SoConverter Class |
Abstract base class for converting data sets into LDM format.
Namespace: OIV.LDM.Converters
The SoConverter type exposes the following members.
Name | Description | |
---|---|---|
Convert | Calls Convert((OIV.LDM.Converters.SoConverterParameters ^)nullptr). | |
Convert(String) | Obsolete. | |
Convert(SoConverterParameters) | Main converter function. | |
Equals | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) | |
GetHashCode |
Overrides GetHashCode().
(Inherited from SoNetBase.) | |
GetType | Gets the Type of the current instance. (Inherited from Object.) | |
ToString | Returns a string that represents the current object. (Inherited from Object.) |
This is the abstract base class for classes that convert existing data sets into the LDM (Large Data Management) format.
OIV.LDM.Converters.SoConverter provides powerful features including:
Command line parsing for easy creation of stand-alone converter programs.
Checkpoint and restart for interrupted conversions.
Multiple subsampling algorithms for creating low resolution tiles.
Automatic loading of any supported data format (see OIV.VolumeViz.Nodes.SoVolumeData).
Conversion of any data format by providing a custom reader (see OIV.LDM.Readers.SoVolumeReader).
Special handling to minimize disk space for "thin volumes" where one dimension is smaller than the tile size. (Currently only implemented for Z dimension.)
Optional data compression to reduce disk space.
Optional data type conversion, e.g. float to byte.
Information common to all converter classes is included here including command line, incomplete conversion, compression and subsampling. Normally you will use, for example, the derived class OIV.VolumeViz.Converters.SoVolumeConverter to convert volume data. You can also subclass from OIV.VolumeViz.Converters.SoVolumeConverter to use a custom volume reader, provide a custom subsampling method, etc.
Command Line
When used as a command line application the string should have the following form:
inputFilename [-t tiledim] [-o filename] [-O [filename]] [-m memsize] [-h] [-w B|L] [-f u8|u16|u32|s8|s16|s32|f [-r min max]] [-q] [-D] [-P portnum] [-c type] [-l level] [-C] [-s [0..N]] [-u value] [-verticalFlip]
where:
-t tiledim | Dimension of tiles. Must be a power of two. Default is 128, meaning 128x128x128. | |||||
-b bordersize | DEPRECATED Since OIV9.0, this parameter will be ignored. | |||||
-o filename | Name of created XML header ldm file. Default is inputFilename with extension .ldm. | |||||
-O filename | Name of the file containing the data. If filename is omitted, the default filename is the same as the output filename specified by the -o option, with extension .dat instead. | |||||
-m memsize | Maximum size of memory to use in MB. Default is 512 MB. | |||||
-h | Output the header only. | |||||
-w wordfmt | Indicates the target machine word format is Big Endian (B) or Little Endian (L). Default is the current machine word format. | |||||
-f datafmt | Indicates the output data format with * = 8,16,32. u*:unsigned integer, s*:signed integer, f:float. If the output data format is float, the values are mapped to the range [0-1]. Default is the input data format. | |||||
-r min max | Indicates the input data range to map to the new data format specified by the -f option. If not specified, and input type is float and ouput type is integer, the values are simply cast into the output data type. | |||||
-q | Quiet mode. | |||||
-c type | Type of compression used. See also "-l level". By default the following compression types are available:
| |||||
-l level | Level of compression used. See also "-c type". The meaning of this parameter depends on the type of compression used: |
| ||||
-C | Data integrity check. When compression is enabled using -c, adds a data integrity check value to all compressed tiles. If the environment variable LDM_COMPRESS_CHECK_CRC32 is set, data values will be checked each time they are read from disk. | |||||
-s 0..n | Specifies the algorithm used to build low resolution tiles. Available options are :
| |||||
-u value | Undefined value. The given value will marked as undefined in the LDM file. This is currently used by OIV.VolumeViz.Nodes.SoHeightFieldRender (vertices with undefined values are not rendered). | |||||
-rgba | Specifies that output will be unsigned int32 RGBA values. | |||||
-noHistogram | Disable histogram computation (conversion will be faster). | |||||
-B value | Define threshold value to generate a bitset dataset. Any value in the dataset less than or equal to the threshold will generate a zero bit. Values greater than threshold will generate a one bit. | |||||
-verticalFlip | Flip the output on Y axis. |
The return value may be one of the following:
CVT_FINISHED_WITH_WARNINGS | Some warnings occured but task complete |
CVT_NO_ERROR | No problem, task complete |
CVT_INPUT_PARAMS_PROBLEM | Input parameters problem: input filename missing, bad parameter value, or invalid option |
CVT_FILE_EXT_UNKNOWN | Unknown file type (file extension) |
CVT_CANT_OPEN_INPUT_FILE | Could not open input file (does not exist) |
CVT_CANT_CREATE_DATA_FILE | Could not create data file |
CVT_CANT_CREATE_HEADER_FILE | Could not create header file |
CVT_NOT_ENOUGH_DISK_SPACE | Could not allocate disk space for the data file |
CVT_ABORTED | Conversion has been aborted by the application, task not complete |
CVT_NO_NODE | Distributed converter cannot be used as the license does not allow any client node |
CVT_NO_LDM_LICENSE | No LDM license |
Incomplete Conversion
The converter saves the progress of the conversion in case the user wishes to abort or start visualizing the converted data or if the program crashes for any reason. In this case, the LDM files (header and data) are coupled with a completion file (name of the header file with an extension of .fcp). When restarting the converter, if the header file points to a .fcp file (XML tag <completionFilename>), the conversion will restart where it previously ended. When visualizing an incompletely converted file, it is possible to know where data actually exists by turning on the topology outlines (see OIV.VolumeViz.Nodes.SoVolumeRendering). Red outlines indicate actual data.
In order to restart an incomplete conversion, the header file must be in synch with the completion file. For this reason when writing the pair of header/completion files, the converter first backs up the pair of files before overwriting them (.ldm and .fcp with .bck extension). If the header file is lost or its size is less than the size of the backed up header file, then you can rename the backed up completion and header files to restart the conversion.
A basic command line converter program would look like this:
public class CommandLine { public static void Main(string[] args) { // Create parameter object from command line args SoConverterParameters parameters = SoConverterParameters.Create(args.Length, args); // Start converter SoVolumeConverter converter = new SoVolumeConverter(); int result = converter.Convert( parameters ); } }
You can also invoke the converter from an application by creating an instance of OIV.LDM.Converters.SoConverterParameters and setting the desired parameters. For example to convert an input file (in a format supported by VolumeViz) to LDM format with compression enabled:
SoConverterParameters parameters = new SoConverterParameters(); parameters.SetInputFileName( "filename.sgy" ); parameters.SetTileDim( 128 ); SoVolumeConverter converter = new SoVolumeConverter(); int result = converter.Convert( parameters );