof.focus_object is None and dof.focus_collection is None:
+            sub = sub.column()
+            sub.prop(dof, "focus_distance", text="Focus Distance")
 
 
 class CYCLES_CAMERA_PT_dof_aperture(CyclesButtonsPanel, Panel):

intern/cycles/blender/camera.cpp

@@ -135,17 +135,49 @@ static void blender_camera_init(BlenderCamera *bcam, BL::RenderSettings &b_rende
   bcam->full_height = bcam->render_height;
 }
 
+static void sum_obj_positions(float3 &pos, int &count, BL::Collection &coll)
+{
+  for (BL::Object obj : coll.objects) {
+    Transform dofmat = get_transform(obj.matrix_world());
+    float3 curr = transform_get_column(&dofmat, 3);
+    pos.x += curr.x;
+    pos.y += curr.y;
+    pos.z += curr.z;
+    count += 1;
+  }
+  for (BL::Collection child : coll.children) {
+    sum_obj_positions(pos, count, child);
+  }
+}
+
 static float blender_camera_focal_distance(BL::RenderEngine &b_engine,
                                            BL::Object &b_ob,
                                            BL::Camera &b_camera,
                                            BlenderCamera *bcam)
 {
   BL::Object b_dof_object = b_camera.dof().focus_object();
+  BL::Collection b_dof_collection = b_camera.dof().focus_collection();
 
-  if (!b_dof_object) {
+  if (!b_dof_object && !b_dof_collection) {
     return b_camera.dof().focus_distance();
   }
 
+  if (b_dof_collection) {
+    int count = 0;
+    float3 pos = {};
+    sum_obj_positions(pos, count, b_dof_collection);
+    float den = static_cast<float>(count);
+    pos.x /= den;
+    pos.y /= den;
+    pos.z /= den;
+    BL::Array<float, 16> b_ob_matrix;
+    b_engine.camera_model_matrix(b_ob, bcam->use_spherical_stereo, b_ob_matrix);
+    Transform obmat = transform_clear_scale(get_transform(b_ob_matrix));
+    float3 view_dir = normalize(transform_get_column(&obmat, 2));
+    float3 dof_dir = transform_get_column(&obmat, 3) - pos;
+    return fabsf(dot(view_dir, dof_dir));
+  }
+
   Transform dofmat = get_transform(b_dof_object.matrix_world());
 
   string focus_subtarget = b_camera.dof().focus_subtarget();

scripts/startup/bl_ui/properties_data_camera.py

@@ -251,12 +251,16 @@ class DATA_PT_camera_dof(CameraButtonsPanel, Panel):
         layout.active = dof.use_dof
 
         col = layout.column()
-        col.prop(dof, "focus_object", text="Focus on Object")
-        if dof.focus_object and dof.focus_object.type == 'ARMATURE':
-            col.prop_search(dof, "focus_subtarget", dof.focus_object.data, "bones", text="Focus on Bone")
-        sub = col.column()
-        sub.active = (dof.focus_object is None)
-        sub.prop(dof, "focus_distance", text="Focus Distance")
+        if dof.focus_collection is None:
+            col.prop(dof, "focus_object", text="Focus on Object")
+            if dof.focus_object and dof.focus_object.type == 'ARMATURE':
+                col.prop_search(dof, "focus_subtarget", dof.focus_object.data, "bones", text="Focus on Bone")
+        if dof.focus_object is None:
+            sub = col.column()
+            sub.prop(dof, "focus_collection", text="Focus on Collection")
+        if dof.focus_object is None and dof.focus_collection is None:
+            sub = sub.column()
+            sub.prop(dof, "focus_distance", text="Focus Distance")
 
 
 class DATA_PT_camera_dof_aperture(CameraButtonsPanel, Panel):

scripts/startup/bl_ui/space_view3d.py

@@ -2895,7 +2895,7 @@ class VIEW3D_MT_object_context_menu(Menu):
                 props.input_scale = 0.01
                 props.header_text = rpt_("Camera Lens Scale: %.3f")
 
-            if not obj.data.dof.focus_object:
+            if not obj.data.dof.focus_object and not obj.data.dof.focus_collection:
                 if view and view.camera == obj and view.region_3d.view_perspective == 'CAMERA':
                     props = layout.operator("ui.eyedropper_depth", text="DOF Distance (Pick)")
                 else:

source/blender/blenkernel/intern/camera.cc

@@ -15,6 +15,7 @@
 
 #include "DNA_ID.h"
 #include "DNA_camera_types.h"
+#include "DNA_collection_types.h"
 #include "DNA_defaults.h"
 #include "DNA_light_types.h"
 #include "DNA_object_types.h"
@@ -101,6 +102,7 @@ static void camera_foreach_id(ID *id, LibraryForeachIDData *data)
   const int flag = BKE_lib_query_foreachid_process_flags_get(data);
 
   BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, camera->dof.focus_object, IDWALK_CB_NOP);
+  BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, camera->dof.focus_collection, IDWALK_CB_NOP);
   LISTBASE_FOREACH (CameraBGImage *, bgpic, &camera->bg_images) {
     BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, bgpic->ima, IDWALK_CB_USER);
     BKE_LIB_FOREACHID_PROCESS_IDSUPER(data, bgpic->clip, IDWALK_CB_USER);
@@ -276,12 +278,50 @@ void *BKE_camera_add(Main *bmain, const char *name)
   return cam;
 }
 
+static void sum_obj_positions(float pos[3], int *count, Collection *c)
+{
+  ListBase *gobject = &(c->gobject);
+  ListBase *children = &(c->children);
+  *count += BLI_listbase_count(gobject);
+  LISTBASE_FOREACH (LinkData *, current, gobject) {
+    Object *o = static_cast<Object *>(current->data);
+    const blender::float3 &cpos = o->object_to_world().location();
+    add_v3_v3v3(pos, pos, cpos);
+    printf("Name: %s, Pos: %f, %f, %f, Total: %f, %f, %f\n",
+           o->id.name,
+           cpos.x,
+           cpos.y,
+           cpos.z,
+           pos[0],
+           pos[1],
+           pos[2]);  // DEBUG
+  }
+  LISTBASE_FOREACH (LinkData *, current, children) {
+    Collection *child = static_cast<Collection *>(current->data);
+    sum_obj_positions(pos, count, child);
+  }
+}
+
 float BKE_camera_object_dof_distance(const Object *ob)
 {
   const Camera *cam = (const Camera *)ob->data;
   if (ob->type != OB_CAMERA) {
     return 0.0f;
   }
+  if (cam->dof.focus_collection) {
+    float view_dir[3], dof_dir[3];
+    normalize_v3_v3(view_dir, ob->object_to_world().ptr()[2]);
+
+    float pos[3] = {0.0f, 0.0f, 0.0f};
+    int count = 0;
+    sum_obj_positions(pos, &count, cam->dof.focus_collection);
+    float scale = 1.0f / static_cast<float>(count);
+    mul_v3_fl(pos, scale);
+    printf("Nobjects: %d, AVG Pos: %f, %f, %f\n", count, pos[0], pos[1], pos[2]);  // DEBUG
+
+    sub_v3_v3v3(dof_dir, ob->object_to_world().location(), pos);
+    return fabsf(dot_v3v3(view_dir, dof_dir));
+  }
   if (cam->dof.focus_object) {
     float view_dir[3], dof_dir[3];
     normalize_v3_v3(view_dir, ob->object_to_world().ptr()[2]);

source/blender/depsgraph/intern/builder/deg_builder_nodes.cc

@@ -1874,6 +1874,9 @@ void DepsgraphNodeBuilder::build_camera(Camera *camera)
   if (camera->dof.focus_object != nullptr) {
     build_object(-1, camera->dof.focus_object, DEG_ID_LINKED_INDIRECTLY, false);
   }
+  if (camera->dof.focus_collection != nullptr) {
+    build_collection(nullptr, camera->dof.focus_collection);
+  }
 }
 
 void DepsgraphNodeBuilder::build_light(Light *lamp)

source/blender/editors/object/object_relations.cc

@@ -1888,6 +1888,7 @@ static void single_obdata_users(
                                           nullptr,
                                           LIB_ID_COPY_DEFAULT | LIB_ID_COPY_ACTIONS)));
             ID_NEW_REMAP(cam->dof.focus_object);
+            ID_NEW_REMAP(cam->dof.focus_collection);
             break;
           case OB_MESH:
             /* Needed to remap texcomesh below. */

source/blender/makesdna/DNA_camera_types.h

@@ -51,6 +51,7 @@ typedef struct CameraBGImage {
 typedef struct CameraDOFSettings {
   /** Focal distance for depth of field. */
   struct Object *focus_object;
+  struct Collection *focus_collection;
   char focus_subtarget[64];
   float focus_distance;
   float aperture_fstop;

source/blender/makesrna/intern/rna_camera.cc

@@ -522,6 +522,15 @@ static void rna_def_camera_dof_settings_data(BlenderRNA *brna)
       prop, "Focus Object", "Use this object to define the depth of field focal point");
   RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_Camera_dependency_update");
 
+  prop = RNA_def_property(srna, "focus_collection", PROP_POINTER, PROP_NONE);
+  RNA_def_property_struct_type(prop, "Collection");
+  RNA_def_property_pointer_sdna(prop, nullptr, "focus_collection");
+  RNA_def_property_flag(prop, PROP_EDITABLE);
+  RNA_def_property_override_flag(prop, PROPOVERRIDE_OVERRIDABLE_LIBRARY);
+  RNA_def_property_ui_text(
+      prop, "Focus Collection", "Use this object to define the depth of field focal point");
+  RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_Camera_dependency_update");
+
   prop = RNA_def_property(srna, "focus_subtarget", PROP_STRING, PROP_NONE);
   RNA_def_property_string_sdna(prop, nullptr, "focus_subtarget");
   RNA_def_property_ui_text(