open3d::t::pipelines::slac::ControlGrid Class Reference

#include <ControlGrid.h>

Public Member Functions
	ControlGrid ()=default
	Default constructor.
	ControlGrid (float grid_size, int64_t grid_count=1000, const core::Device &device=core::Device("CPU:0"))
	Constructor with initial grid size and grid count estimation.
	ControlGrid (float grid_size, const core::Tensor &keys, const core::Tensor &values, const core::Device &device=core::Device("CPU:0"))
void	Touch (const geometry::PointCloud &pcd)
	Allocate control grids in the shared camera space.
void	Compactify ()
std::tuple< core::Tensor, core::Tensor, core::Tensor >	GetNeighborGridMap ()
geometry::PointCloud	Parameterize (const geometry::PointCloud &pcd)
geometry::PointCloud	Deform (const geometry::PointCloud &pcd)
	Non-rigidly deform a point cloud using the control grid.
geometry::Image	Deform (const geometry::Image &depth, const core::Tensor &intrinsics, const core::Tensor &extrinsics, float depth_scale, float depth_max)
geometry::RGBDImage	Deform (const geometry::RGBDImage &rgbd, const core::Tensor &intrinsics, const core::Tensor &extrinsics, float depth_scale, float depth_max)
core::Tensor	GetInitPositions ()
	Get control grid original positions directly from tensor keys.
core::Tensor	GetCurrPositions ()
std::shared_ptr< core::HashMap >	GetHashMap ()
int64_t	Size ()
core::Device	GetDevice ()
int64_t	GetAnchorIdx ()

Static Public Attributes
static const std::string	kGrid8NbIndices = "Grid8NbIndices"
static const std::string	kGrid8NbVertexInterpRatios
	8 neighbor grid interpolation ratio for vertex per point.
static const std::string	kGrid8NbNormalInterpRatios
	8 neighbor grid interpolation ratio for normal per point.

Detailed Description

ControlGrid is a spatially hashed voxel grid used for non-rigid point cloud registration and TSDF integration. Each grid stores a map from the initial grid location to the deformed location. You can imagine a control grid as a jelly that is warped upon perturbation with its overall shape preserved. Reference: https://github.com/qianyizh/ElasticReconstruction/blob/master/FragmentOptimizer/OptApp.cpp http://vladlen.info/papers/elastic-fragments.pdf

Constructor & Destructor Documentation

ControlGrid() [1/3]

open3d::t::pipelines::slac::ControlGrid::ControlGrid ( )

default

Default constructor.

ControlGrid() [2/3]

open3d::t::pipelines::slac::ControlGrid::ControlGrid	(	float	grid_size,
		int64_t	grid_count = 1000,
		const core::Device &	device = core::Device("CPU:0") )

Constructor with initial grid size and grid count estimation.

ControlGrid() [3/3]

open3d::t::pipelines::slac::ControlGrid::ControlGrid	(	float	grid_size,
		const core::Tensor &	keys,
		const core::Tensor &	values,
		const core::Device &	device = core::Device("CPU:0") )

Constructor with known keys (Int32 x 3 positions) and values (Float32 x 3 shifted positions).

Member Function Documentation

Compactify()

void open3d::t::pipelines::slac::ControlGrid::Compactify

(

)

Force rehashing, so that all entries are remapped to [0, size) and form a contiguous index map.

Deform() [1/3]

geometry::Image open3d::t::pipelines::slac::ControlGrid::Deform	(	const geometry::Image &	depth,
		const core::Tensor &	intrinsics,
		const core::Tensor &	extrinsics,
		float	depth_scale,
		float	depth_max )

Non-rigidly deform a depth image by

• unprojecting the depth image to a point cloud;
• deform the point cloud;
• project the deformed point cloud back to the image.

Deform() [2/3]

geometry::PointCloud open3d::t::pipelines::slac::ControlGrid::Deform

(

const geometry::PointCloud &

pcd

)

Non-rigidly deform a point cloud using the control grid.

Deform() [3/3]

geometry::RGBDImage open3d::t::pipelines::slac::ControlGrid::Deform	(	const geometry::RGBDImage &	rgbd,
		const core::Tensor &	intrinsics,
		const core::Tensor &	extrinsics,
		float	depth_scale,
		float	depth_max )

Non-rigidly deform an RGBD image by

• unprojecting the depth image to a point cloud;
• deform the point cloud;
• project the deformed point cloud back to the image.

GetAnchorIdx()

int64_t open3d::t::pipelines::slac::ControlGrid::GetAnchorIdx ( )

inline

GetCurrPositions()

core::Tensor open3d::t::pipelines::slac::ControlGrid::GetCurrPositions ( )

inline

Get control grid shifted positions from tensor values (optimized in-place).

GetDevice()

core::Device open3d::t::pipelines::slac::ControlGrid::GetDevice ( )

inline

GetHashMap()

std::shared_ptr< core::HashMap > open3d::t::pipelines::slac::ControlGrid::GetHashMap ( )

inline

GetInitPositions()

core::Tensor open3d::t::pipelines::slac::ControlGrid::GetInitPositions ( )

inline

Get control grid original positions directly from tensor keys.

GetNeighborGridMap()

std::tuple< core::Tensor, core::Tensor, core::Tensor > open3d::t::pipelines::slac::ControlGrid::GetNeighborGridMap

(

)

Get the neighbor indices per grid to construct the regularizer.

Returns

A 6-way neighbor grid map for all the active entries of shape (N, ).

• buf_indices Active indices in the buffer of shape (N, )
• buf_indices_nb Neighbor indices (including non-allocated entries) for the active entries of shape (N, 6).
• masks_nb Corresponding neighbor masks of shape (N, 6).

Parameterize()

geometry::PointCloud open3d::t::pipelines::slac::ControlGrid::Parameterize

(

const geometry::PointCloud &

pcd

)

Parameterize an input point cloud by embedding each point in the grid with 8 corners via indexing and interpolation.

Returns

A PointCloud with parameterization attributes:

• neighbors: Index of 8 neighbor control grid points of shape (8, ) in Int64.
• ratios: Interpolation ratios of 8 neighbor control grid points of shape (8, ) in Float32.

TODO(wei): allow entries with less than 8 neighbors, probably in a kernel. Now we simply discard them and only accepts points with all 8 neighbors in the control grid map.

Size()

int64_t open3d::t::pipelines::slac::ControlGrid::Size ( )

inline

Touch()

void open3d::t::pipelines::slac::ControlGrid::Touch

(

const geometry::PointCloud &

pcd

)

Allocate control grids in the shared camera space.

Field Documentation

kGrid8NbIndices

const std::string open3d::t::pipelines::slac::ControlGrid::kGrid8NbIndices = "Grid8NbIndices"

static

Attributes used to extend the point cloud to support neighbor lookup. 8 neighbor grid index per point.

kGrid8NbNormalInterpRatios

const std::string open3d::t::pipelines::slac::ControlGrid::kGrid8NbNormalInterpRatios

static

Initial value:

                                                  =
"Grid8NbNormalInterpRatios"

8 neighbor grid interpolation ratio for normal per point.

kGrid8NbVertexInterpRatios

const std::string open3d::t::pipelines::slac::ControlGrid::kGrid8NbVertexInterpRatios

static

Initial value:

                                                  =
"Grid8NbVertexInterpRatios"

8 neighbor grid interpolation ratio for vertex per point.

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The documentation for this class was generated from the following files:

• cpp/open3d/t/pipelines/slac/ControlGrid.h
• cpp/open3d/t/pipelines/slac/ControlGrid.cpp