Add mathutils.bvhtree API

Originally D966 by @lukastoenne, with own additions

- trees can be initialized from Object's, BMesh,
  or passed in as vert+polygon arrays.
- original indices of ngons/faces are used. (instead of tessellated indices).
- ray_cast, find_nearest methods
- find overlapping faces between 2 trees

4 files changed, 1238 insertions, 0 deletions

diff --git a/source/blender/python/mathutils/CMakeLists.txt b/source/blender/python/mathutils/CMakeLists.txt
index ef6b090140b..f70f893aeac 100644
--- a/source/blender/python/mathutils/CMakeLists.txt
+++ b/source/blender/python/mathutils/CMakeLists.txt
@@ -22,6 +22,7 @@ set(INC
 	.
 	../../blenlib
 	../../blenkernel
+	../../bmesh
 	../../makesdna
 	../../../../intern/guardedalloc
 )
@@ -37,6 +38,7 @@ set(SRC
 	mathutils_Matrix.c
 	mathutils_Quaternion.c
 	mathutils_Vector.c
+	mathutils_bvhtree.c
 	mathutils_geometry.c
 	mathutils_interpolate.c
 	mathutils_kdtree.c
@@ -48,6 +50,7 @@ set(SRC
 	mathutils_Matrix.h
 	mathutils_Quaternion.h
 	mathutils_Vector.h
+	mathutils_bvhtree.h
 	mathutils_geometry.h
 	mathutils_interpolate.h
 	mathutils_kdtree.h
diff --git a/source/blender/python/mathutils/mathutils.c b/source/blender/python/mathutils/mathutils.c
index ba7f351996a..ec249e823e4 100644
--- a/source/blender/python/mathutils/mathutils.c
+++ b/source/blender/python/mathutils/mathutils.c
@@ -600,6 +600,7 @@ static struct PyModuleDef M_Mathutils_module_def = {
 #include "mathutils_geometry.h"
 #include "mathutils_interpolate.h"
 #ifndef MATH_STANDALONE
+#  include "mathutils_bvhtree.h"
 #  include "mathutils_kdtree.h"
 #  include "mathutils_noise.h"
 #endif
@@ -653,6 +654,11 @@ PyMODINIT_FUNC PyInit_mathutils(void)
 	PyDict_SetItemString(sys_modules, PyModule_GetName(submodule), submodule);
 	Py_INCREF(submodule);
 
+	/* BVHTree submodule */
+	PyModule_AddObject(mod, "bvhtree", (submodule = PyInit_mathutils_bvhtree()));
+	PyDict_SetItemString(sys_modules, PyModule_GetName(submodule), submodule);
+	Py_INCREF(submodule);
+
 	/* KDTree submodule */
 	PyModule_AddObject(mod, "kdtree", (submodule = PyInit_mathutils_kdtree()));
 	PyDict_SetItemString(sys_modules, PyModule_GetName(submodule), submodule);
diff --git a/source/blender/python/mathutils/mathutils_bvhtree.c b/source/blender/python/mathutils/mathutils_bvhtree.c
new file mode 100644
index 00000000000..b3b953256bd
--- /dev/null
+++ b/source/blender/python/mathutils/mathutils_bvhtree.c
@@ -0,0 +1,1193 @@
+/*
+ * ***** 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): Lukas Toenne, Campbell Barton
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/python/mathutils/mathutils_bvhtree.c
+ *  \ingroup mathutils
+ *
+ * This file defines the 'mathutils.bvhtree' module, a general purpose module to access
+ * blenders bvhtree for mesh surface nearest-element search and ray casting.
+ */
+
+#include <Python.h>
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_utildefines.h"
+#include "BLI_kdopbvh.h"
+#include "BLI_polyfill2d.h"
+#include "BLI_math.h"
+#include "BLI_ghash.h"
+#include "BLI_memarena.h"
+
+#include "BKE_bvhutils.h"
+
+#include "../generic/py_capi_utils.h"
+#include "../generic/python_utildefines.h"
+
+#include "mathutils.h"
+#include "mathutils_bvhtree.h"  /* own include */
+
+#ifndef MATH_STANDALONE
+#include "DNA_object_types.h"
+
+#include "BKE_customdata.h"
+#include "BKE_DerivedMesh.h"
+#include "BKE_editmesh_bvh.h"
+
+#include "bmesh.h"
+
+#include "../bmesh/bmesh_py_types.h"
+#endif  /* MATH_STANDALONE */
+
+
+#include "BLI_strict_flags.h"
+
+
+/* -------------------------------------------------------------------- */
+
+/** \name Docstring (snippets)
+ * \{ */
+
+#define PYBVH_FIND_GENERIC_DISTANCE_DOC \
+"   :arg distance: Maximum distance threshold.\n" \
+"   :type distance: float\n"
+
+#define PYBVH_FIND_GENERIC_RETURN_DOC \
+"   :return: Returns a tuple (:class:`Vector` location, :class:`Vector` normal, int index, float distance),\n" \
+"      Values will all be None if no hit is found.\n" \
+"   :rtype: :class:`tuple`\n"
+
+#define PYBVH_FROM_GENERIC_EPSILON_DOC \
+"   :arg epsilon: Increase the threshold for detecting overlap and raycast hits.\n" \
+"   :type epsilon: float\n"
+
+/** \} */
+
+/* sqrt(FLT_MAX) */
+#define PYBVH_MAX_DIST_STR "1.84467e+19"
+static const float max_dist_default = 1.844674352395373e+19f;
+
+static const char PY_BVH_TREE_TYPE_DEFAULT = 4;
+static const char PY_BVH_AXIS_DEFAULT = 6;
+
+typedef struct {
+	PyObject_HEAD
+	BVHTree *tree;
+	float epsilon;
+
+	float (*coords)[3];
+	unsigned int (*tris)[3];
+	unsigned int coords_len, tris_len;
+
+	/* Optional members */
+	/* aligned with 'tris' */
+	int *orig_index;
+	/* aligned with array that 'orig_index' points to */
+	float (*orig_normal)[3];
+} PyBVHTree;
+
+
+/* -------------------------------------------------------------------- */
+
+/** \name Utility helper functions
+ * \{ */
+
+static PyObject *bvhtree_CreatePyObject(
+        BVHTree *tree, float epsilon,
+
+        float (*coords)[3], unsigned int coords_len,
+        unsigned int (*tris)[3], unsigned int tris_len,
+
+        /* optional arrays */
+        int *orig_index, float (*orig_normal)[3])
+{
+	PyBVHTree *result = PyObject_New(PyBVHTree, &PyBVHTree_Type);
+
+	result->tree = tree;
+	result->epsilon = epsilon;
+
+	result->coords = coords;
+	result->tris = tris;
+	result->coords_len = coords_len;
+	result->tris_len = tris_len;
+
+	result->orig_index = orig_index;
+	result->orig_normal = orig_normal;
+
+	return (PyObject *)result;
+}
+
+/** \} */
+
+
+/* -------------------------------------------------------------------- */
+
+/** \name BVHTreeRayHit to Python utilities
+ * \{ */
+
+static void py_bvhtree_raycast_to_py_tuple(const BVHTreeRayHit *hit, PyObject *py_retval)
+{
+	BLI_assert(hit->index >= 0);
+	BLI_assert(PyTuple_GET_SIZE(py_retval) == 4);
+
+	PyTuple_SET_ITEMS(py_retval,
+	        Vector_CreatePyObject(hit->co, 3, NULL),
+	        Vector_CreatePyObject(hit->no, 3, NULL),
+	        PyLong_FromLong(hit->index),
+	        PyFloat_FromDouble(hit->dist));
+
+}
+
+static PyObject *py_bvhtree_raycast_to_py(const BVHTreeRayHit *hit)
+{
+	PyObject *py_retval = PyTuple_New(4);
+
+	py_bvhtree_raycast_to_py_tuple(hit, py_retval);
+
+	return py_retval;
+}
+
+static PyObject *py_bvhtree_raycast_to_py_none(void)
+{
+	PyObject *py_retval = PyTuple_New(4);
+
+	PyC_Tuple_Fill(py_retval, Py_None);
+
+	return py_retval;
+}
+
+#if 0
+static PyObject *py_bvhtree_raycast_to_py_and_check(const BVHTreeRayHit *hit)
+{
+	PyObject *py_retval;
+
+	py_retval = PyTuple_New(4);
+
+	if (hit->index != -1) {
+		py_bvhtree_raycast_to_py_tuple(hit, py_retval);
+	}
+	else {
+		PyC_Tuple_Fill(py_retval, Py_None);
+	}
+
+	return py_retval;
+}
+#endif
+
+/** \} */
+
+
+/* -------------------------------------------------------------------- */
+
+/** \name BVHTreeNearest to Python utilities
+ * \{ */
+
+static void py_bvhtree_nearest_to_py_tuple(const BVHTreeNearest *nearest, PyObject *py_retval)
+{
+	BLI_assert(nearest->index >= 0);
+	BLI_assert(PyTuple_GET_SIZE(py_retval) == 4);
+
+	PyTuple_SET_ITEMS(py_retval,
+	        Vector_CreatePyObject(nearest->co, 3, NULL),
+	        Vector_CreatePyObject(nearest->no, 3, NULL),
+	        PyLong_FromLong(nearest->index),
+	        PyFloat_FromDouble(sqrtf(nearest->dist_sq)));
+
+}
+
+static PyObject *py_bvhtree_nearest_to_py(const BVHTreeNearest *nearest)
+{
+	PyObject *py_retval = PyTuple_New(4);
+
+	py_bvhtree_nearest_to_py_tuple(nearest, py_retval);
+
+	return py_retval;
+}
+
+static PyObject *py_bvhtree_nearest_to_py_none(void)
+{
+	PyObject *py_retval = PyTuple_New(4);
+
+	PyC_Tuple_Fill(py_retval, Py_None);
+
+	return py_retval;
+}
+
+#if 0
+static PyObject *py_bvhtree_nearest_to_py_and_check(const BVHTreeNearest *nearest)
+{
+	PyObject *py_retval;
+
+	py_retval = PyTuple_New(4);
+
+	if (nearest->index != -1) {
+		py_bvhtree_nearest_to_py_tuple(nearest, py_retval);
+	}
+	else {
+		PyC_Tuple_Fill(py_retval, Py_None);
+	}
+
+	return py_retval;
+}
+#endif
+
+/** \} */
+
+static void py_bvhtree__tp_dealloc(PyBVHTree *self)
+{
+	if (self->tree) {
+		BLI_bvhtree_free(self->tree);
+	}
+
+	MEM_SAFE_FREE(self->coords);
+	MEM_SAFE_FREE(self->tris);
+
+	MEM_SAFE_FREE(self->orig_index);
+	MEM_SAFE_FREE(self->orig_normal);
+
+	Py_TYPE(self)->tp_free((PyObject *)self);
+}
+
+
+/* -------------------------------------------------------------------- */
+
+/** \name Methods
+ * \{ */
+
+static void py_bvhtree_raycast_cb(void *userdata, int index, const BVHTreeRay *ray, BVHTreeRayHit *hit)
+{
+	const PyBVHTree *self = userdata;
+
+	const float (*coords)[3] = self->coords;
+	const unsigned int *tri = self->tris[index];
+	const float *tri_co[3] = {coords[tri[0]], coords[tri[1]], coords[tri[2]]};
+	float dist;
+
+	if (self->epsilon == 0.0f) {
+		dist = bvhtree_ray_tri_intersection(ray, hit->dist, UNPACK3(tri_co));
+	}
+	else {
+		dist = bvhtree_sphereray_tri_intersection(ray, self->epsilon, hit->dist, UNPACK3(tri_co));
+	}
+
+	if (dist >= 0 && dist < hit->dist) {
+		hit->index = self->orig_index ? self->orig_index[index] : index;
+		hit->dist = dist;
+		madd_v3_v3v3fl(hit->co, ray->origin, ray->direction, dist);
+		if (self->orig_normal) {
+			copy_v3_v3(hit->no, self->orig_normal[hit->index]);
+		}
+		else {
+			normal_tri_v3(hit->no, UNPACK3(tri_co));
+		}
+	}
+}
+
+static void py_bvhtree_nearest_point_cb(void *userdata, int index, const float co[3], BVHTreeNearest *nearest)
+{
+	PyBVHTree *self = userdata;
+
+	const float (*coords)[3] = self->coords;
+	const unsigned int *tri = self->tris[index];
+	const float *tri_co[3] = {coords[tri[0]], coords[tri[1]], coords[tri[2]]};
+	float nearest_tmp[3], dist_sq;
+
+	closest_on_tri_to_point_v3(nearest_tmp, co, UNPACK3(tri_co));
+	dist_sq = len_squared_v3v3(co, nearest_tmp);
+
+	if (dist_sq < nearest->dist_sq) {
+		nearest->index = self->orig_index ? self->orig_index[index] : index;
+		nearest->dist_sq = dist_sq;
+		copy_v3_v3(nearest->co, nearest_tmp);
+		if (self->orig_normal) {
+			copy_v3_v3(nearest->no, self->orig_normal[nearest->index]);
+		}
+		else {
+			normal_tri_v3(nearest->no, UNPACK3(tri_co));
+		}
+	}
+}
+
+PyDoc_STRVAR(py_bvhtree_ray_cast_doc,
+".. method:: ray_cast(co, direction, distance=sys.float_info.max)\n"
+"\n"
+"   Cast a ray onto the mesh.\n"
+"\n"
+"   :arg co: Start location of the ray in object space.\n"
+"   :type co: :class:`Vector`\n"
+"   :arg direction: Direction of the ray in object space.\n"
+"   :type direction: :class:`Vector`\n"
+PYBVH_FIND_GENERIC_DISTANCE_DOC
+PYBVH_FIND_GENERIC_RETURN_DOC
+);
+static PyObject *py_bvhtree_ray_cast(PyBVHTree *self, PyObject *args)
+{
+	const char *error_prefix = "ray_cast";
+	float co[3], direction[3];
+	float max_dist = FLT_MAX;
+	BVHTreeRayHit hit;
+
+	/* parse args */
+	{
+		PyObject *py_co, *py_direction;
+
+		if (!PyArg_ParseTuple(
+		        args, (char *)"OO|f:ray_cast",
+		        &py_co, &py_direction, max_dist))
+		{
+			return NULL;
+		}
+
+		if ((mathutils_array_parse(co, 2, 3 | MU_ARRAY_ZERO, py_co, error_prefix) == -1) ||
+		    (mathutils_array_parse(direction, 2, 3 | MU_ARRAY_ZERO, py_direction, error_prefix) == -1))
+		{
+			return NULL;
+		}
+
+		normalize_v3(direction);
+	}
+
+	hit.dist = max_dist;
+	hit.index = -1;
+
+	/* may fail if the mesh has no faces, in that case the ray-cast misses */
+	if (self->tree) {
+		if (BLI_bvhtree_ray_cast(
+		        self->tree, co, direction, 0.0f, &hit,
+		        py_bvhtree_raycast_cb, self) != -1)
+		{
+			return py_bvhtree_raycast_to_py(&hit);
+		}
+	}
+
+	return py_bvhtree_raycast_to_py_none();
+}
+
+PyDoc_STRVAR(py_bvhtree_find_nearest_doc,
+".. method:: find_nearest(co, distance=" PYBVH_MAX_DIST_STR ")\n"
+"\n"
+"   Find the nearest element to a point.\n"
+"\n"
+"   :arg co: Find nearest element to this point.\n"
+"   :type co: :class:`Vector`\n"
+PYBVH_FIND_GENERIC_DISTANCE_DOC
+PYBVH_FIND_GENERIC_RETURN_DOC
+);
+static PyObject *py_bvhtree_find_nearest(PyBVHTree *self, PyObject *args)
+{
+	const char *error_prefix = "find_nearest";
+	float co[3];
+	float max_dist = max_dist_default;
+
+	BVHTreeNearest nearest;
+
+	/* parse args */
+	{
+		PyObject *py_co;
+
+		if (!PyArg_ParseTuple(
+		        args, (char *)"O|f:find_nearest",
+		        &py_co, &max_dist))
+		{
+			return NULL;
+		}
+
+		if (mathutils_array_parse(co, 2, 3 | MU_ARRAY_ZERO, py_co, error_prefix) == -1) {
+			return NULL;
+		}
+	}
+
+	nearest.index = -1;
+	nearest.dist_sq = max_dist * max_dist;
+
+	/* may fail if the mesh has no faces, in that case the ray-cast misses */
+	if (self->tree) {
+		if (BLI_bvhtree_find_nearest(
+		        self->tree, co, &nearest,
+		        py_bvhtree_nearest_point_cb, self) != -1)
+		{
+			return py_bvhtree_nearest_to_py(&nearest);
+		}
+	}
+
+	return py_bvhtree_nearest_to_py_none();
+}
+
+BLI_INLINE unsigned int overlap_hash(const void *overlap_v)
+{
+	const BVHTreeOverlap *overlap = overlap_v;
+	/* same constants as edge-hash */
+	return (((unsigned int)overlap->indexA * 65) ^ ((unsigned int)overlap->indexA * 31));
+}
+
+BLI_INLINE bool overlap_cmp(const void *a_v, const void *b_v)
+{
+	const BVHTreeOverlap *a = a_v;
+	const BVHTreeOverlap *b = b_v;
+	return (memcmp(a, b, sizeof(*a)) != 0);
+}
+
+PyDoc_STRVAR(py_bvhtree_overlap_doc,
+".. method:: overlap(other_tree)\n"
+"\n"
+"   Find overlapping indices between 2 trees.\n"
+"\n"
+"   :arg other_tree: Other tree to preform overlap test on.\n"
+"   :type other_tree: :class:`BVHTree`\n"
+"   :return: Returns a list of unique index pairs,"
+"      the first index referencing this tree, the second referencing the **other_tree**.\n"
+"   :rtype: :class:`list`\n"
+);
+static PyObject *py_bvhtree_overlap(PyBVHTree *self, PyBVHTree *other)
+{
+	BVHTreeOverlap *overlap;
+	unsigned int overlap_len = 0;
+	PyObject *ret;
+
+	if (!PyBVHTree_CheckExact(other)) {
+		PyErr_SetString(PyExc_ValueError, "Expected a BVHTree argument");
+		return NULL;
+	}
+
+	overlap = BLI_bvhtree_overlap(self->tree, other->tree, &overlap_len);
+
+	ret = PyList_New(0);
+
+	if (overlap == NULL) {
+		/* pass */
+	}
+	else {
+		const float epsilon = max_ff(self->epsilon, other->epsilon);
+		bool use_unique = (self->orig_index || other->orig_index);
+		GSet *pair_test = use_unique ? BLI_gset_new_ex(overlap_hash, overlap_cmp, __func__, overlap_len) : NULL;
+		/* simple case, no index remapping */
+		unsigned int i;
+
+		for (i = 0; i < overlap_len; i++) {
+			const unsigned int *tri_a = self->tris[overlap[i].indexA];
+			const unsigned int *tri_b = other->tris[overlap[i].indexB];
+			const float *tri_a_co[3] = {self->coords[tri_a[0]], self->coords[tri_a[1]], self->coords[tri_a[2]]};
+			const float *tri_b_co[3] = {other->coords[tri_b[0]], other->coords[tri_b[1]], other->coords[tri_b[2]]};
+
+			if (isect_tri_tri_epsilon_v3(UNPACK3(tri_a_co), UNPACK3(tri_b_co), NULL, NULL, epsilon)) {
+				PyObject *item;
+
+				if (use_unique) {
+					if (self->orig_index) {
+						overlap[i].indexA = self->orig_index[overlap[i].indexA];
+					}
+					if (other->orig_index) {
+						overlap[i].indexB = other->orig_index[overlap[i].indexB];
+					}
+
+					/* skip if its already added */
+					if (!BLI_gset_add(pair_test, &overlap[i])) {
+						continue;
+					}
+				}
+
+				item = PyTuple_New(2);
+				PyTuple_SET_ITEMS(item,
+				        PyLong_FromLong(overlap[i].indexA),
+				        PyLong_FromLong(overlap[i].indexB));
+
+				PyList_Append(ret, item);
+				Py_DECREF(item);
+			}
+		}
+
+		if (pair_test) {
+			BLI_gset_free(pair_test, NULL);
+		}
+	}
+
+	if (overlap) {
+		MEM_freeN(overlap);
+	}
+
+	return ret;
+}
+
+/** \} */
+
+
+/* -------------------------------------------------------------------- */
+
+/** \name Class Methods
+ * \{ */
+
+PyDoc_STRVAR(C_BVHTree_FromPolygons_doc,
+".. classmethod:: FromPolygons(vertices, polygons, all_triangles=False, epsilon=0.0)\n"
+"\n"
+"   BVH tree constructed geometry passed in as arguments.\n"
+"\n"
+"   :arg vertices: float triplets each representing ``(x, y, z)``\n"
+"   :type vertices: float triplet sequence\n"
+"   :arg polygons: Sequence of polyugons, each containing indices to the vertices argument.\n"
+"   :type polygons: Sequence of sequences containing ints\n"
+"   :arg all_triangles: Use when all **polygons** are triangles for more efficient conversion.\n"
+"   :type all_triangles: bool\n"
+PYBVH_FROM_GENERIC_EPSILON_DOC
+);
+static PyObject *C_BVHTree_FromPolygons(PyObject *UNUSED(cls), PyObject *args, PyObject *kwargs)
+{
+	const char *error_prefix = "BVHTree.FromPolygons";
+	const char *keywords[] = {"vertices", "polygons", "all_triangles", "epsilon", NULL};
+
+	PyObject *py_coords, *py_tris;
+	PyObject *py_coords_fast = NULL, *py_tris_fast = NULL;
+
+	MemArena *poly_arena = NULL;
+	MemArena *pf_arena = NULL;
+
+	float (*coords)[3] = NULL;
+	unsigned int (*tris)[3] = NULL;
+	unsigned int coords_len, tris_len;
+	float epsilon = 0.0f;
+	int all_triangles = 0;
+
+	/* when all_triangles is False */
+	int *orig_index = NULL;
+	float (*orig_normal)[3] = NULL;
+
+	unsigned int i;
+	bool valid = true;
+
+
+	if (!PyArg_ParseTupleAndKeywords(
+	        args, kwargs, (char *)"OO|$if:BVHTree.FromPolygons", (char **)keywords,
+	        &py_coords, &py_tris, &all_triangles, &epsilon))
+	{
+		return NULL;
+	}
+
+	if (!(py_coords_fast = PySequence_Fast(py_coords, error_prefix)) ||
+	    !(py_tris_fast  = PySequence_Fast(py_tris, error_prefix)))
+	{
+		Py_XDECREF(py_coords_fast);
+		return NULL;
+	}
+
+	if (valid) {
+		PyObject **py_coords_fast_items = PySequence_Fast_ITEMS(py_coords_fast);
+		coords_len = (unsigned int)PySequence_Fast_GET_SIZE(py_coords_fast);
+		coords = MEM_mallocN((size_t)coords_len * sizeof(*coords), __func__);
+
+		for (i = 0; i < coords_len; i++) {
+			PyObject *py_vert = py_coords_fast_items[i];
+
+			if (mathutils_array_parse(coords[i], 3, 3, py_vert, "BVHTree vertex: ") == -1) {
+				valid = false;
+				break;
+			}
+		}
+	}
+
+	if (valid == false) {
+		/* pass */
+	}
+	else if (all_triangles) {
+		/* all triangles, simple case */
+		PyObject **py_tris_fast_items = PySequence_Fast_ITEMS(py_tris_fast);
+		tris_len = (unsigned int)PySequence_Fast_GET_SIZE(py_tris_fast);
+		tris = MEM_mallocN((size_t)tris_len * sizeof(*tris), __func__);
+
+		for (i = 0; i < tris_len; i++) {
+			PyObject *py_tricoords = py_tris_fast_items[i];
+			PyObject *py_tricoords_fast;
+			PyObject **py_tricoords_fast_items;
+			unsigned int *tri = tris[i];
+			int j;
+
+			if (!(py_tricoords_fast = PySequence_Fast(py_tricoords, error_prefix))) {
+				valid = false;
+				break;
+			}
+
+			if (PySequence_Fast_GET_SIZE(py_tricoords_fast) != 3) {
+				Py_DECREF(py_tricoords_fast);
+				PyErr_Format(PyExc_ValueError,
+				             "%s: non triangle found at index %d with length of %d",
+				             error_prefix, i, PySequence_Fast_GET_SIZE(py_tricoords_fast));
+				valid = false;
+				break;
+			}
+
+			py_tricoords_fast_items = PySequence_Fast_ITEMS(py_tricoords_fast);
+
+			for (j = 0; j < 3; j++) {
+				tri[j] = (unsigned int)_PyLong_AsInt(py_tricoords_fast_items[j]);
+				if (UNLIKELY(tri[j] >= (unsigned int)coords_len)) {
+					PyErr_Format(PyExc_ValueError,
+					             "%s: index %d must be less than %d",
+					             error_prefix, tri[j], coords_len);
+
+					/* decref below */
+					valid = false;
+					break;
+				}
+			}
+
+			Py_DECREF(py_tricoords_fast);
+		}
+	}
+	else {
+		/* ngon support (much more involved) */
+		const unsigned int polys_len = (unsigned int)PySequence_Fast_GET_SIZE(py_tris_fast);
+		struct PolyLink {
+			struct PolyLink *next;
+			unsigned int len;
+			unsigned int poly[0];
+		} *plink_first = NULL, **p_plink_prev = &plink_first, *plink = NULL;
+		int poly_index;
+
+		tris_len = 0;
+
+		poly_arena = BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE, __func__);
+
+		for (i = 0; i < polys_len; i++) {
+			PyObject *py_tricoords = PySequence_Fast_GET_ITEM(py_tris_fast, i);
+			PyObject *py_tricoords_fast;
+			PyObject **py_tricoords_fast_items;
+			unsigned int py_tricoords_len;
+			unsigned int j;
+
+			if (!(py_tricoords_fast = PySequence_Fast(py_tricoords, error_prefix))) {
+				valid = false;
+				break;
+			}
+
+			py_tricoords_len = (unsigned int)PySequence_Fast_GET_SIZE(py_tricoords_fast);
+			py_tricoords_fast_items = PySequence_Fast_ITEMS(py_tricoords_fast);
+
+			plink = BLI_memarena_alloc(poly_arena, sizeof(*plink) + (sizeof(int) * (size_t)py_tricoords_len));
+
+			plink->len = (unsigned int)py_tricoords_len;
+			*p_plink_prev = plink;
+			p_plink_prev = &plink->next;
+
+			for (j = 0; j < py_tricoords_len; j++) {
+				plink->poly[j] = (unsigned int)_PyLong_AsInt(py_tricoords_fast_items[j]);
+				if (UNLIKELY(plink->poly[j] >= (unsigned int)coords_len)) {
+					PyErr_Format(PyExc_ValueError,
+					             "%s: index %d must be less than %d",
+					             error_prefix, plink->poly[j], coords_len);
+
+					Py_DECREF(py_tricoords_fast);
+					valid = false;
+					break;
+				}
+			}
+
+			if (py_tricoords_len >= 3) {
+				tris_len += (py_tricoords_len - 2);
+			}
+		}
+		*p_plink_prev = NULL;
+
+		/* all ngon's are parsed, now tessellate */
+
+		pf_arena = BLI_memarena_new(BLI_POLYFILL_ARENA_SIZE, __func__);
+		tris = MEM_mallocN(sizeof(*tris) * (size_t)tris_len, __func__);
+
+		orig_index = MEM_mallocN(sizeof(*orig_index) * (size_t)tris_len, __func__);
+		orig_normal = MEM_mallocN(sizeof(*orig_normal) * (size_t)polys_len, __func__);
+
+		for (plink = plink_first, poly_index = 0, i = 0; plink; plink = plink->next, poly_index++) {
+			if (plink->len == 3) {
+				unsigned int *tri = tris[i];
+				memcpy(tri, plink->poly, sizeof(unsigned int[3]));
+				orig_index[i] = poly_index;
+				normal_tri_v3(orig_normal[poly_index], coords[tri[0]], coords[tri[1]], coords[tri[2]]);
+				i++;
+			}
+			else if (plink->len > 3) {
+				float (*proj_coords)[2] = BLI_memarena_alloc(pf_arena, sizeof(*proj_coords) * plink->len);
+				float *normal = orig_normal[poly_index];
+				const float *co_prev;
+				const float *co_curr;
+				float axis_mat[3][3];
+				unsigned int (*tris_offset)[3] = &tris[i];
+				unsigned int j;
+
+				/* calc normal and setup 'proj_coords' */
+				zero_v3(normal);
+				co_prev = coords[plink->poly[plink->len - 1]];
+				for (j = 0; j < plink->len; j++) {
+					co_curr = coords[plink->poly[j]];
+					add_newell_cross_v3_v3v3(normal, co_prev, co_curr);
+					co_prev = co_curr;
+				}
+				normalize_v3(normal);
+
+				axis_dominant_v3_to_m3_negate(axis_mat, normal);
+
+				for (j = 0; j < plink->len; j++) {
+					mul_v2_m3v3(proj_coords[i], axis_mat, coords[plink->poly[j]]);
+				}
+
+				BLI_polyfill_calc_arena((const float (*)[2])proj_coords, plink->len, 1, tris_offset, pf_arena);
+
+				j = plink->len - 2;
+				while (j--) {
+					unsigned int *tri = tris_offset[j];
+					/* remap to global indices */
+					tri[0] = plink->poly[tri[0]];
+					tri[1] = plink->poly[tri[1]];
+					tri[2] = plink->poly[tri[2]];
+
+					orig_index[i] = poly_index;
+					i++;
+				}
+
+				BLI_memarena_clear(pf_arena);
+			}
+			else {
+				zero_v3(orig_normal[poly_index]);
+			}
+		}
+	}
+
+	Py_DECREF(py_coords_fast);
+	Py_DECREF(py_tris_fast);
+
+	if (pf_arena) {
+		BLI_memarena_free(pf_arena);
+	}
+
+	if (poly_arena) {
+		BLI_memarena_free(poly_arena);
+	}
+
+	if (valid) {
+		BVHTree *tree;
+
+		tree = BLI_bvhtree_new((int)tris_len, epsilon, PY_BVH_TREE_TYPE_DEFAULT, PY_BVH_AXIS_DEFAULT);
+		if (tree) {
+			for (i = 0; i < tris_len; i++) {
+				float co[3][3];
+
+				copy_v3_v3(co[0], coords[tris[i][0]]);
+				copy_v3_v3(co[1], coords[tris[i][1]]);
+				copy_v3_v3(co[2], coords[tris[i][2]]);
+
+				BLI_bvhtree_insert(tree, (int)i, co[0], 3);
+			}
+
+			BLI_bvhtree_balance(tree);
+		}
+
+		return bvhtree_CreatePyObject(
+		        tree, epsilon,
+		        coords, coords_len,
+		        tris, tris_len,
+		        orig_index, orig_normal);
+	}
+	else {
+		if (coords)
+			MEM_freeN(coords);
+		if (tris)
+			MEM_freeN(tris);
+
+		return NULL;
+	}
+}
+
+
+#ifndef MATH_STANDALONE
+
+PyDoc_STRVAR(C_BVHTree_FromBMesh_doc,
+".. classmethod:: FromBMesh(bmesh)\n"
+"\n"
+"   BVH tree based on :class:`BMesh` data.\n"
+"\n"
+"   :arg bmesh: BMesh data.\n"
+"   :type bmesh: :class:`BMesh`\n"
+);
+static PyObject *C_BVHTree_FromBMesh(PyObject *UNUSED(cls), PyObject *args, PyObject *kwargs)
+{
+	const char *keywords[] = {"bmesh", NULL};
+
+	BPy_BMesh *py_bm;
+
+	float (*coords)[3] = NULL;
+	unsigned int (*tris)[3] = NULL;
+	unsigned int coords_len, tris_len;
+	float epsilon = 0.0f;
+
+	BMesh *bm;
+	BMLoop *(*looptris)[3];
+
+	if (!PyArg_ParseTupleAndKeywords(
+	        args, kwargs, (char *)"O!|$f:BVHTree.FromBMesh", (char **)keywords,
+	        &BPy_BMesh_Type, &py_bm, &epsilon))
+	{
+		return NULL;
+	}
+
+	bm = py_bm->bm;
+
+	/* Get data for tessellation */
+	{
+		int tris_len_dummy;
+
+		coords_len = (unsigned int)bm->totvert;
+		tris_len = (unsigned int)poly_to_tri_count(bm->totface, bm->totloop);
+
+		coords = MEM_mallocN(sizeof(*coords) * (size_t)coords_len, __func__);
+		tris = MEM_mallocN(sizeof(*tris) * (size_t)tris_len, __func__);
+
+		looptris = MEM_mallocN(sizeof(*looptris) * (size_t)tris_len, __func__);
+
+		BM_bmesh_calc_tessellation(bm, looptris, &tris_len_dummy);
+		BLI_assert(tris_len_dummy == (int)tris_len);
+	}
+
+	{
+		BMIter iter;
+		BVHTree *tree;
+		unsigned int i;
+
+		int *orig_index = NULL;
+		float (*orig_normal)[3] = NULL;
+
+		tree = BLI_bvhtree_new((int)tris_len, epsilon, PY_BVH_TREE_TYPE_DEFAULT, PY_BVH_AXIS_DEFAULT);
+		if (tree) {
+			BMFace *f;
+			BMVert *v;
+
+			orig_index = MEM_mallocN(sizeof(*orig_index) * (size_t)tris_len, __func__);
+			orig_normal = MEM_mallocN(sizeof(*orig_normal) * (size_t)bm->totface, __func__);
+
+			BM_ITER_MESH_INDEX (v, &iter, bm, BM_VERTS_OF_MESH, i) {
+				copy_v3_v3(coords[i], v->co);
+				BM_elem_index_set(v, (int)i);  /* set_inline */
+			}
+			BM_ITER_MESH_INDEX (f, &iter, bm, BM_FACES_OF_MESH, i) {
+				copy_v3_v3(orig_normal[i], f->no);
+				BM_elem_index_set(f, (int)i);  /* set_inline */
+			}
+			bm->elem_index_dirty &= (char)~(BM_VERT | BM_FACE);
+
+			for (i = 0; i < tris_len; i++) {
+				float co[3][3];
+
+				tris[i][0] = (unsigned int)BM_elem_index_get(looptris[i][0]->v);
+				tris[i][1] = (unsigned int)BM_elem_index_get(looptris[i][1]->v);
+				tris[i][2] = (unsigned int)BM_elem_index_get(looptris[i][2]->v);
+
+				copy_v3_v3(co[0], coords[tris[i][0]]);
+				copy_v3_v3(co[1], coords[tris[i][1]]);
+				copy_v3_v3(co[2], coords[tris[i][2]]);
+
+				BLI_bvhtree_insert(tree, (int)i, co[0], 3);
+				orig_index[i] = BM_elem_index_get(looptris[i][0]->f);
+			}
+
+			BLI_bvhtree_balance(tree);
+		}
+
+		MEM_freeN(looptris);
+
+		return bvhtree_CreatePyObject(
+		        tree, epsilon,
+		        coords, coords_len,
+		        tris, tris_len,
+		        orig_index, orig_normal);
+	}
+}
+
+/* return various derived meshes based on requested settings */
+static DerivedMesh *bvh_get_derived_mesh(
+        const char *funcname, struct Scene *scene, Object *ob,
+        bool use_deform, bool use_render, bool use_cage)
+{
+	/* we only need minimum mesh data for topology and vertex locations */
+	CustomDataMask mask = CD_MASK_BAREMESH;
+
+	/* Write the display mesh into the dummy mesh */
+	if (use_deform) {
+		if (use_render) {
+			if (use_cage) {
+				PyErr_Format(PyExc_ValueError,
+				             "%s(...): cage arg is unsupported when (render=True)", funcname);
+				return NULL;
+			}
+			else {
+				return mesh_create_derived_render(scene, ob, mask);
+			}
+		}
+		else {
+			if (use_cage) {
+				return mesh_get_derived_deform(scene, ob, mask);  /* ob->derivedDeform */
+			}
+			else {
+				return mesh_get_derived_final(scene, ob, mask);  /* ob->derivedFinal */
+			}
+		}
+	}
+	else {
+		/* !use_deform */
+		if (use_render) {
+			if (use_cage) {
+				PyErr_Format(PyExc_ValueError,
+				             "%s(...): cage arg is unsupported when (render=True)", funcname);
+				return NULL;
+			}
+			else {
+				return mesh_create_derived_no_deform_render(scene, ob, NULL, mask);
+			}
+		}
+		else {
+			if (use_cage) {
+				PyErr_Format(PyExc_ValueError,
+				             "%s(...): cage arg is unsupported when (deform=False, render=False)", funcname);
+				return NULL;
+			}
+			else {
+				return mesh_create_derived_no_deform(scene, ob, NULL, mask);
+			}
+		}
+	}
+}
+
+PyDoc_STRVAR(C_BVHTree_FromObject_doc,
+".. classmethod:: FromObject(object, scene, deform=True, render=False, cage=False, epsilon=0.0)\n"
+"\n"
+"   BVH tree based on :class:`Object` data.\n"
+"\n"
+"   :arg object: Object data.\n"
+"   :type object: :class:`Object`\n"
+"   :arg scene: Scene data to use for evaluating the mesh.\n"
+"   :type scene: :class:`Scene`\n"
+"   :arg deform: Use mesh with deformations.\n"
+"   :type deform: bool\n"
+"   :arg render: Use render settings.\n"
+"   :type render: bool\n"
+"   :arg cage: Use render settings.\n"
+"   :type cage: bool\n"
+PYBVH_FROM_GENERIC_EPSILON_DOC
+);
+static PyObject *C_BVHTree_FromObject(PyObject *UNUSED(cls), PyObject *args, PyObject *kwargs)
+{
+	/* note, options here match 'bpy_bmesh_from_object' */
+	const char *keywords[] = {"object", "scene",  "deform", "render", "cage", "epsilon", NULL};
+
+	PyObject *py_ob, *py_scene;
+	Object *ob;
+	struct Scene *scene;
+	DerivedMesh *dm;
+	int use_deform = true;
+	int use_render = false;
+	int use_cage = false;
+
+	const MLoopTri *lt;
+	const MLoop *mloop;
+
+	float (*coords)[3] = NULL;
+	unsigned int (*tris)[3] = NULL;
+	unsigned int coords_len, tris_len;
+	float epsilon = 0.0f;
+
+	if (!PyArg_ParseTupleAndKeywords(
+	        args, kwargs, (char *)"OO|$iiif:BVHTree.FromObject", (char **)keywords,
+	        &py_ob, &py_scene, &use_deform, &use_render, &use_cage, &epsilon) ||
+	    ((ob = PyC_RNA_AsPointer(py_ob, "Object")) == NULL) ||
+	    ((scene = PyC_RNA_AsPointer(py_scene, "Scene")) == NULL))
+	{
+		return NULL;
+	}
+
+	dm = bvh_get_derived_mesh("BVHTree", scene, ob, use_deform, use_render, use_cage);
+	if (dm == NULL) {
+		return NULL;
+	}
+
+	/* Get data for tessellation */
+	{
+		DM_ensure_looptri(dm);
+		lt = dm->getLoopTriArray(dm);
+
+		tris_len = (unsigned int)dm->getNumLoopTri(dm);
+		coords_len = (unsigned int)dm->getNumVerts(dm);
+
+		coords = MEM_mallocN(sizeof(*coords) * (size_t)coords_len, __func__);
+		tris = MEM_mallocN(sizeof(*tris) * (size_t)tris_len, __func__);
+
+		dm->getVertCos(dm, coords);
+
+		mloop = dm->getLoopArray(dm);
+	}
+
+	{
+		BVHTree *tree;
+		unsigned int i;
+
+		int *orig_index = NULL;
+		float (*orig_normal)[3] = NULL;
+
+		tree = BLI_bvhtree_new((int)tris_len, epsilon, PY_BVH_TREE_TYPE_DEFAULT, PY_BVH_AXIS_DEFAULT);
+		if (tree) {
+			orig_index = MEM_mallocN(sizeof(*orig_index) * (size_t)tris_len, __func__);
+			orig_normal = dm->getPolyDataArray(dm, CD_NORMAL);  /* can be NULL */
+			if (orig_normal) {
+				orig_normal = MEM_dupallocN(orig_normal);
+			}
+
+			for (i = 0; i < tris_len; i++, lt++) {
+				float co[3][3];
+
+				tris[i][0] = mloop[lt->tri[0]].v;
+				tris[i][1] = mloop[lt->tri[1]].v;
+				tris[i][2] = mloop[lt->tri[2]].v;
+
+				copy_v3_v3(co[0], coords[tris[i][0]]);
+				copy_v3_v3(co[1], coords[tris[i][1]]);
+				copy_v3_v3(co[2], coords[tris[i][2]]);
+
+				BLI_bvhtree_insert(tree, (int)i, co[0], 3);
+				orig_index[i] = (int)lt->poly;
+			}
+
+			BLI_bvhtree_balance(tree);
+		}
+
+		dm->release(dm);
+
+		return bvhtree_CreatePyObject(
+		        tree, epsilon,
+		        coords, coords_len,
+		        tris, tris_len,
+		        orig_index, orig_normal);
+	}
+}
+#endif  /* MATH_STANDALONE */
+
+/** \} */
+
+
+/* -------------------------------------------------------------------- */
+
+/** \name Module & Type definition
+ * \{ */
+
+static PyMethodDef py_bvhtree_methods[] = {
+	{"ray_cast", (PyCFunction)py_bvhtree_ray_cast, METH_VARARGS, py_bvhtree_ray_cast_doc},
+	{"find", (PyCFunction)py_bvhtree_find_nearest, METH_VARARGS, py_bvhtree_find_nearest_doc},
+	{"overlap", (PyCFunction)py_bvhtree_overlap, METH_O, py_bvhtree_overlap_doc},
+
+	/* class methods */
+	{"FromPolygons", (PyCFunction) C_BVHTree_FromPolygons, METH_VARARGS | METH_KEYWORDS | METH_CLASS, C_BVHTree_FromPolygons_doc},
+#ifndef MATH_STANDALONE
+	{"FromBMesh", (PyCFunction) C_BVHTree_FromBMesh, METH_VARARGS | METH_KEYWORDS | METH_CLASS, C_BVHTree_FromBMesh_doc},
+	{"FromObject", (PyCFunction) C_BVHTree_FromObject, METH_VARARGS | METH_KEYWORDS | METH_CLASS, C_BVHTree_FromObject_doc},
+#endif
+	{NULL, NULL, 0, NULL}
+};
+
+PyTypeObject PyBVHTree_Type = {
+	PyVarObject_HEAD_INIT(NULL, 0)
+	"BVHTree",                                   /* tp_name */
+	sizeof(PyBVHTree),                           /* tp_basicsize */
+	0,                                           /* tp_itemsize */
+	/* methods */
+	(destructor)py_bvhtree__tp_dealloc,          /* tp_dealloc */
+	NULL,                                        /* tp_print */
+	NULL,                                        /* tp_getattr */
+	NULL,                                        /* tp_setattr */
+	NULL,                                        /* tp_compare */
+	NULL,                                        /* tp_repr */
+	NULL,                                        /* tp_as_number */
+	NULL,                                        /* tp_as_sequence */
+	NULL,                                        /* tp_as_mapping */
+	NULL,                                        /* tp_hash */
+	NULL,                                        /* tp_call */
+	NULL,                                        /* tp_str */
+	NULL,                                        /* tp_getattro */
+	NULL,                                        /* tp_setattro */
+	NULL,                                        /* tp_as_buffer */
+	Py_TPFLAGS_DEFAULT,                          /* tp_flags */
+	NULL,                                        /* Documentation string */
+	NULL,                                        /* tp_traverse */
+	NULL,                                        /* tp_clear */
+	NULL,                                        /* tp_richcompare */
+	0,                                           /* tp_weaklistoffset */
+	NULL,                                        /* tp_iter */
+	NULL,                                        /* tp_iternext */
+	py_bvhtree_methods,                          /* tp_methods */
+	NULL,                                        /* tp_members */
+	NULL,                                        /* tp_getset */
+	NULL,                                        /* tp_base */
+	NULL,                                        /* tp_dict */
+	NULL,                                        /* tp_descr_get */
+	NULL,                                        /* tp_descr_set */
+	0,                                           /* tp_dictoffset */
+	NULL,                                        /* tp_init */
+	(allocfunc)PyType_GenericAlloc,              /* tp_alloc */
+	(newfunc)PyType_GenericNew,                  /* tp_new */
+	(freefunc)0,                                 /* tp_free */
+	NULL,                                        /* tp_is_gc */
+	NULL,                                        /* tp_bases */
+	NULL,                                        /* tp_mro */
+	NULL,                                        /* tp_cache */
+	NULL,                                        /* tp_subclasses */
+	NULL,                                        /* tp_weaklist */
+	(destructor) NULL                            /* tp_del */
+};
+
+/* -------------------------------------------------------------------- */
+/* Module definition */
+
+PyDoc_STRVAR(py_bvhtree_doc,
+"BVH tree structures for proximity searches and ray casts on geometry."
+);
+static struct PyModuleDef bvhtree_moduledef = {
+	PyModuleDef_HEAD_INIT,
+	"mathutils.bvhtree",                         /* m_name */
+	py_bvhtree_doc,                              /* m_doc */
+	0,                                           /* m_size */
+	NULL,                                        /* m_methods */
+	NULL,                                        /* m_reload */
+	NULL,                                        /* m_traverse */
+	NULL,                                        /* m_clear */
+	NULL                                         /* m_free */
+};
+
+PyMODINIT_FUNC PyInit_mathutils_bvhtree(void)
+{
+	PyObject *m = PyModule_Create(&bvhtree_moduledef);
+
+	if (m == NULL) {
+		return NULL;
+	}
+
+	/* Register classes */
+	if (PyType_Ready(&PyBVHTree_Type) < 0) {
+		return NULL;
+	}
+
+	PyModule_AddObject(m, "BVHTree", (PyObject *)&PyBVHTree_Type);
+
+	return m;
+}
+
+/** \} */
diff --git a/source/blender/python/mathutils/mathutils_bvhtree.h b/source/blender/python/mathutils/mathutils_bvhtree.h
new file mode 100644
index 00000000000..634556d68f7
--- /dev/null
+++ b/source/blender/python/mathutils/mathutils_bvhtree.h
@@ -0,0 +1,36 @@
+/*
+ * ***** 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.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+
+/** \file blender/python/mathutils/mathutils_bvhtree.h
+ *  \ingroup mathutils
+ */
+
+#ifndef __MATHUTILS_BVHTREE_H__
+#define __MATHUTILS_BVHTREE_H__
+
+PyMODINIT_FUNC PyInit_mathutils_bvhtree(void);
+
+extern PyTypeObject PyBVHTree_Type;
+
+#define PyBVHTree_Check(_v)  PyObject_TypeCheck((_v), &PyBVHTree_Type)
+#define PyBVHTree_CheckExact(v)  (Py_TYPE(v) == &PyBVHTree_Type)
+
+#endif /* __MATHUTILS_BVHTREE_H__ */