project_object_model_3dT_project_object_model_3dProjectObjectModel3dProjectObjectModel3dproject_object_model_3d — Project a 3D object model into image coordinates.
The operator project_object_model_3dproject_object_model_3dProjectObjectModel3dProjectObjectModel3dproject_object_model_3d projects a
3D object model into the image coordinate system and returns the
projected contours in ModelContoursModelContoursModelContoursmodelContoursmodel_contours. This operator is
particularly useful for the visualization of 3D object models.
Note that primitives are not projected but silently ignored.
The coordinates of the 3D object model are given in the model coordinate
system (mcs), a 3D world coordinate system.
First, they are transformed into the camera coordinate system (ccs)
using the given PosePosePoseposepose.
Then, these coordinates are projected into the
image coordinate system based on the internal camera parameters
CamParamCamParamCamParamcamParamcam_param.
Thereby the pose is needed in the form
, see Transformations / Poses
and “Solution Guide III-C - 3D Vision”.
Thus, the PosePosePoseposepose describes the position
and orientation of the world coordinate system with respect to the
camera coordinate system.
The internal camera parameters CamParamCamParamCamParamcamParamcam_param describe the
projection characteristics of the camera (see
Calibration).
This parameter specifies which geometric data
of the 3D object model should be projected. If 'data'"data""data""data""data" is set
to 'faces'"faces""faces""faces""faces", the faces of the 3D object model are projected.
The faces are represented by their border lines in
ModelContoursModelContoursModelContoursmodelContoursmodel_contours. If 'data'"data""data""data""data" is set
to 'lines'"lines""lines""lines""lines", the 3D lines of the 3D object model are projected.
If 'data'"data""data""data""data" is set to
'points'"points""points""points""points", the points of the 3D object model are
projected. The projected points can be represented in
ModelContoursModelContoursModelContoursmodelContoursmodel_contours in different ways. The point representation
can be selected by using the generic parameter 'point_shape'"point_shape""point_shape""point_shape""point_shape"
(see below). Finally, if 'data'"data""data""data""data" is set to 'auto'"auto""auto""auto""auto",
HALCON automatically chooses the most descriptive geometry data
that is available in the 3D object model for visualization.
List of values:
'auto'"auto""auto""auto""auto", 'faces'"faces""faces""faces""faces",
'lines'"lines""lines""lines""lines", 'points'"points""points""points""points".
This parameter specifies how
points are represented in the output contour ModelContoursModelContoursModelContoursmodelContoursmodel_contours.
Consequently, this parameter only has an effect if the points of the
3D object model are selected for projection (see above).
If 'point_shape'"point_shape""point_shape""point_shape""point_shape" is set to 'circle'"circle""circle""circle""circle", points are
represented by circles, whereas if 'point_shape'"point_shape""point_shape""point_shape""point_shape" is set to
'cross'"cross""cross""cross""cross", points are represented by crosses. In both cases
the size of the points (i.e., the size of the circles or the size
of the crosses) can be specified by the generic parameter
'point_size'"point_size""point_size""point_size""point_size" (see below). The orientation of the crosses
can be specified by the generic parameter
'point_orientation'"point_orientation""point_orientation""point_orientation""point_orientation" (see below).
List of values:
'circle'"circle""circle""circle""circle", 'cross'"cross""cross""cross""cross".
This parameter specifies the size
of the point representation in the output contour
ModelContoursModelContoursModelContoursmodelContoursmodel_contours, i.e., the size of the circles or the size
of the crosses depending on the selected 'point_shape'"point_shape""point_shape""point_shape""point_shape".
Consequently, this parameter only has an effect if the points of
the 3D object model are selected for projection (see above).
The size must be given in pixel units. If 'point_size'"point_size""point_size""point_size""point_size"
is set to 0, each point is represented by a contour
that contains a single contour point.
This parameter specifies the
orientation of the crosses in radians. Consequently, this
parameter only has an effect if the points of the 3D object model
are selected for projection and 'point_shape'"point_shape""point_shape""point_shape""point_shape" is set
to 'cross'"cross""cross""cross""cross" (see above).
This parameter can be
used to switch on or off the removal of hidden surfaces. If
'hidden_surface_removal'"hidden_surface_removal""hidden_surface_removal""hidden_surface_removal""hidden_surface_removal" is set to 'true'"true""true""true""true", only those
projected edges are returned that are not hidden by faces of the 3D
object model. If 'hidden_surface_removal'"hidden_surface_removal""hidden_surface_removal""hidden_surface_removal""hidden_surface_removal" is set to
'false'"false""false""false""false", all projected edges are returned. This is faster
than a projection with 'hidden_surface_removal'"hidden_surface_removal""hidden_surface_removal""hidden_surface_removal""hidden_surface_removal" set to
'true'"true""true""true""true".
If the system variable (see set_systemset_systemSetSystemSetSystemset_system)
'opengl_hidden_surface_removal_enable'"opengl_hidden_surface_removal_enable""opengl_hidden_surface_removal_enable""opengl_hidden_surface_removal_enable""opengl_hidden_surface_removal_enable" is set to 'true'"true""true""true""true"
(which is the default if it is available) and 'hidden_surface_removal'"hidden_surface_removal""hidden_surface_removal""hidden_surface_removal""hidden_surface_removal"
is set to 'true'"true""true""true""true", the projection of the model is accelerated
using the graphics card.
Depending on the graphics card this is significantly faster than the non
accelerated algorithm. Be aware that the results of the OpenGL projection
are slightly different compared to the analytic projection. Notable, only
the contours visible through CamParamCamParamCamParamcamParamcam_param are projected in this
mode.
List of values:
'true'"true""true""true""true", 'false'"false""false""false""false".
3D edges are only projected if the
angle between the two 3D faces that are incident with the 3D edge
is at least 'min_face_angle'"min_face_angle""min_face_angle""min_face_angle""min_face_angle". If 'min_face_angle'"min_face_angle""min_face_angle""min_face_angle""min_face_angle"
is set to 0.0, all edges are projected. If
'min_face_angle'"min_face_angle""min_face_angle""min_face_angle""min_face_angle" is set to (equivalent to
180 degrees), only the silhouette of the 3D object model is returned.
This parameter can be used to suppress edges within curved
surfaces, e.g., the surface of a cylinder or cone.
Suggested values:
0.17, 0.26,
0.35, 0.52.
Default:
0.52.
Attention
Cameras with hypercentric lenses are not supported.
For displaying large faces with a non-zero distortion
in CamParamCamParamCamParamcamParamcam_param, note that the distortion is only applied to the
points of the model. In the projection, these points are subsequently
connected by straight lines. For a good approximation of the distorted
lines, please use a triangulation with sufficiently small triangles.
Execution Information
Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
project_object_model_3dproject_object_model_3dProjectObjectModel3dProjectObjectModel3dproject_object_model_3d returns 2 (
H_MSG_TRUE)
if all parameters are
correct. If necessary, an exception is raised. If the geometric
data that was selected for the projection is not available in the
3D object model, the error 9514 is raised.