DXF Files
With the prevalence of use of CAD drawing tools for creation of scene diagrams, a utility has been added to allow you to browse existing DXF files and convert the information in the DXF files to the smac Graphics (msmacgr)/smac Animation (mGraphics) .SCE (Scene) file format
The .SCE file created by the Import DXF file command can then be added to any graphics input file by inserting:
Include=filename.SCE
which will then display the graphics each time you run either of the graphics programs.
This option has only recently been added and currently only converts the line information from ASCII DXF files (Please note that some CAD programs have an optional binary DXF file format, this format is currently not supported. Please be sure to save ASCII DXF format.)
Future releases may utilize the DXF file directly and/or allow the conversion of all the information in the DXF file to SCE file information.
For further information on the SCENE file format, please see SCENE OPTION INPUTS section in the m-smac Graphics and Animation Manual. For further information on the Include= command, please see the OPTION=, INCLUDE= COMMANDS section in the m-smac Graphics and Animation Manual.
For additional information please see the section Import DXF Files.
Charts & Charts Help
The Charts function is a new addition to msmac. Please see Charts in the What’s New for an explanation and a step by step introduction to using the Charts feature.
smacthp
The SMACTHP option allows the monitoring of the acceleration and speed change of m-smac reconstructions at any arbitrary position on either vehicle. The program name was an acronym for SMAC Time History Plot, which reflected the initial use of the program to create Calcomp plots on mainframe and mini computers.
With the move of SMAC to PC's and the prevalence of sophisticated spreadsheet programs which can easily create customized graphics plots, the program now creates a Comma Delimited text dataset (with suffix CSV) for importation into any spreadsheet type program.
Please see SMACTHP Example with RICSAC2
Marquard
An analytical procedure for approximating the linear and angular velocities of a vehicle at the start of its motions subsequent to a collision, which was first defined by Marquard in Reference [1], and which served as a starting point for corresponding aspects of the CRASH computer program (Reference [2]). The cited procedure takes into account the fact that the linear and angular (i.e., yaw rotation) displacements of a four-wheeled vehicle subsequent to a collision occur under conditions of intermittent deceleration when the wheels are free to rotate. By approximating the linear and angular deceleration rates of a vehicle with either (1) all wheels freely rotating or (2) all wheels locked during the different phases of a spinout motion, Marquard developed approximate relationships for the relationship between the total linear and angular displacements during the travel from separation to rest. He then estimated the corresponding linear and angular velocities of the vehicle at separation from its collision partner, for two cited cases of rotational resistance at the wheels. The procedure has been generalized to include intermediate conditions of rotational resistance at the wheels.
Combined Rotation and Translation
Subsequent to Collision