              EDSMAC4 Version 7.21 Patch Release Notes
                          DATE: 11/03/2011
       (C) Copyright 2011, Engineering Dynamics Corporation

THIS FILE CONTAINS IMPORTANT INFORMATION CONCERNING THE LATEST
VERSION OF THE EDSMAC4 SIMULATION MODEL. PLEASE READ THE ENTIRE
FILE VERY CAREFULLY BEFORE USING YOUR EDSMAC4 SOFTWARE.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Current Software Version:

	PROGRAM	         VERSION
	EDSMAC4	   	  7.21

This file has one part:

PART     CONTENTS
 1       Changes to EDSMAC4 software since the previous version (7.20)

===<Part 1: Changes to EDSMAC4 Software>==============================

Section A: Enhancements
1.  CollisionData are now calculated after the final acceleration for
    each integration timestep, rather than 4 times per timestep. The
    additional calculations were not required. As a result, execution
    speed is increased during the collision phase.
2.  The CollisionData routine is no longer executed after separation,
    resulting in significanly faster execution of the post-collision
    phase.
3.  The Environment Data output report now includes a table of terrain
    data for each type of surface (Road, Friction Zone, Water). Each
    table includes the number of polygons, the friction multiplier, 
    and the size of the region. The Environment Data output report 
    also includes the Environment Name, Time, Date and Terrain 
    Filename.

Section B: Bugs Fixes
1.  The CollisionData routine has been corrected to fix several 
    problems. These issues are described in detail in a document 
    titled "EDSMAC4-DamageStudio-Memo.pdf" This document is included 
    along with this patch. (It also resides in the EDC Website - 
    HVE FAQ Knowledge Base - Physics Programs - EDSMAC4.)
2.  EDSMAC4 was calling the HVE Driver Model incorrectly. This could 
    cause the simulation to terminate needlessly with a message, 
    "Driver Comfort Level Exceeded." The message also potentially 
    over-wrote other fatal errors that may have occurred in the 
    collision routine ("Too Many Collision Vectors"). These problems 
    have been corrected.
3.  The Driver Data output report incorrectly displayed the steer
    angle table if the AT Steering Wheel option was selected. This 
    problem has been corrected. (The actual steer angles used by the 
    simulation were correct and not affected by this issue.)
4.  The Vehicle Data output report Inter-Dual Spacing and following 
    results were incorrect if a vehicle in one column of the report 
    had dual tires and the other vehicle didn't. This problem has 
    been corrected.
    
Section C: Other Changes
(none)

******* End of EDSMAC4 Version 7.21 (11/03/2011) Release Notes *******