Add Voxel Mode to the Remesh modifier

This adds the Voxel Mode to the current remesh modifier. It works
exactly the same way as the voxel remesh operator and uses the same
properties to control the remeshing. We can exand this with more options
in the future (fix poles, reprojection...)

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D7292

5 files changed, 101 insertions, 37 deletions

diff --git a/release/scripts/startup/bl_ui/properties_data_modifier.py b/release/scripts/startup/bl_ui/properties_data_modifier.py
index e5ea1a94945..cbcd6e2b614 100644
--- a/release/scripts/startup/bl_ui/properties_data_modifier.py
+++ b/release/scripts/startup/bl_ui/properties_data_modifier.py
@@ -1317,17 +1317,22 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
         layout.prop(md, "mode")
 
         row = layout.row()
-        row.prop(md, "octree_depth")
-        row.prop(md, "scale")
+        if md.mode == 'VOXEL':
+            layout.prop(md, "voxel_size")
+            layout.prop(md, "adaptivity")
+        else: 
+            row.prop(md, "octree_depth")
+            row.prop(md, "scale")
 
-        if md.mode == 'SHARP':
-            layout.prop(md, "sharpness")
+            if md.mode == 'SHARP':
+                layout.prop(md, "sharpness")
+
+            layout.prop(md, "use_remove_disconnected")
+            row = layout.row()
+            row.active = md.use_remove_disconnected
+            row.prop(md, "threshold")
 
         layout.prop(md, "use_smooth_shade")
-        layout.prop(md, "use_remove_disconnected")
-        row = layout.row()
-        row.active = md.use_remove_disconnected
-        row.prop(md, "threshold")
 
     @staticmethod
     def vertex_weight_mask(layout, ob, md):
diff --git a/source/blender/blenloader/intern/versioning_280.c b/source/blender/blenloader/intern/versioning_280.c
index 50b1e385dd4..b3c0473e173 100644
--- a/source/blender/blenloader/intern/versioning_280.c
+++ b/source/blender/blenloader/intern/versioning_280.c
@@ -4878,5 +4878,18 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
    */
   {
     /* Keep this block, even when empty. */
+
+    /* Remesh Modifier Voxel Mode. */
+    if (!DNA_struct_elem_find(fd->filesdna, "RemeshModifierData", "float", "voxel_size")) {
+      for (Object *ob = bmain->objects.first; ob; ob = ob->id.next) {
+        for (ModifierData *md = ob->modifiers.first; md; md = md->next) {
+          if (md->type == eModifierType_Remesh) {
+            RemeshModifierData *rmd = (RemeshModifierData *)md;
+            rmd->voxel_size = 0.1f;
+            rmd->adaptivity = 0.0f;
+          }
+        }
+      }
+    }
   }
 }
diff --git a/source/blender/makesdna/DNA_modifier_types.h b/source/blender/makesdna/DNA_modifier_types.h
index 74cb72a1fae..855bf8434be 100644
--- a/source/blender/makesdna/DNA_modifier_types.h
+++ b/source/blender/makesdna/DNA_modifier_types.h
@@ -1608,6 +1608,8 @@ typedef enum eRemeshModifierMode {
   MOD_REMESH_MASS_POINT = 1,
   /* keeps sharp edges */
   MOD_REMESH_SHARP_FEATURES = 2,
+  /* Voxel remesh */
+  MOD_REMESH_VOXEL = 3,
 } eRemeshModifierMode;
 
 typedef struct RemeshModifierData {
@@ -1623,10 +1625,13 @@ typedef struct RemeshModifierData {
 
   /* octree depth */
   char depth;
-
   char flag;
   char mode;
   char _pad;
+
+  /* OpenVDB Voxel remesh properties. */
+  float voxel_size;
+  float adaptivity;
 } RemeshModifierData;
 
 /* Skin modifier */
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index 455fb1c50c9..d2eaa9538ff 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -5128,6 +5128,11 @@ static void rna_def_modifier_remesh(BlenderRNA *brna)
        0,
        "Sharp",
        "Output a surface that reproduces sharp edges and corners from the input mesh"},
+      {MOD_REMESH_VOXEL,
+       "VOXEL",
+       0,
+       "Voxel",
+       "Output a mesh corresponding to the volume of the original mesh"},
       {0, NULL, 0, NULL, NULL},
   };
 
@@ -5181,6 +5186,25 @@ static void rna_def_modifier_remesh(BlenderRNA *brna)
       "edges closer to the input");
   RNA_def_property_update(prop, 0, "rna_Modifier_update");
 
+  prop = RNA_def_property(srna, "voxel_size", PROP_FLOAT, PROP_DISTANCE);
+  RNA_def_property_float_sdna(prop, NULL, "voxel_size");
+  RNA_def_property_ui_range(prop, 0.0001, 2, 0.1, 3);
+  RNA_def_property_ui_text(prop,
+                           "Voxel Size",
+                           "Size of the voxel in object space used for volume evaluation. Lower "
+                           "values preserve finer details");
+  RNA_def_property_update(prop, 0, "rna_Modifier_update");
+
+  prop = RNA_def_property(srna, "adaptivity", PROP_FLOAT, PROP_DISTANCE);
+  RNA_def_property_float_sdna(prop, NULL, "adaptivity");
+  RNA_def_property_ui_range(prop, 0, 1, 0.1, 3);
+  RNA_def_property_ui_text(
+      prop,
+      "Adaptivity",
+      "Reduces the final face count by simplifying geometry where detail is not needed, "
+      "generating triangles. A value greater than 0 disables Fix Poles");
+  RNA_def_property_update(prop, 0, "rna_Modifier_update");
+
   prop = RNA_def_property(srna, "use_remove_disconnected", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_boolean_sdna(prop, NULL, "flag", MOD_REMESH_FLOOD_FILL);
   RNA_def_property_ui_text(prop, "Remove Disconnected Pieces", "");
diff --git a/source/blender/modifiers/intern/MOD_remesh.c b/source/blender/modifiers/intern/MOD_remesh.c
index 3300cda947c..2fa8dc973a1 100644
--- a/source/blender/modifiers/intern/MOD_remesh.c
+++ b/source/blender/modifiers/intern/MOD_remesh.c
@@ -34,6 +34,7 @@
 #include "MOD_modifiertypes.h"
 
 #include "BKE_mesh.h"
+#include "BKE_mesh_remesh_voxel.h"
 #include "BKE_mesh_runtime.h"
 
 #include <assert.h>
@@ -54,8 +55,10 @@ static void initData(ModifierData *md)
   rmd->depth = 4;
   rmd->hermite_num = 1;
   rmd->flag = MOD_REMESH_FLOOD_FILL;
-  rmd->mode = MOD_REMESH_SHARP_FEATURES;
+  rmd->mode = MOD_REMESH_VOXEL;
   rmd->threshold = 1;
+  rmd->voxel_size = 0.1f;
+  rmd->adaptivity = 0.0f;
 }
 
 #ifdef WITH_MOD_REMESH
@@ -144,36 +147,50 @@ static Mesh *applyModifier(ModifierData *md, const ModifierEvalContext *UNUSED(c
 
   rmd = (RemeshModifierData *)md;
 
-  init_dualcon_mesh(&input, mesh);
-
-  if (rmd->flag & MOD_REMESH_FLOOD_FILL) {
-    flags |= DUALCON_FLOOD_FILL;
+  if (rmd->mode == MOD_REMESH_VOXEL) {
+    /* OpenVDB modes. */
+    if (rmd->voxel_size == 0.0f) {
+      return NULL;
+    }
+    result = BKE_mesh_remesh_voxel_to_mesh_nomain(mesh, rmd->voxel_size, rmd->adaptivity, 0.0f);
   }
+  else {
+    /* Dualcon modes. */
+    init_dualcon_mesh(&input, mesh);
 
-  switch (rmd->mode) {
-    case MOD_REMESH_CENTROID:
-      mode = DUALCON_CENTROID;
-      break;
-    case MOD_REMESH_MASS_POINT:
-      mode = DUALCON_MASS_POINT;
-      break;
-    case MOD_REMESH_SHARP_FEATURES:
-      mode = DUALCON_SHARP_FEATURES;
-      break;
-  }
+    if (rmd->flag & MOD_REMESH_FLOOD_FILL) {
+      flags |= DUALCON_FLOOD_FILL;
+    }
 
-  output = dualcon(&input,
-                   dualcon_alloc_output,
-                   dualcon_add_vert,
-                   dualcon_add_quad,
-                   flags,
-                   mode,
-                   rmd->threshold,
-                   rmd->hermite_num,
-                   rmd->scale,
-                   rmd->depth);
-  result = output->mesh;
-  MEM_freeN(output);
+    switch (rmd->mode) {
+      case MOD_REMESH_CENTROID:
+        mode = DUALCON_CENTROID;
+        break;
+      case MOD_REMESH_MASS_POINT:
+        mode = DUALCON_MASS_POINT;
+        break;
+      case MOD_REMESH_SHARP_FEATURES:
+        mode = DUALCON_SHARP_FEATURES;
+        break;
+      case MOD_REMESH_VOXEL:
+        /* Should have been processed before as an OpenVDB operation. */
+        BLI_assert(false);
+        break;
+    }
+
+    output = dualcon(&input,
+                     dualcon_alloc_output,
+                     dualcon_add_vert,
+                     dualcon_add_quad,
+                     flags,
+                     mode,
+                     rmd->threshold,
+                     rmd->hermite_num,
+                     rmd->scale,
+                     rmd->depth);
+    result = output->mesh;
+    MEM_freeN(output);
+  }
 
   if (rmd->flag & MOD_REMESH_SMOOTH_SHADING) {
     MPoly *mpoly = result->mpoly;