Skip to content

Implement t::geometry::TriangleMesh::RemoveUnreferencedVertices #6640

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ssheorey merged 1 commit into from
Mar 18, 2024
Merged

Implement t::geometry::TriangleMesh::RemoveUnreferencedVertices #6640

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
54 changes: 54 additions & 0 deletions cpp/open3d/t/geometry/TriangleMesh.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1252,6 +1252,60 @@ TriangleMesh TriangleMesh::SelectByIndex(const core::Tensor &indices) const {
return result;
}

TriangleMesh TriangleMesh::RemoveUnreferencedVertices() {
if (!HasVertexPositions() || GetVertexPositions().GetLength() == 0) {
utility::LogWarning(
"[RemoveUnreferencedVertices] TriangleMesh has no vertices.");
return *this;
}
GetVertexAttr().AssertSizeSynchronized();

core::Dtype tri_dtype = HasTriangleIndices()
? GetTriangleIndices().GetDtype()
: core::Int64;

int64_t num_verts_old = GetVertexPositions().GetLength();
// int mask for vertices as we need to remap indices.
core::Tensor vertex_mask = core::Tensor::Zeros({num_verts_old}, tri_dtype);

if (!HasTriangleIndices() || GetTriangleIndices().GetLength() == 0) {
utility::LogWarning(
"[RemoveUnreferencedVertices] TriangleMesh has no triangles. "
"Removing all vertices.");
// in this case we need to empty vertices and their attributes
} else {
GetTriangleAttr().AssertSizeSynchronized();
core::Tensor tris_cpu =
GetTriangleIndices().To(core::Device()).Contiguous();
DISPATCH_INT_DTYPE_PREFIX_TO_TEMPLATE(tri_dtype, tris, [&]() {
scalar_tris_t *tris_ptr = tris_cpu.GetDataPtr<scalar_tris_t>();
scalar_tris_t *vertex_mask_ptr =
vertex_mask.GetDataPtr<scalar_tris_t>();
for (int i = 0; i < tris_cpu.GetLength(); i++) {
vertex_mask_ptr[tris_ptr[3 * i]] = 1;
vertex_mask_ptr[tris_ptr[3 * i + 1]] = 1;
vertex_mask_ptr[tris_ptr[3 * i + 2]] = 1;
}

UpdateTriangleIndicesByVertexMask<scalar_tris_t>(tris_cpu,
vertex_mask);
});
}

// send the vertex mask to original device and apply to
// vertices
vertex_mask = vertex_mask.To(GetDevice(), core::Bool);
for (auto item : GetVertexAttr()) {
SetVertexAttr(item.first, item.second.IndexGet({vertex_mask}));
}

Copy link
Member

@ssheorey ssheorey Feb 27, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

nit: Add LogDebug message about how many vertices were removed.

utility::LogDebug(
"[RemoveUnreferencedVertices] {:d} vertices have been removed.",
(int)(num_verts_old - GetVertexPositions().GetLength()));

return *this;
}

} // namespace geometry
} // namespace t
} // namespace open3d
4 changes: 4 additions & 0 deletions cpp/open3d/t/geometry/TriangleMesh.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -945,6 +945,10 @@ class TriangleMesh : public Geometry, public DrawableGeometry {
/// an empty mesh.
TriangleMesh SelectByIndex(const core::Tensor &indices) const;

/// Removes unreferenced vertices from the mesh.
/// \return The reference to itself.
TriangleMesh RemoveUnreferencedVertices();

protected:
core::Device device_ = core::Device("CPU:0");
TensorMap vertex_attr_;
Expand Down
4 changes: 4 additions & 0 deletions cpp/pybind/t/geometry/trianglemesh.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -962,6 +962,10 @@ or has a negative value, it is ignored.
box = o3d.t.geometry.TriangleMesh.create_box()
top_face = box.select_by_index([2, 3, 6, 7])
)");

triangle_mesh.def("remove_unreferenced_vertices",
&TriangleMesh::RemoveUnreferencedVertices,
"Removes unreferenced vertices from the mesh in-place.");
}

} // namespace geometry
Expand Down
130 changes: 130 additions & 0 deletions cpp/tests/t/geometry/TriangleMesh.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1212,5 +1212,135 @@ TEST_P(TriangleMeshPermuteDevices, SelectByIndex) {
box_untouched.GetTriangleIndices()));
}

TEST_P(TriangleMeshPermuteDevices, RemoveUnreferencedVertices) {
core::Device device = GetParam();
t::geometry::TriangleMesh mesh_empty{device};

// check completely empty mesh
EXPECT_TRUE(mesh_empty.RemoveUnreferencedVertices().IsEmpty());

// check mesh w/o triangles
core::Tensor vertices_no_tris_orig =
core::Tensor::Ones({2, 3}, core::Float32, device);
mesh_empty.SetVertexPositions(vertices_no_tris_orig);
EXPECT_TRUE(mesh_empty.RemoveUnreferencedVertices().IsEmpty());

// Torus
core::Tensor verts = core::Tensor::Init<double>(
{
{0, 0, 0}, /* 0 */
{3.0, 0.0, 0.0},
{1.5, 0.0, 0.866025},
{1, 2, 3}, /* 3 */
{1.5, 0.0, -0.866025},
{1.5, 2.59808, 0.0},
{0.75, 1.29904, 0.866025},
{0.75, 1.29904, -0.866025},
{-1.5, 2.59808, 0},
{-0.75, 1.29904, 0.866025},
{-0.75, 1.29904, -0.866025},
{-3.0, 0.0, 0.0},
{-1.5, 0.0, 0.866025},
{-1.5, 0.0, -0.866025},
{-1.5, -2.59808, 0.0},
{-0.75, -1.29904, 0.866025},
{-0.75, -1.29904, -0.866025},
{4, 5, 6}, /* 17 */
{1.5, -2.59808, 0.0},
{0.75, -1.29904, 0.866025},
{0.75, -1.29904, -0.866025},
{7, 8, 9} /* 21 */
},
device);

core::Tensor tris = core::Tensor::Init<int32_t>(
{{5, 6, 1}, {1, 6, 2}, {6, 7, 2}, {2, 7, 4},
{7, 5, 4}, {4, 5, 1}, {8, 9, 5}, {5, 9, 6},
{9, 10, 6}, {6, 10, 7}, {10, 8, 7}, {7, 8, 5},
{11, 12, 8}, {8, 12, 9}, {12, 13, 9}, {9, 13, 10},
{13, 11, 10}, {10, 11, 8}, {14, 15, 11}, {11, 15, 12},
{15, 16, 12}, {12, 16, 13}, {16, 14, 13}, {13, 14, 11},
{18, 19, 14}, {14, 19, 15}, {19, 20, 15}, {15, 20, 16},
{20, 18, 16}, {16, 18, 14}, {1, 2, 18}, {18, 2, 19},
{2, 4, 19}, {19, 4, 20}, {4, 1, 20}, {20, 1, 18}},
device);
t::geometry::TriangleMesh torus{verts, tris};
core::Tensor vertex_colors = core::Tensor::Init<float>(
{{0.0, 0.0, 0.0}, {1.0, 1.0, 1.0}, {2.0, 2.0, 2.0},
{3.0, 3.0, 3.0}, {4.0, 4.0, 4.0}, {5.0, 5.0, 5.0},
{6.0, 6.0, 6.0}, {7.0, 7.0, 7.0}, {8.0, 8.0, 8.0},
{9.0, 9.0, 9.0}, {10.0, 10.0, 10.0}, {11.0, 11.0, 11.0},
{12.0, 12.0, 12.0}, {13.0, 13.0, 13.0}, {14.0, 14.0, 14.0},
{15.0, 15.0, 15.0}, {16.0, 16.0, 16.0}, {17.0, 17.0, 17.0},
{18.0, 18.0, 18.0}, {19.0, 19.0, 19.0}, {20.0, 20.0, 20.0},
{21.0, 21.0, 21.0}},
device);
core::Tensor vertex_labels =
core::Tensor::Init<float>(
{{0.0, 0.0, 0.0}, {1.0, 1.0, 1.0}, {2.0, 2.0, 2.0},
{3.0, 3.0, 3.0}, {4.0, 4.0, 4.0}, {5.0, 5.0, 5.0},
{6.0, 6.0, 6.0}, {7.0, 7.0, 7.0}, {8.0, 8.0, 8.0},
{9.0, 9.0, 9.0}, {10.0, 10.0, 10.0}, {11.0, 11.0, 11.0},
{12.0, 12.0, 12.0}, {13.0, 13.0, 13.0}, {14.0, 14.0, 14.0},
{15.0, 15.0, 15.0}, {16.0, 16.0, 16.0}, {17.0, 17.0, 17.0},
{18.0, 18.0, 18.0}, {19.0, 19.0, 19.0}, {20.0, 20.0, 20.0},
{21.0, 21.0, 21.0}},
device) *
10;

core::Tensor triangle_labels =
core::Tensor::Init<float>({{0.0, 0.0, 0.0}, {1.0, 1.0, 1.0},
{2.0, 2.0, 2.0}, {3.0, 3.0, 3.0},
{4.0, 4.0, 4.0}, {5.0, 5.0, 5.0},
{6.0, 6.0, 6.0}, {7.0, 7.0, 7.0},
{8.0, 8.0, 8.0}, {9.0, 9.0, 9.0},
{10.0, 10.0, 10.0}, {11.0, 11.0, 11.0},
{12.0, 12.0, 12.0}, {13.0, 13.0, 13.0},
{14.0, 14.0, 14.0}, {15.0, 15.0, 15.0},
{16.0, 16.0, 16.0}, {17.0, 17.0, 17.0},
{18.0, 18.0, 18.0}, {19.0, 19.0, 19.0},
{20.0, 20.0, 20.0}, {21.0, 21.0, 21.0},
{22.0, 22.0, 22.0}, {23.0, 23.0, 23.0},
{24.0, 24.0, 24.0}, {25.0, 25.0, 25.0},
{26.0, 26.0, 26.0}, {27.0, 27.0, 27.0},
{28.0, 28.0, 28.0}, {29.0, 29.0, 29.0},
{30.0, 30.0, 30.0}, {31.0, 31.0, 31.0},
{32.0, 32.0, 32.0}, {33.0, 33.0, 33.0},
{34.0, 34.0, 34.0}, {35.0, 35.0, 35.0}},
device) *
100;
torus.SetVertexColors(vertex_colors);
torus.SetVertexAttr("labels", vertex_labels);
torus.ComputeVertexNormals();
torus.ComputeTriangleNormals();

// set the expected value
core::Tensor verts_mask = core::Tensor::Init<bool>(
{0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0},
device);
core::Tensor expected_verts =
torus.GetVertexPositions().IndexGet({verts_mask});
core::Tensor expected_tris =
t::geometry::TriangleMesh::CreateTorus(2, 1, 6, 3, core::Float32,
core::Int32, device)
.GetTriangleIndices();
core::Tensor expected_vert_normals =
torus.GetVertexNormals().IndexGet({verts_mask});
core::Tensor expected_tri_normals = torus.GetTriangleNormals().Clone();
core::Tensor expected_vert_labels =
torus.GetVertexAttr("labels").IndexGet({verts_mask});
core::Tensor expected_vert_colors =
torus.GetVertexAttr("colors").IndexGet({verts_mask});

torus.RemoveUnreferencedVertices();

EXPECT_TRUE(torus.GetVertexPositions().AllClose(expected_verts));
EXPECT_TRUE(torus.GetVertexNormals().AllClose(expected_vert_normals));
EXPECT_TRUE(torus.GetVertexColors().AllClose(expected_vert_colors));
EXPECT_TRUE(torus.GetVertexAttr("labels").AllClose(expected_vert_labels));
EXPECT_TRUE(torus.GetTriangleIndices().AllClose(expected_tris));
EXPECT_TRUE(torus.GetTriangleNormals().AllClose(expected_tri_normals));
}

} // namespace tests
} // namespace open3d
49 changes: 49 additions & 0 deletions python/test/t/geometry/test_trianglemesh.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -660,3 +660,52 @@ def test_select_by_index_64(device):
untouched_sphere.vertex.positions)
assert sphere_custom.triangle.indices.allclose(
untouched_sphere.triangle.indices)


def check_no_unreferenced_vertices(device, int_t, float_t):
sphere = o3d.t.geometry.TriangleMesh.create_sphere(1, 3, float_t, int_t,
device)
expected_sphere = o3d.t.geometry.TriangleMesh.create_sphere(
1, 3, float_t, int_t, device)

sphere.remove_unreferenced_vertices()

# nothing should be removed
assert sphere.vertex.positions.allclose(expected_sphere.vertex.positions)
assert sphere.triangle.indices.allclose(expected_sphere.triangle.indices)


def check_remove_unreferenced_vertices(device, int_t, float_t):
expected_mobius = o3d.t.geometry.TriangleMesh.create_mobius(
10, 2, 1, 1, 1, 1, 1, float_t, int_t, device)

verts = o3c.Tensor(
[[0.5, 0.0, 0.0], [1.5, 0.0, 0.0], [0.424307, 0.308277, -0.154508],
[1.19373, 0.867294, 0.154508], [0.184017, 0.566346, -0.293893],
[0.434017, 1.33577, 0.293893], [-0.218199, 0.671548, -0.404508],
[-0.399835, 1.23057, 0.404508], [-0.684017, 0.496967, -0.475528],
[-0.934017, 0.678603, 0.475528], [-1.0, 0.0, -0.5], [-1.0, 0.0, 0.5],
[-0.934017, -0.678603, -0.475528], [-0.684017, -0.496967, 0.475528],
[-0.399835, -1.23057, -0.404508], [-0.218199, -0.671548, 0.404508],
[0.434017, -1.33577, -0.293893], [0.184017, -0.566346, 0.293893],
[0, 0, 0], [1.19373, -0.867294, -0.154508], [1, 1, 1],
[0.424307, -0.308277, 0.154508]], float_t, device)

tris = o3c.Tensor(
[[0, 3, 1], [0, 2, 3], [3, 2, 4], [3, 4, 5], [4, 7, 5], [4, 6, 7],
[7, 6, 8], [7, 8, 9], [8, 11, 9], [8, 10, 11], [11, 10, 12],
[11, 12, 13], [12, 15, 13], [12, 14, 15], [15, 14, 16], [15, 16, 17],
[16, 21, 17], [16, 19, 21], [19, 21, 1], [1, 21, 0]], int_t, device)

mobius = o3d.t.geometry.TriangleMesh(verts, tris)
mobius.remove_unreferenced_vertices()
assert mobius.vertex.positions.allclose(expected_mobius.vertex.positions)
assert mobius.triangle.indices.allclose(expected_mobius.triangle.indices)


@pytest.mark.parametrize("device", list_devices())
@pytest.mark.parametrize("int_t", (o3c.int32, o3c.int64))
@pytest.mark.parametrize("float_t", (o3c.float32, o3c.float64))
def test_remove_unreferenced_vertices(device, int_t, float_t):
check_no_unreferenced_vertices(device, int_t, float_t)
check_remove_unreferenced_vertices(device, int_t, float_t)