Grease Pencil: Add LineArt modifier

This adds the LineArt grease pencil modifier.

It takes objects or collections as input and generates various grease
pencil lines from these objects with the help of the active scene
camera. For example it can generate contour lines, intersection lines
and crease lines to name a few.

This is really useful as artists can then use 3D meshes to automatically
generate grease pencil lines for characters, enviroments or other
visualization purposes.

These lines can then be baked and edited as regular grease pencil lines.

Reviewed By: Sebastian Parborg, Antonio Vazquez, Matias Mendiola

Differential Revision: http://developer.blender.org/D8758

1 files changed, 284 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_gpencil_modifier.c b/source/blender/makesrna/intern/rna_gpencil_modifier.c
index 71d5a53adb2..b84fcf4cf7c 100644
--- a/source/blender/makesrna/intern/rna_gpencil_modifier.c
+++ b/source/blender/makesrna/intern/rna_gpencil_modifier.c
@@ -88,6 +88,11 @@ const EnumPropertyItem rna_enum_object_greasepencil_modifier_type_items[] = {
      ICON_MOD_SUBSURF,
      "Subdivide",
      "Subdivide stroke adding more control points"},
+    {eGpencilModifierType_Lineart,
+     "GP_LINEART",
+     ICON_MOD_EDGESPLIT,
+     "Line Art",
+     "Generate Line Art strokes from selected source"},
     {0, "", 0, N_("Deform"), ""},
     {eGpencilModifierType_Armature,
      "GP_ARMATURE",
@@ -241,6 +246,8 @@ static StructRNA *rna_GpencilModifier_refine(struct PointerRNA *ptr)
       return &RNA_MultiplyGpencilModifier;
     case eGpencilModifierType_Texture:
       return &RNA_TextureGpencilModifier;
+    case eGpencilModifierType_Lineart:
+      return &RNA_LineartGpencilModifier;
       /* Default */
     case eGpencilModifierType_None:
     case NUM_GREASEPENCIL_MODIFIER_TYPES:
@@ -311,6 +318,7 @@ RNA_GP_MOD_VGROUP_NAME_SET(Offset, vgname);
 RNA_GP_MOD_VGROUP_NAME_SET(Armature, vgname);
 RNA_GP_MOD_VGROUP_NAME_SET(Texture, vgname);
 RNA_GP_MOD_VGROUP_NAME_SET(Tint, vgname);
+RNA_GP_MOD_VGROUP_NAME_SET(Lineart, vgname);
 
 #  undef RNA_GP_MOD_VGROUP_NAME_SET
 
@@ -2305,6 +2313,281 @@ static void rna_def_modifier_gpenciltexture(BlenderRNA *brna)
   RNA_def_property_update(prop, 0, "rna_GpencilModifier_dependency_update");
 }
 
+static void rna_def_modifier_gpencillineart(BlenderRNA *brna)
+{
+  StructRNA *srna;
+  PropertyRNA *prop;
+
+  static const EnumPropertyItem modifier_lineart_source_type[] = {
+      {LRT_SOURCE_COLLECTION, "COLLECTION", 0, "Collection", ""},
+      {LRT_SOURCE_OBJECT, "OBJECT", 0, "Object", ""},
+      {LRT_SOURCE_SCENE, "SCENE", 0, "Scene", ""},
+      {0, NULL, 0, NULL, NULL},
+  };
+
+  srna = RNA_def_struct(brna, "LineartGpencilModifier", "GpencilModifier");
+  RNA_def_struct_ui_text(
+      srna, "Line Art Modifier", "Generate Line Art strokes from selected source");
+  RNA_def_struct_sdna(srna, "LineartGpencilModifierData");
+  RNA_def_struct_ui_icon(srna, ICON_MOD_EDGESPLIT);
+
+  prop = RNA_def_property(srna, "fuzzy_intersections", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "calculation_flags", LRT_INTERSECTION_AS_CONTOUR);
+  RNA_def_property_ui_text(prop,
+                           "Intersection With Contour",
+                           "Treat intersection and contour lines as if they were the same type so "
+                           "they can be chained together");
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "fuzzy_everything", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "calculation_flags", LRT_EVERYTHING_AS_CONTOUR);
+  RNA_def_property_ui_text(
+      prop, "All Lines", "Treat all lines as the same line type so they can be chained together");
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "allow_duplication", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "calculation_flags", LRT_ALLOW_DUPLI_OBJECTS);
+  RNA_def_property_ui_text(
+      prop,
+      "Instanced Objects",
+      "Allow particle objects and face/vertiex duplication to show in line art");
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "allow_overlapping_edges", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "calculation_flags", LRT_ALLOW_OVERLAPPING_EDGES);
+  RNA_def_property_ui_text(prop,
+                           "Handle Overlapping Edges",
+                           "Allow lines from edge split to show properly, may run slower");
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "allow_clipping_boundaries", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "calculation_flags", LRT_ALLOW_CLIPPING_BOUNDARIES);
+  RNA_def_property_ui_text(
+      prop, "Clipping Boundaries", "Allow lines on near/far clipping plane to be shown");
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "crease_threshold", PROP_FLOAT, PROP_ANGLE);
+  RNA_def_property_range(prop, 0, DEG2RAD(180.0f));
+  RNA_def_property_ui_range(prop, 0.0f, DEG2RAD(180.0f), 0.01f, 1);
+  RNA_def_property_ui_text(
+      prop, "Crease Threshold", "Angles smaller than this will be treated as creases");
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "angle_splitting_threshold", PROP_FLOAT, PROP_ANGLE);
+  RNA_def_property_ui_text(
+      prop, "Angle Splitting", "Angle in screen space below which a stroke is split in two");
+  /*  Don't allow value very close to PI, or we get a lot of small segments.*/
+  RNA_def_property_ui_range(prop, 0.0f, DEG2RAD(179.5f), 0.01f, 1);
+  RNA_def_property_range(prop, 0.0f, DEG2RAD(180.0f));
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "remove_doubles", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "calculation_flags", LRT_REMOVE_DOUBLES);
+  RNA_def_property_ui_text(
+      prop, "Remove Doubles", "Remove doubles when line art is loading geometries");
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "chaining_geometry_threshold", PROP_FLOAT, PROP_DISTANCE);
+  RNA_def_property_ui_text(prop,
+                           "Geometry Threshold",
+                           "Segments where their geometric distance between them lower than this "
+                           "will be chained together");
+  RNA_def_property_ui_range(prop, 0.0f, 0.5f, 0.001f, 3);
+  RNA_def_property_range(prop, 0.0f, 0.5f);
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "chaining_image_threshold", PROP_FLOAT, PROP_DISTANCE);
+  RNA_def_property_ui_text(
+      prop,
+      "Image Threshold",
+      "Segments with an image distance smaller than this will be chained together");
+  RNA_def_property_ui_range(prop, 0.0f, 0.3f, 0.001f, 4);
+  RNA_def_property_range(prop, 0.0f, 0.3f);
+  RNA_def_property_update(prop, NC_SCENE, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "source_type", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_items(prop, modifier_lineart_source_type);
+  RNA_def_property_ui_text(prop, "Source Type", "Lineart stroke source type");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_dependency_update");
+
+  prop = RNA_def_property(srna, "source_object", PROP_POINTER, PROP_NONE);
+  RNA_def_property_flag(prop, PROP_EDITABLE | PROP_ID_SELF_CHECK);
+  RNA_def_property_struct_type(prop, "Object");
+  RNA_def_property_override_flag(prop, PROPOVERRIDE_OVERRIDABLE_LIBRARY);
+  RNA_def_property_ui_text(
+      prop, "Source Object", "Source object that this modifier grabs data from");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_dependency_update");
+
+  prop = RNA_def_property(srna, "source_collection", PROP_POINTER, PROP_NONE);
+  RNA_def_property_flag(prop, PROP_EDITABLE | PROP_ID_SELF_CHECK);
+  RNA_def_property_struct_type(prop, "Collection");
+  RNA_def_property_override_flag(prop, PROPOVERRIDE_OVERRIDABLE_LIBRARY);
+  RNA_def_property_ui_text(
+      prop, "Source Collection", "Source collection that this modifier uses data from");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_dependency_update");
+
+  /* types */
+  prop = RNA_def_property(srna, "use_contour", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "line_types", LRT_EDGE_FLAG_CONTOUR);
+  RNA_def_property_ui_text(prop, "Use Contour", "Include contour lines in the result");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "use_crease", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "line_types", LRT_EDGE_FLAG_CREASE);
+  RNA_def_property_ui_text(prop, "Use Crease", "Include sharp edges in the result");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "use_material", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "line_types", LRT_EDGE_FLAG_MATERIAL);
+  RNA_def_property_ui_text(
+      prop, "Use Material", "Include material separation lines in the result");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "use_edge_mark", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "line_types", LRT_EDGE_FLAG_EDGE_MARK);
+  RNA_def_property_ui_text(prop, "Use Edge Mark", "Include freestyle edge marks in the result");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "use_intersection", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "line_types", LRT_EDGE_FLAG_INTERSECTION);
+  RNA_def_property_ui_text(prop, "Use Intersection", "Include intersection lines in the result");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "use_multiple_levels", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "use_multiple_levels", 0);
+  RNA_def_property_ui_text(
+      prop, "Use Multiple Levels", "Select lines from multiple occlusion levels");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "level_start", PROP_INT, PROP_NONE);
+  RNA_def_property_ui_text(
+      prop, "Level Start", "Minimum level of occlusion level that gets selected");
+  RNA_def_property_range(prop, 0, 128);
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "level_end", PROP_INT, PROP_NONE);
+  RNA_def_property_ui_text(
+      prop, "Level End", "Maximum level of occlusion level that gets selected");
+  RNA_def_property_range(prop, 0, 128);
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "target_material", PROP_POINTER, PROP_NONE);
+  RNA_def_property_flag(prop, PROP_EDITABLE | PROP_ID_SELF_CHECK);
+  RNA_def_property_struct_type(prop, "Material");
+  RNA_def_property_override_flag(prop, PROPOVERRIDE_OVERRIDABLE_LIBRARY);
+  RNA_def_property_ui_text(
+      prop, "Target Material", "Grease Pencil material assigned to the generated strokes");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "target_layer", PROP_STRING, PROP_NONE);
+  RNA_def_property_ui_text(
+      prop, "Target Layer", "Grease Pencil layer assigned to the generated strokes");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "source_vertex_group", PROP_STRING, PROP_NONE);
+  RNA_def_property_ui_text(
+      prop,
+      "Source Vertex Group",
+      "Matches the beginning of vertex group names from mesh objects, match all when left empty");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "vertex_group", PROP_STRING, PROP_NONE);
+  RNA_def_property_string_sdna(prop, NULL, "vgname");
+  RNA_def_property_string_funcs(prop, NULL, NULL, "rna_LineartGpencilModifier_vgname_set");
+  RNA_def_property_ui_text(prop, "Vertex Group", "Vertex group name for selected strokes");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "invert_source_vertex_group", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flags", LRT_GPENCIL_INVERT_SOURCE_VGROUP);
+  RNA_def_property_ui_text(prop, "Invert Source", "Invert source vertex group values");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "match_output_vertex_group", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flags", LRT_GPENCIL_MATCH_OUTPUT_VGROUP);
+  RNA_def_property_ui_text(prop, "Match Output", "Match output vertex group");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "soft_selection", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flags", LRT_GPENCIL_SOFT_SELECTION);
+  RNA_def_property_ui_text(
+      prop, "Soft selection", "Preserve original vertex weight instead of clipping to 0/1");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "is_baked", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flags", LRT_GPENCIL_IS_BAKED);
+  RNA_def_property_ui_text(prop, "Is Baked", "This modifier has baked data");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "thickness", PROP_INT, PROP_NONE);
+  RNA_def_property_ui_text(prop, "Thickness", "The thickness that used to generate strokes");
+  RNA_def_property_ui_range(prop, 1, 100, 1, 1);
+  RNA_def_property_range(prop, 1, 200);
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "opacity", PROP_FLOAT, PROP_FACTOR);
+  RNA_def_property_ui_text(prop, "Opacity", "The strength value used to generate strokes");
+  RNA_def_property_ui_range(prop, 0.0f, 1.0f, 0.01f, 2);
+  RNA_def_property_range(prop, 0.0f, 1.0f);
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "pre_sample_length", PROP_FLOAT, PROP_NONE);
+  RNA_def_property_ui_text(prop, "Pre Sample Length", "Sample strokes before sending out");
+  RNA_def_property_ui_range(prop, 0.0f, 1.0f, 0.01f, 2);
+  RNA_def_property_range(prop, 0.0f, 1.0f);
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "use_transparency", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_flags", LRT_GPENCIL_TRANSPARENCY_ENABLE);
+  RNA_def_property_ui_text(
+      prop, "Use Transparency", "Use transparency mask from this material in Line Art");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "transparency_match", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_flags", LRT_GPENCIL_TRANSPARENCY_MATCH);
+  RNA_def_property_ui_text(prop, "Match Transparency", "Match all transparency bits");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "transparency_mask_0", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_mask", 1 << 0);
+  RNA_def_property_ui_text(prop, "Mask 0", "Mask bit 0");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "transparency_mask_1", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_mask", 1 << 1);
+  RNA_def_property_ui_text(prop, "Mask 1", "Mask bit 1");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "transparency_mask_2", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_mask", 1 << 2);
+  RNA_def_property_ui_text(prop, "Mask 2", "Mask bit 2");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "transparency_mask_3", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_mask", 1 << 3);
+  RNA_def_property_ui_text(prop, "Mask 3", "Mask bit 3");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "transparency_mask_4", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_mask", 1 << 4);
+  RNA_def_property_ui_text(prop, "Mask 4", "Mask bit 4");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "transparency_mask_5", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_mask", 1 << 5);
+  RNA_def_property_ui_text(prop, "Mask 5", "Mask bit 5");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "transparency_mask_6", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_mask", 1 << 6);
+  RNA_def_property_ui_text(prop, "mask 6", "Mask bit 6");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "transparency_mask_7", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "transparency_mask", 1 << 7);
+  RNA_def_property_ui_text(prop, "Mask 7", "Mask bit 7");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+}
+
 void RNA_def_greasepencil_modifier(BlenderRNA *brna)
 {
   StructRNA *srna;
@@ -2379,6 +2662,7 @@ void RNA_def_greasepencil_modifier(BlenderRNA *brna)
   rna_def_modifier_gpencilarmature(brna);
   rna_def_modifier_gpencilmultiply(brna);
   rna_def_modifier_gpenciltexture(brna);
+  rna_def_modifier_gpencillineart(brna);
 }
 
 #endif