Triangulate modifier

Useful for bump map baking where a consistent triangulation should be enforced when baking/exporting/importing, to avoid artifacts caused by a different triangulation of the mesh by that which was used for baking by internal/external tools. 

documentation is here http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.65/More_Features

Will probably add some pictures too to demonstrate the issue that is solved more clearly.
Currently using the skin modifier icon, will soon change that.

Review by Brecht, thanks!

1 files changed, 147 insertions, 0 deletions

diff --git a/source/blender/modifiers/intern/MOD_triangulate.c b/source/blender/modifiers/intern/MOD_triangulate.c
new file mode 100644
index 00000000000..a9ec30067bf
--- /dev/null
+++ b/source/blender/modifiers/intern/MOD_triangulate.c
@@ -0,0 +1,147 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software  Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Contributor(s): Antony Riakiotakis
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ *
+ */
+
+/** \file blender/modifiers/intern/MOD_triangulate.c
+ *  \ingroup modifiers
+ */
+#include <string.h>
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+#include "DNA_object_types.h"
+#include "DNA_modifier_types.h"
+
+#include "BLI_utildefines.h"
+#include "BLI_string.h"
+#include "BLI_array.h"
+
+#include "BKE_cdderivedmesh.h"
+#include "BKE_deform.h"
+#include "BKE_DerivedMesh.h"
+#include "BKE_mesh.h"
+#include "BKE_modifier.h"
+#include "BKE_tessmesh.h"
+
+#include "MOD_util.h"
+
+/* triangulation modifier, directly calls the bmesh operator */
+
+static DerivedMesh *triangulate(DerivedMesh *dm, char use_beauty)
+{
+	DerivedMesh *result;
+	BMesh *bm;
+
+	bm = DM_to_bmesh(dm);
+
+	BMO_push(bm, NULL);
+	BMO_op_callf(bm, BMO_FLAG_DEFAULTS,
+				  "triangulate faces=%af use_beauty=%b", use_beauty);
+
+	BMO_pop(bm);
+
+	result = CDDM_from_bmesh(bm, FALSE);
+	BM_mesh_free(bm);
+
+	CDDM_calc_edges(result);
+	CDDM_calc_normals(result);
+
+	return result;
+}
+
+
+static void initData(ModifierData *md)
+{
+	TriangulateModifierData *tmd = (TriangulateModifierData *)md;
+
+	/* Enable in editmode by default */
+	md->mode |= eModifierMode_Editmode;
+	tmd->beauty = TRUE;
+}
+
+
+static void copyData(ModifierData *md, ModifierData *target)
+{
+	TriangulateModifierData *smd = (TriangulateModifierData *) md;
+	TriangulateModifierData *tsmd = (TriangulateModifierData *) target;
+
+	*tsmd = *smd;
+}
+
+static DerivedMesh *applyModifierEM(ModifierData *md,
+                                    Object *UNUSED(ob),
+                                    struct BMEditMesh *UNUSED(em),
+                                    DerivedMesh *dm)
+{
+	TriangulateModifierData *tmd = (TriangulateModifierData *)md;
+	DerivedMesh *result;
+	if (!(result = triangulate(dm, tmd->beauty))) {
+		return dm;
+	}
+
+	return result;
+}
+
+static DerivedMesh *applyModifier(ModifierData *md,
+                                  Object *UNUSED(ob),
+                                  DerivedMesh *dm,
+                                  ModifierApplyFlag UNUSED(flag))
+{
+	TriangulateModifierData *tmd = (TriangulateModifierData *)md;
+	DerivedMesh *result;
+	if(!(result = triangulate(dm, tmd->beauty))) {
+		return dm;
+	}
+
+	return result;
+}
+
+ModifierTypeInfo modifierType_Triangulate = {
+	/* name */              "Triangulate",
+	/* structName */        "TriangulateModifierData",
+	/* structSize */        sizeof(TriangulateModifierData),
+	/* type */              eModifierTypeType_Constructive,
+	/* flags */             eModifierTypeFlag_AcceptsMesh |
+							eModifierTypeFlag_SupportsEditmode |
+							eModifierTypeFlag_SupportsMapping |
+							eModifierTypeFlag_EnableInEditmode |
+							eModifierTypeFlag_AcceptsCVs,
+
+	/* copyData */          copyData,
+	/* deformVerts */       NULL,
+	/* deformMatrices */    NULL,
+	/* deformVertsEM */     NULL,
+	/* deformMatricesEM */  NULL,
+	/* applyModifier */     applyModifier,
+	/* applyModifierEM */   applyModifierEM,
+	/* initData */          initData,
+	/* requiredDataMask */  NULL, //requiredDataMask,
+	/* freeData */          NULL,
+	/* isDisabled */        NULL,
+	/* updateDepgraph */    NULL,
+	/* dependsOnTime */     NULL,
+	/* dependsOnNormals */	NULL,
+	/* foreachObjectLink */ NULL,
+	/* foreachIDLink */     NULL,
+};