file iges read
Allows you to read an IGES geometry file.
Format:
file iges read |
|---|
file_name = | string |
part_name = | an existing part |
geometry_type = | iges_geometry_type |
blanked_entities = | boolean |
level = | integer |
create_geometry = | iges_create_type |
scale = | real |
mesh_density = | integer |
tolerance = | real |
single_shell = | shell_opt |
location = | location |
orientation = | orientation |
relative_to = | an existing model, part or marker |
clean_on_import = | boolean |
Example:
file iges read & |
|---|
file_name = | "c:\data.igs" & |
geometry_type = | all & |
location = | 10 , 10 , 10 & |
orientation = | 0 , 0 , 0& |
relative_to = | ground |
Description:
Parameter | Value Type | Description |
|---|
file_name | String | Specifies the name of the IGES file containing the geometry, to be imported into Adams View for the FILE IGES READ command, or the name of the IGES file to be generated for the FILE IGES WRITE command. |
option_file_name | String | Specifies the name of the file that contains translation options specific to the geometry format under consideration. Note the options file is specific to either the import or the export operation and to the designated geometry format. |
part_name | An Existing Part | Specifies the name of an existing Adams View PART onto which the translated geometry will be placed. |
geometry_type | Iges_geometry_type | Specifies the type of geometric entities to be translated from the IGES file to Adams View. |
blanked_entities | Boolean | Specifies if invisible geometry is to be converted. |
level | Integer | Note: This argument has been deprecated and no longer has any influence. Specifies the IGES levels that are to be converted during the file read. |
create_geometry | Iges_create_type | Note: This argument has been deprecated and no longer has any influence. Specifies the type of Adams View geometry created when geometry is translated from the IGES file to Adams View. |
scale | Real | Specifies the scale factor to be applied to the size of the geometry created in Adams View |
mesh_density | Integer | Note: This argument has been deprecated and no longer has any influence. The mesh density specifies the number of rulings on a surface in each parametric (U/V) direction. |
tolerance | Real | Note: This argument has been deprecated and no longer has any influence. Specifies the tolerance value used in the approximation of curves and surfaces when they are translated into Adams View. |
single_shell | Shell_opt |
location | Location | Specifies the translational position where the geometry in the IGES file is to be located relative to the Adams View part lprf. |
orientation | Orientation | Specifies the angular position where the geometry in the IGES file is to be oriented relative to the Adams View part lprf. |
relative_to | An Existing Model, Part Or Marker | Specifies the coordinate system that location coordinates and orientation angles correspond to. |
clean_on_import(optional) | yes/no | Enables an automatic geometry scanner and cleaner behind-the-scenes during import of parasolid files. This process looks for small imperfections in the geometry that would render in not "watertight" and therefore cause problems with mass property calculations based on geometry and density/material. In some cases, this may slow down import speed of certain geometry. If disabling this option, be sure to verify that the volume Adams View calculates is still sufficiently accurate enough. Yes is the default. |
Extended Definition:
1. The Adams IGES translator is an optional module for Adams View. Adams IGES imports standard IGES geometry files from any CAD software package and operates on this data to convert it into a set of Adams View geometry elements. These elements can correspond either to standard Adams GRAPHICS statements or polylines. You associate the IGES geometry with any rigid body part of the Adams View model prior to, or subsequent to an Adams simulation.
2. Include the complete path name unless the file currently resides in the directory from which you are running Adams View.
If the files that you want to read into Adams View are not in the directory in which you are running AdamsAdams View, use the complete path name of the files. Enclose the full path name in double quotation marks ("") because the full path name includes special characters; characters other than alphabetic, numeric, or underscore characters. For more information, see
Using Extended Names.
If you want to include other characters, such as a '.' for an extension or '/' or '[]' for directory paths, you must enclose the name in quotes.
Adams View assumes that the file extension is ".igs." Therefore, you do not have to include the file extension if it is ".igs."
3. The geometry may be placed upon a part and used for preprocessing and postprocessing. Markers created by the IGES translator will be located on the part specified in this parameter.
You may identify a part by typing its name or by picking it from the screen.
If the part is not visible on the screen, you must type the name. You may also find it convenient to type the name even if the part is displayed.
If you created the part by reading an Adams data set or graphics file, the part name is the letters PAR followed by the Adams data set part ID number. For example, the name of Adams PART/101 is PAR101. If you created the part during preprocessing, you will have given it a name at that time.
If a part is available by default, you may identify it by entering only its name. If it is not, you must enter its full name. To identify a part under another model, for instance, you may need to enter the model name, as well. For example, you may specify part 'arm' from model 'robot' by entering ".robot.arm".
You must separate multiple part names by commas.
If the part is visible in one of your views, you may identify it by picking on any of the graphics associated with it.
You need not separate multiple part picks by commas.
4. Admissible values for the geometry_type parameter are:
Wireframe - This general type of geometry includes lines, arcs, curves, and splines.
Surface--The IGES translator supports all the standard surfaces. In the case of trimmed and bounded surfaces, the untrimmed surfaces and the associated model space trimming curves are processed, but no trimming is performed.
Text-Text implies annotation entities including leader lines, arrows, dimensions as well as alpha-numeric characters. All annotation data is stroked, so the relative size of most fonts is represented accurately. Stroked text is translated to Adams View as polylines. This allows for a more accurate representation of the size of the text in the IGES file but requires more memory than translating all text to one font.
Large amounts of text may adversely affect the performance of the IGES translator and Adams View.
All-All supported entities are translated to Adams View.
Any combination of these values may be specified. For example, the following command will translate surfaces and text from the IGES file to Adams View.
FILE IGES READ FILE="cylinder.igs"& GEOMETRY_TYPE=Surface,Text PART_NAME=.mod1.ground
5. Any IGES entity encountered in the IGES file may be blanked by the program that created the IGES file. This is similar to Adams View visibility. If you specify No for the BLANKED_ENTITIES parameter, then the blanked entities are not translated to Adams View. If you specify Yes for the BLANKED_ENTITIES parameter, then the blanked entities are translated to Adams View and they are made to be invisible.
IGES entities that are blanked are typically construction entities that are used in the definition of another geometric entity. For example, a line may be used as the center of rotation of another line in the definition of a cylinder. The center line, and the sweep line rotated about the center line, would both be blanked because they are temporary entities used in the construction of the cylinder.
Once blanked entities have been translated to Adams View, there is no distinction between construction entities and other geometry. The DISPLAY_ATTRIBUTES commands may be used to turn the visibility of the blanked entities on.
6. An IGES level is a means of associating geometry into a group. These groups may be manipulated as a single entity for purposes of visibility and color. IGES levels are defined by the program that generates the IGES file and are labeled with integers greater than or equal to zero. Levels are typically used to organize data for viewing and are similar to layers in the CAD sense. Adams View will read all levels by default if the LEVEL parameter is not specified.
Adams View allows specification of one level or a range of levels to be translated from the IGES file. The following command translates levels 10,11,12,13,14, and 15 from the IGES file to Adams View.
FILE IGES READ FILE="engine.igs"LEVEL=10,15& PART_NAME=.coupe.block
7. A subset of the geometric entities read by the IGES translator may be converted to outlines and markers in Adams View. Refer to the table below for a complete list of entities that may be translated into outlines and markers or polylines.
If CREATE_GEOMETRY is specified with the value 'outline', the entities listed below will be translated into Adams outlines with a marker created at each vertex. These markers will have an orientation parallel to the lprf of the PART selected in the PART_NAME parameter.
If CREATE_GEOMETRY is specified with the value of 'polyline', the above mentioned entities will be translated into Adams View polylines. No markers are created when polylines are generated.
Generating outlines has the advantage of having markers created at each vertex. These markers are standard Adams View markers that may be used for the definition of constraints, forces, mass properties, and other Adams View geometry. The outlines and markers may also be written to an Adams data set file. The disadvantage of using outlines is the increased memory requirements. Geometry translated to polylines will not have markers and requires about one third of the memory to store the equivalent outline. Polylines are not written to an Adams data set file.
In addition to the entities listed below, outlines may be created for any geometry or annotation entity that results in a linear approximation of two points. In this case, a line is created.
Outlines may also be created for surfaces that are polygonalized.
IGES ENTITY | TYPE NO. | CONVERTED TO Adams View Object |
|---|
Circular Arc | 100 | Arc, Circle |
Composite Curve | 102 | Polyline |
Conic Arc | 104 | Polyline |
Copious Data | 106 | Outline or Polyline |
Centerline | 106 (20-21) | Polyline |
Section | 106 (31-38) | Polyline |
Witness Line | 106 (40) | Polyline |
Plane | 108 | Outline or Polyline |
Line | 110 | Outline or Polyline |
Parametric Spline Curve | 112 | Polyline |
Parametric Spline Surface | 114 | Polyline |
Point | 116 | Marker |
Ruled Surface | 118 | Outline or Polyline |
Surface of Revolution | 120 | Cylinder, Outline, or Polyline |
Tabulated Cylinder | 122 | Cylinder, Frustum, Outline, or Polyline |
Rational B-Spline Curve | 126 | Polyline |
Rational B-Spline Surface | 128 | Outline or Polyline |
Offset Curve | 130 | Polyline |
Offset Surface | 140 | Outline or Polyline |
IGES ENTITY | TYPE NO. | CONVERTED TO Adams View Object |
|---|
Boundary | 141 | Polyline |
Curve on a Parametric Surface | 142 | Polyline |
Bounded Surface | 143 | Outline or Polyline |
Trimmed (Parametric) Surface | 144 | Outline or Polyline |
Angular Dimension | 202 | Polyline |
Curve Dimension | 204 | Polyline |
Diameter Dimension | 206 | Polyline |
Flag Note | 208 | Polyline |
General Label | 210 | Polyline |
General Note | 212 | Polyline |
New General Note | 213 | Polyline |
Leader (Arrow) | 214 | Polyline |
Linear Dimension | 216 | Polyline |
Ordinate Dimension | 218 | Polyline |
Point Dimension | 220 | Polyline |
Radius Dimension | 222 | Polyline |
General Symbol | 228 | Polyline |
Sectioned Area | 230 | Polyline |
8. The default scale factor is 1.0. If the scale factor of 1.0 is used, the geometry created in the Adams VIEW will be the same size as the geometry in the IGES file. A scale factor less than 1.0 will reduce the size of geometry and a scale factor greater than 1.0 will increase the size of the geometry. For example, assume the scale factor specified is 0.5, a cylinder of length 2 meters and diameter .5 meters would be translated to Adams View with the length of 1 meter and diameter of .25 meters. The distance from geometry to the RELATIVE_TO coordinate system will be scaled accordingly. If the previously mentioned cylinder was located at 3,2,0 in the IGES file, it would be located at 1.5,1,0 after it is translated to Adams View.
The orientation of the geometry is not affected by the SCALE parameter.
9. The following is an example of a 5 X 3 mesh.
_____________________
: : : : :
: : : : :
: : : : :
:_______:_____:____:____:
: : : : :
: : : : :
:______:____:____:___:
The minimum mesh is a 2 X 2 which will display only the boundaries of the surface. If the MESH_DENSITY parameter is not specified, the mesh values will be calculated by the IGES translator based upon the tolerance specified with the TOLERANCE parameter and the surface will be polygonalized. For polygonalization, the surface is sampled at several U/V rulings based on the surface type. The ruling that generates the most points at the specified tolerance in the U and V direction determines the polygon density for the surface. For certain surface types (e.g. NURBS) a maximum sample is used to reduce the approximation time for polygonalizing high order surfaces. This maximum is currently being set to 4 in each U/V direction.
It should be noted that specifying a mesh requires less computation than letting the translator default to a polygonalization (i.e. not setting the MESH_DENSITY parameter), but the polylines generated for a mesh may not be shaded in Adams View. The polylines generated for a polygonalization are closed (polygons) and therefore, may be shaded in Adams View.
10. This tolerance is the measure of the midpoint chordal distance from the approximated curve/surface to the true curve/surface.
+ + +
+ | +
+ |tolerance +
+ ___________|_____________+
+ /
+ /
+ /
+ / + = true curve
/
+ / __ = approximate curve
/ /
+ /
/
+/
Caution should be used when specifying the TOLERANCE parameter. Since you specify the tolerance value, advance knowledge of the units and size of the geometry in the IGES file is necessary. If the size of the geometry in the IGES file is not known the geometry translated to Adams View may be created too coarse, or worse, too fine. A tolerance that is too fine can potentially cause the IGES translator to use excessive CPU and memory.
The TOLERANCE parameter becomes more significant if the MESH_DENSITY parameter is not specified. If the MESH_DENSITY parameter is not specified, the IGES translator will polygonalize any surfaces encountered in the IGES file. If the IGES file contains a large number of surfaces, the IGES translator might generate a large amount of data, degrading the performance of Adams View.
If the translation appears to be taking too much time, try increasing the value specified for the TOLERANCE. Try reading the IGES file with the TOLERANCE increased by a factor of 10. If the speed degradation is caused by a tolerance that is too fine, you will see a dramatic improvement with a larger value specified for the TOLERANCE parameter.
The tolerance reported in the log file and in the LIST_INFO is the tolerance of the data defined in the IGES file. This is the maximum tolerance available in the IGES file and is usually too fine for efficient translation to Adams View. It is recommended to try a tolerance several orders of magnitude greater than the tolerance specified in the IGES file.
11. The coordinates specified by the LOCATION parameter can be relative to any other coordinate system defined in the Adams View model (See the RELATIVE_TO parameter for this command).
By default, you supply Cartesian (x, y, z) coordinates. You may use the 'defaults units coordinate_system_type =' command to change this convention. For example, selecting 'cylindrical' means you will subsequently be supplying r, theta, and z coordinates.
12. The orientation coordinates can be relative to any other coordinate system defined in the Adams View model (See the RELATIVE_TO parameter for this command).
Adams View will orient the coordinate system by starting from the initial coordinate system and applying three successive rotations.
Depending on the convention you have selected, the rotations may occur about space-fixed or body-fixed axes in any meaningful combination of the x, y, and z axes.
By default, you supply Euler (known as body313, or body-fixed z, x, z) angles. You may change this convention with the 'DEFAULTS UNITS ORIENTATION_TYPE=' command. For example, selecting SPACE123 means you will subsequently be supplying space-fixed x, y, and z, angles.
AdamsAdams View applies your orientation angles starting from the coordinate system you identify with the RELATIVE_TO parameter. The default for the RELATIVE_TO parameter is the default coordinate system.
Refer to the Appendix on "Specifying Locations and Orientations in Adams View" in the Adams View Users Manual for more information on the ORIENTATION parameter.
Tip: | If you type a "?", Adams View will list the parts available by default. |