UI: Changes to Viewport Display UI of Volume Object and Fluid

- Density, interpolation and slicing options in Volume Object's
  Viewport Display are now not aligned to each other as they are not
  closely related.
- Changed the enum property for slicing ('Method') to a boolean
  property 'Slice' and added a sub-panel for slicing options under
  the 'Viewport Display' panel in Volume Object and Fluid for better
  clarity.
- Renamed `axis_slice_method` to `use_slice` in the python API for
  Volume Object and Fluid.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D9097

6 files changed, 77 insertions, 48 deletions

diff --git a/release/scripts/modules/rna_manual_reference.py b/release/scripts/modules/rna_manual_reference.py
index a7d338f3b53..9c4d2530674 100644
--- a/release/scripts/modules/rna_manual_reference.py
+++ b/release/scripts/modules/rna_manual_reference.py
@@ -138,7 +138,6 @@ url_manual_mapping = (
 	("bpy.types.view3doverlay.sculpt_mode_mask_opacity*", "sculpt_paint/sculpting/hide_mask.html#bpy-types-view3doverlay-sculpt-mode-mask-opacity"),
 	("bpy.ops.outliner.collection_indirect_only_clear*", "render/layers/layers.html#bpy-ops-outliner-collection-indirect-only-clear"),
 	("bpy.types.cyclesrendersettings.max_subdivisions*", "render/cycles/render_settings/subdivision.html#bpy-types-cyclesrendersettings-max-subdivisions"),
-	("bpy.types.fluiddomainsettings.axis_slice_method*", "physics/fluid/type/domain/gas/viewport_display.html#bpy-types-fluiddomainsettings-axis-slice-method"),
 	("bpy.types.fluiddomainsettings.cache_data_format*", "physics/fluid/type/domain/cache.html#bpy-types-fluiddomainsettings-cache-data-format"),
 	("bpy.types.fluiddomainsettings.cache_frame_start*", "physics/fluid/type/domain/cache.html#bpy-types-fluiddomainsettings-cache-frame-start"),
 	("bpy.types.fluiddomainsettings.cache_mesh_format*", "physics/fluid/type/domain/cache.html#bpy-types-fluiddomainsettings-cache-mesh-format"),
@@ -278,7 +277,6 @@ url_manual_mapping = (
 	("bpy.types.sequenceeditor.use_overlay_lock*", "video_editing/preview/properties.html#bpy-types-sequenceeditor-use-overlay-lock"),
 	("bpy.types.spaceuveditor.show_pixel_coords*", "editors/uv/display_panel.html#bpy-types-spaceuveditor-show-pixel-coords"),
 	("bpy.types.toolsettings.gpencil_selectmode*", "grease_pencil/selecting.html#bpy-types-toolsettings-gpencil-selectmode"),
-	("bpy.types.volumedisplay.axis_slice_method*", "modeling/volumes/properties.html#bpy-types-volumedisplay-axis-slice-method"),
 	("bpy.ops.gpencil.active_frames_delete_all*", "grease_pencil/animation/tools.html#bpy-ops-gpencil-active-frames-delete-all"),
 	("bpy.ops.gpencil.stroke_merge_by_distance*", "grease_pencil/modes/edit/grease_pencil_menu.html#bpy-ops-gpencil-stroke-merge-by-distance"),
 	("bpy.ops.object.anim_transforms_to_deltas*", "scene_layout/object/editing/apply.html#bpy-ops-object-anim-transforms-to-deltas"),
@@ -323,6 +321,7 @@ url_manual_mapping = (
 	("bpy.types.compositornodemoviedistortion*", "compositing/types/distort/movie_distortion.html#bpy-types-compositornodemoviedistortion"),
 	("bpy.types.fluiddomainsettings.use_guide*", "physics/fluid/type/domain/guides.html#bpy-types-fluiddomainsettings-use-guide"),
 	("bpy.types.fluiddomainsettings.use_noise*", "physics/fluid/type/domain/gas/noise.html#bpy-types-fluiddomainsettings-use-noise"),
+	("bpy.types.fluiddomainsettings.use_slice*", "physics/fluid/type/domain/gas/viewport_display.html#bpy-types-fluiddomainsettings-use-slice"),
 	("bpy.types.fluiddomainsettings.vorticity*", "physics/fluid/type/domain/settings.html#bpy-types-fluiddomainsettings-vorticity"),
 	("bpy.types.fluidflowsettings.flow_source*", "physics/fluid/type/flow.html#bpy-types-fluidflowsettings-flow-source"),
 	("bpy.types.fluidflowsettings.fuel_amount*", "physics/fluid/type/flow.html#bpy-types-fluidflowsettings-fuel-amount"),
@@ -575,6 +574,7 @@ url_manual_mapping = (
 	("bpy.types.toolsettings.annotation*", "interface/annotate_tool.html#bpy-types-toolsettings-annotation"),
 	("bpy.types.vertexweightmixmodifier*", "modeling/modifiers/modify/weight_mix.html#bpy-types-vertexweightmixmodifier"),
 	("bpy.types.viewlayer.use_freestyle*", "render/freestyle/view_layer.html#bpy-types-viewlayer-use-freestyle"),
+	("bpy.types.volumedisplay.use_slice*", "modeling/volumes/properties.html#bpy-types-volumedisplay-use-slice"),
 	("bpy.ops.armature.armature_layers*", "animation/armatures/bones/editing/change_layers.html#bpy-ops-armature-armature-layers"),
 	("bpy.ops.gpencil.frame_clean_fill*", "grease_pencil/modes/edit/grease_pencil_menu.html#bpy-ops-gpencil-frame-clean-fill"),
 	("bpy.ops.gpencil.stroke_subdivide*", "grease_pencil/modes/edit/stroke_menu.html#bpy-ops-gpencil-stroke-subdivide"),
diff --git a/release/scripts/startup/bl_operators/object_quick_effects.py b/release/scripts/startup/bl_operators/object_quick_effects.py
index 62d522fabd7..8ac1262645b 100644
--- a/release/scripts/startup/bl_operators/object_quick_effects.py
+++ b/release/scripts/startup/bl_operators/object_quick_effects.py
@@ -528,8 +528,8 @@ class QuickLiquid(Operator):
         # set color mapping field to show phi grid for liquid
         liquid_domain.domain_settings.color_ramp_field = 'PHI'
 
-        # set slicing method to single
-        liquid_domain.domain_settings.axis_slice_method = 'SINGLE'
+        # perform a single slice of the domain
+        liquid_domain.domain_settings.use_slice = True
 
         # set display thickness to a lower value for more detailed display of phi grids
         liquid_domain.domain_settings.display_thickness = 0.02
diff --git a/release/scripts/startup/bl_ui/properties_data_volume.py b/release/scripts/startup/bl_ui/properties_data_volume.py
index af2c94ad423..0a8bbd19b63 100644
--- a/release/scripts/startup/bl_ui/properties_data_volume.py
+++ b/release/scripts/startup/bl_ui/properties_data_volume.py
@@ -142,9 +142,6 @@ class DATA_PT_volume_viewport_display(DataButtonsPanel, Panel):
 
         volume = context.volume
         display = volume.display
-        axis_slice_method = display.axis_slice_method
-
-        do_full_slicing = (axis_slice_method == 'FULL')
 
         col = layout.column(align=True)
         col.prop(display, "wireframe_type")
@@ -152,14 +149,37 @@ class DATA_PT_volume_viewport_display(DataButtonsPanel, Panel):
         sub.active = display.wireframe_type in {'BOXES', 'POINTS'}
         sub.prop(display, "wireframe_detail", text="Detail")
 
-        col = layout.column(align=True)
+        col = layout.column()
         col.prop(display, "density")
         col.prop(display, "interpolation_method")
-        col.prop(display, "axis_slice_method")
 
-        if not do_full_slicing:
-            col.prop(display, "slice_axis")
-            col.prop(display, "slice_depth")
+
+class DATA_PT_volume_viewport_display_slicing(DataButtonsPanel, Panel):
+    bl_label = ""
+    bl_parent_id = 'DATA_PT_volume_viewport_display'
+    COMPAT_ENGINES = {'BLENDER_RENDER', 'BLENDER_EEVEE', 'BLENDER_WORKBENCH'}
+
+    def draw_header(self, context):
+        layout = self.layout
+
+        volume = context.volume
+        display = volume.display
+
+        layout.prop(display, "use_slice")
+
+    def draw(self, context):
+        layout = self.layout
+        layout.use_property_split = True
+        layout.use_property_decorate = False
+
+        volume = context.volume
+        display = volume.display
+
+        layout.active = display.use_slice
+
+        col = layout.column()
+        col.prop(display, "slice_axis")
+        col.prop(display, "slice_depth")
 
 
 class DATA_PT_custom_props_volume(DataButtonsPanel, PropertyPanel, Panel):
@@ -173,6 +193,7 @@ classes = (
     DATA_PT_volume_grids,
     DATA_PT_volume_file,
     DATA_PT_volume_viewport_display,
+    DATA_PT_volume_viewport_display_slicing,
     DATA_PT_volume_render,
     DATA_PT_custom_props_volume,
     VOLUME_UL_grids,
diff --git a/release/scripts/startup/bl_ui/properties_physics_fluid.py b/release/scripts/startup/bl_ui/properties_physics_fluid.py
index cdbd7f75193..1f5a96f2705 100644
--- a/release/scripts/startup/bl_ui/properties_physics_fluid.py
+++ b/release/scripts/startup/bl_ui/properties_physics_fluid.py
@@ -1301,9 +1301,6 @@ class PHYSICS_PT_viewport_display(PhysicButtonsPanel, Panel):
         flow = layout.grid_flow(row_major=True, columns=0, even_columns=True, even_rows=False, align=True)
 
         domain = context.fluid.domain_settings
-        axis_slice_method = domain.axis_slice_method
-
-        do_full_slicing = (axis_slice_method == 'FULL')
 
         col = flow.column(align=False)
         col.prop(domain, "display_thickness")
@@ -1314,19 +1311,43 @@ class PHYSICS_PT_viewport_display(PhysicButtonsPanel, Panel):
         if domain.use_color_ramp and domain.color_ramp_field == 'FLAGS':
             sub.enabled = False
 
-        col.prop(domain, "axis_slice_method")
-
-        if not do_full_slicing:
-            col.prop(domain, "slice_axis")
-            col.prop(domain, "slice_depth")
-            if domain.display_interpolation == 'CLOSEST' or domain.color_ramp_field == 'FLAGS':
-                col.prop(domain, "show_gridlines")
-
         col = col.column()
-        col.active = do_full_slicing
+        col.active = not domain.use_slice
         col.prop(domain, "slice_per_voxel")
 
 
+class PHYSICS_PT_viewport_display_slicing(PhysicButtonsPanel, Panel):
+    bl_label = "Slice"
+    bl_parent_id = 'PHYSICS_PT_viewport_display'
+    bl_options = {'DEFAULT_CLOSED'}
+
+    @classmethod
+    def poll(cls, context):
+        return (PhysicButtonsPanel.poll_fluid_domain(context))
+
+    def draw_header(self, context):
+        md = context.fluid.domain_settings
+
+        self.layout.prop(md, "use_slice", text="")
+
+    def draw(self, context):
+        layout = self.layout
+        layout.use_property_split = True
+
+        domain = context.fluid.domain_settings
+
+        layout.active = domain.use_slice
+
+        col = layout.column()
+        col.prop(domain, "slice_axis")
+        col.prop(domain, "slice_depth")
+
+        sub = col.column()
+        sub.prop(domain, "show_gridlines")
+
+        sub.active = domain.display_interpolation == 'CLOSEST' or domain.color_ramp_field == 'FLAGS'
+
+
 class PHYSICS_PT_viewport_display_color(PhysicButtonsPanel, Panel):
     bl_label = "Grid Display"
     bl_parent_id = 'PHYSICS_PT_viewport_display'
@@ -1408,7 +1429,8 @@ class PHYSICS_PT_viewport_display_advanced(PhysicButtonsPanel, Panel):
 
     @classmethod
     def poll(cls, context):
-        return PhysicButtonsPanel.poll_fluid_domain(context) and context.fluid.domain_settings.show_gridlines
+        domain = context.fluid.domain_settings
+        return PhysicButtonsPanel.poll_fluid_domain(context) and domain.use_slice and domain.show_gridlines
 
     def draw(self, context):
         layout = self.layout
@@ -1416,6 +1438,8 @@ class PHYSICS_PT_viewport_display_advanced(PhysicButtonsPanel, Panel):
 
         domain = context.fluid.domain_settings
 
+        layout.active = domain.display_interpolation == 'CLOSEST' or domain.color_ramp_field == 'FLAGS'
+
         col = layout.column()
         col.prop(domain, "gridlines_color_field", text="Color Gridlines")
 
@@ -1456,6 +1480,7 @@ classes = (
     PHYSICS_PT_flow_initial_velocity,
     PHYSICS_PT_flow_texture,
     PHYSICS_PT_viewport_display,
+    PHYSICS_PT_viewport_display_slicing,
     PHYSICS_PT_viewport_display_color,
     PHYSICS_PT_viewport_display_debug,
     PHYSICS_PT_viewport_display_advanced,
diff --git a/source/blender/makesrna/intern/rna_fluid.c b/source/blender/makesrna/intern/rna_fluid.c
index 9d7359bb8f0..cb64d81533f 100644
--- a/source/blender/makesrna/intern/rna_fluid.c
+++ b/source/blender/makesrna/intern/rna_fluid.c
@@ -1306,12 +1306,6 @@ static void rna_def_fluid_domain_settings(BlenderRNA *brna)
       {0, NULL, 0, NULL, NULL},
   };
 
-  static const EnumPropertyItem axis_slice_method_items[] = {
-      {AXIS_SLICE_FULL, "FULL", 0, "Full", "Slice the whole domain object"},
-      {AXIS_SLICE_SINGLE, "SINGLE", 0, "Single", "Perform a single slice of the domain object"},
-      {0, NULL, 0, NULL, NULL},
-  };
-
   static const EnumPropertyItem interp_method_item[] = {
       {FLUID_DISPLAY_INTERP_LINEAR, "LINEAR", 0, "Linear", "Good smoothness and speed"},
       {FLUID_DISPLAY_INTERP_CUBIC,
@@ -2439,10 +2433,9 @@ static void rna_def_fluid_domain_settings(BlenderRNA *brna)
 
   /* display settings */
 
-  prop = RNA_def_property(srna, "axis_slice_method", PROP_ENUM, PROP_NONE);
-  RNA_def_property_enum_sdna(prop, NULL, "axis_slice_method");
-  RNA_def_property_enum_items(prop, axis_slice_method_items);
-  RNA_def_property_ui_text(prop, "Method", "");
+  prop = RNA_def_property(srna, "use_slice", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "axis_slice_method", AXIS_SLICE_SINGLE);
+  RNA_def_property_ui_text(prop, "Slice", "Perform a single slice of the domain object");
   RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, NULL);
 
   prop = RNA_def_property(srna, "slice_axis", PROP_ENUM, PROP_NONE);
diff --git a/source/blender/makesrna/intern/rna_volume.c b/source/blender/makesrna/intern/rna_volume.c
index 054f108099b..8a5e25c52fb 100644
--- a/source/blender/makesrna/intern/rna_volume.c
+++ b/source/blender/makesrna/intern/rna_volume.c
@@ -406,16 +406,6 @@ static void rna_def_volume_display(BlenderRNA *brna)
       {0, NULL, 0, NULL, NULL},
   };
 
-  static const EnumPropertyItem axis_slice_method_items[] = {
-      {VOLUME_AXIS_SLICE_FULL, "FULL", 0, "Full", "Slice the whole domain object"},
-      {VOLUME_AXIS_SLICE_SINGLE,
-       "SINGLE",
-       0,
-       "Single",
-       "Perform a single slice of the domain object"},
-      {0, NULL, 0, NULL, NULL},
-  };
-
   static const EnumPropertyItem axis_slice_position_items[] = {
       {VOLUME_SLICE_AXIS_AUTO,
        "AUTO",
@@ -444,9 +434,9 @@ static void rna_def_volume_display(BlenderRNA *brna)
       prop, "Interpolation", "Interpolation method to use for volumes in solid mode");
   RNA_def_property_update(prop, 0, "rna_Volume_update_display");
 
-  prop = RNA_def_property(srna, "axis_slice_method", PROP_ENUM, PROP_NONE);
-  RNA_def_property_enum_items(prop, axis_slice_method_items);
-  RNA_def_property_ui_text(prop, "Method", "");
+  prop = RNA_def_property(srna, "use_slice", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "axis_slice_method", VOLUME_AXIS_SLICE_SINGLE);
+  RNA_def_property_ui_text(prop, "Slice", "Perform a single slice of the domain object");
   RNA_def_property_update(prop, 0, "rna_Volume_update_display");
 
   prop = RNA_def_property(srna, "slice_axis", PROP_ENUM, PROP_NONE);