M3dimMesh

Board	Supported
Host System	Yes
V4L2	Yes
Clarity UHD	Yes
Concord PoE	No
GenTL	Yes
GevIQ	Yes
GigE Vision	Yes
Indio	No
Iris GTX	Yes
Radient eV-CL	Yes
Rapixo CL	Yes
Rapixo CoF	Yes
Rapixo CXP	Yes
USB3 Vision	Yes

Create a 3D mesh structure for a point cloud or depth map.

Syntax

void M3dimMesh(
    AIL_ID    MeshContext3dimId,  //in
    AIL_ID    SrcContainerBufId,  //in
    AIL_ID    DstContainerBufId,  //out
    AIL_INT64 ControlFlag         //in
)

Description

This function generates a triangular mesh structure for the source container's point cloud or depth map, using the specified surface reconstruction mode. The mesh data is stored in an M_COMPONENT_MESH_AIL component, which is added to the destination container.

You can choose the surface reconstruction mode with which to create the mesh, either organized, local plane, or smoothed. Use M3dimControl with M_MESH_MODE to set the mode, or use this function to specify a predefined context that uses default settings to create the mesh.

The organized surface reconstruction mode (M_MESH_ORGANIZED) requires an organized point cloud or depth map and connects neighboring points to create the mesh. With this mode, invalid data points in the point cloud or depth map result in a mesh with holes. No change is made to the source container's M_COMPONENT_RANGE and M_COMPONENT_CONFIDENCE components; they are simply copied over to the destination container. If the components M_COMPONENT_INTENSITY, M_COMPONENT_NORMALS_AIL, and M_COMPONENT_REFLECTANCE exist in the source container, these are also copied to the destination container.

The local plane reconstruction mode (M_MESH_LOCAL_PLANE) also connects neighboring points to create the mesh; however, it uses local planes computed from each point's neighborhood to establish which neighbors to connect. For each point, neighborhood points are projected to the local plane and the most suitable points are chosen to form a mesh triangle with the point in question. Note that the triangle's vertices are points from the original point cloud, which can be organized or unorganized. With this mode, the mesh can have holes. Components are handled in the same way as for the organized surface reconstruction mode. Note that normal vectors at each 3D point are required (M_COMPONENT_NORMALS_AIL component). Note also that this mode is only available for point clouds.

The smoothed surface reconstruction mode (M_MESH_SMOOTHED) also requires a point cloud and normal vectors at each 3D point (M_COMPONENT_NORMALS_AIL component), and generates a mesh by solving a Poisson equation. This approach generates a smooth surface even when the source point cloud is noisy; missing data is approximated when possible, resulting in significantly fewer holes. Before solving the Poisson equation, an octree is built, which partitions the 3D space for the mesh calculation. The octree's depth determines the mesh's resolution. Note that a higher octree depth gives a higher resolution, but a slower calculation time. Smoothed surface reconstruction generates a new point cloud; new M_COMPONENT_RANGE and M_COMPONENT_CONFIDENCE components are added to the destination container, along with the mesh component.

To remove points from the point cloud whose confidence is equal to zero, as well as points that are not part of the mesh, use M3dimRemovePoints with M_NOT_MESH_POINTS.

Note: Note that, when using the smoothed surface reconstruction mode, no M_COMPONENT_NORMALS_AIL component is added to the destination container.

To determine the number of triangular faces in the mesh, inquire the M_COMPONENT_MESH_AIL component using MbufInquireContainer with M_SIZE_X.

Inquiring the M_SIZE_Y value of the M_COMPONENT_MESH_AIL component returns 3 for an unorganized destination point cloud (3 vertices for each triangular face), and 6 for an organized destination point cloud or depth map (3 vertices with corresponding coordinates in both X and Y).

Parameters

MeshContext3dimId (in, AIL_ID)

Specifies a mesh 3D image processing context.

For specifying the mesh 3D image processing context identifier

Value	Description
M_MESH_CONTEXT_LOCAL_PLANE	Specifies a predefined mesh 3D image processing context with all mesh context control types (M3dimControl) set to their default, except for M_MESH_MODE which is set to M_MESH_LOCAL_PLANE. Use this predefined context to create the mesh from local planes that are fit to neighboring points.

With the local plane surface reconstruction mode, local planes help determine which points in the source point cloud to connect. With this mode, the mesh can have holes.

Note: This value is not available for depth map containers. | | M_MESH_CONTEXT_ORGANIZED | Specifies a predefined mesh 3D image processing context with all mesh context control types (M3dimControl) set to their default, except for M_MESH_MODE which is set to M_MESH_ORGANIZED. Use this predefined context to create the mesh using the organized surface reconstruction mode.

With surface reconstruction from an organized point cloud or depth map, neighboring points are connected. Any invalid points will result in a mesh with holes. | | M_MESH_CONTEXT_SMOOTHED | Specifies a predefined mesh 3D image processing context with all mesh context control types (M3dimControl) set to their default, except for M_MESH_MODE which is set to M_MESH_SMOOTHED. Use this predefined context to generate a mesh with a smoothed surface.

With the smoothed surface reconstruction mode, the mesh structure is extrapolated from existing points and smoothing is applied to reduce the noise in the point cloud; missing data is approximated when possible, resulting in significantly fewer holes. This mode generates a new point cloud with a smooth surface.

Note: This value is not available for depth map containers. | | Mesh 3D image processing context identifier | Specifies the identifier of a mesh 3D image processing context, previously allocated using M3dimAlloc with M_MESH_CONTEXT.

Note: If a previously allocated context is specified, the function applies the mesh control settings specified using M3dimControl. |

SrcContainerBufId (in, AIL_ID)

Specifies the identifier of the 3D-processable point cloud or depth map container to use as the source.

DstContainerBufId (out, AIL_ID)

Specifies the identifier of the destination container, previously allocated using MbufAllocContainer with M_PROC. The destination container must not be a child container.

ControlFlag (in, AIL_INT64)

Reserved for future expansion and must be set to M_DEFAULT.