msmac3D Now Uses Vehicle Shape, Not Rectangles

General questions on the SMAC, msmac3D and other Collision Simulation programs
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MSI
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msmac3D Now Uses Vehicle Shape, Not Rectangles

Post by MSI »

Some SMAC users have encountered issues with the original SMAC definition of rectangular vehicles.
Particularly In low speed impacts.
  • While SMAC has decades of proven validation and correlation with real world crashes using the rectangular definition of the vehicle,
  • The timing of initial contact can be an issue to explain (forces before the rounded corners touch!).
In response
  • McHenry Software has modified msmac3D (on option choice) use the actual vehicle shape of each vehicle for contact detection.
The updates will be delivered to all msmac3D licenses shortly with many additional enhancements, etc.
stay tuned!


With a rectangle representation, the vehicles detect contact at 0.024 seconds early and the DeltaVs are only slightly changed:
deltaV comparison.png
deltaV comparison.png (20.87 KiB) Viewed 345 times
figure below: comparison of old vs polygon definition, note the magenta rectangle is for comparison
rectangle v vehicle shape.png
rectangle v vehicle shape.png (630.25 KiB) Viewed 345 times
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MSI
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Re: msmac3D Now Uses Vehicle Shape, Not Rectangles

Post by MSI »

Here's a better video display of the new msmac3D shapes
NOTE: the below graphics have a dashed white line vehicle outline display which is optional and for illustration purposes only
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MSI
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Re: msmac3D Now Uses Vehicle Shape, Not Rectangles

Post by MSI »

HOWTO Video with links to specific tasks now uploaded here: Also repeated below:
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MSI
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Re: msmac3D Now Uses Vehicle Shape, Not Rectangles

Post by MSI »

July 29, 2021: Update to Polygon
Couple changes to the option to use the polygon periphery for the collision partners.
  • We added veh3 to also have a polygon periphery
  • We added the option to turn off the polygon periphery definition
    • set field 9 of input card 13 to < 1 (for veh1/Veh2 collision interaction)
      Turn off Polygon.jpg
      Turn off Polygon.jpg (8.6 KiB) Viewed 90 times
      and field 9 of input card 98 to < 1(for veh2/Veh3 collision interaction)
      Turn off PolygonV3V2.jpg
      Turn off PolygonV3V2.jpg (7.34 KiB) Viewed 90 times
  • To check/display the actual polyline used
    • In 3D graphics to turn on a display of the polygone defintion, select the Veh menu:
      Us Poly Menu with display.jpg
      Us Poly Menu with display.jpg (19.13 KiB) Viewed 90 times
      For 2D graphics we have added a Poly button which displays the polygons for each vehicle
      Poly display 2D.jpg
      Poly display 2D.jpg (47.16 KiB) Viewed 80 times
      (not using the LoadOb Veh1, 2 or 3 you can individually load these files too)
      When you choose the polygon option 2 or 3 files are created in the project directory
      • vehicle01poly.veh
      • vehicle02poly.veh
      • vehicle03poly.veh
NOTE:
  • If you are using the 2D graphics and use the POLY button AND are using an SA5 input file (you don't need an SA5 file)
    The Poly button load (or load VEH/SCE objects interactively) will reset at the cycle/end of run/restart of display at 0.0
    • to avoid the reset for polygons/etc
      include these lines in the sa5 input file (and again you do not need to use an SA5 file)
      You can by including this in the inputs:
      • include=vehicle01poly.veh
        include=vehicle02poly.veh
        include=vehicle03poly.veh
      before the lines in your sa5 file:
      • OPTION=END
        3.
For additional information see Help->smac2D graphics or online here SmacGraphics2D manual section on include command
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Question? Comment? Please email us (all communications considered confidential)
(c)McHenry Software, Inc ALL Rights Reserved.
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