Can someone give me a good explination on what the Bearing of Vehicle Number means in the surface tracking manager in Dynamite SIM? I can’t get my cars to not jump up to the bridge above them….  AGHHGHHHHGGG this is really upsetting because there is no tutorials on how to do an animation with a bridge going over a road….

Some information -
VISSIM data imported to a model in MAX using DSIM. 
Model has a bridge going over another road….cars are jumping up to the bridge.
The bridge is a seperate object.

Bearing means the direction of travel of the vehicle at any given moment in time, measured in degrees from north.

So east would be a bearing of 90 degrees, south would be 180 degrees, south-west would be 225 degrees and so on.

Let’s say that when vehicles travel under the bridge they are traveling south west, and when they are travelling OVER the bridge they are travelling (approx) east.  In this case I would restrict the application of surface tracking from the surface of the bridge, so that it is only applied when vehicles are travelling between a min bearing of (say) 75 degrees and a max of (say) 105 degrees. This would prevent any vehicles that are travelling under the bridge from having that surface tracking instruction applied.

Because of this, you may wish to carry out the application of surface tracking in a number of steps. First, apply it from the ground surface to all vehicles travelling in all directions. Then, apply surface tracking form the bridges - and that’s when you need to limit it by using the min/max bearing.

In that second pass, the surface tracking will only be updated when each vehicle passes over that bridge geometry, and only if it is travelling in a direction/bearing between the specified min/max.

You should also check the material IDs on your tracking surfaces. Dynamite SIM only picks up mat IDs between 1 and 99 in Version 1.5 or earlier. All other faces will be ignored.

You also need to ensure that the direction of the normals on the faces you are tracking are correct. If they are “flipped” (facing into the ground) they will also be ignored.

I hope this helps.

OK sure,  I am getting better results - however -

What about a bridge that does almost a 180 degree turn? (Dark Blue Bridge in my attachment) I am going to put a min/max from 290 to 160.  My Min/Max uses degrees that the cars underneath are also using because the base traffic uses 0 to 360.  Do I need to split up the lower most geometry (ground) into separate objects to also have a seperate min/max?  I am still getting jumping cars there….

You can’t use a min of 290 and a max of 160, because it won’t actually pass through 360.0 as I understand it.

You should do this in two passes 290-360.0 and 0-160.

Could you post an image of your model in plan/top view, because I’m unable to understand which way is north at the moment.

here is a top view with direction of traffic.

Wouldn’t an easy fix just be change the code so that a car can’t drastically change in the Z value? ....for instance every foot travelled in the x,y limit the z to 6 inches. These cars are jumping 20 feet up in the air.  Not good.

There is no way to have a angle that is specific for one bridge that the other roads are not using.  If I change one of the bridges angles, than the other cars on different roads start jumping up to the bridges.  I could see how this would work if you had a perfect crossing intersection….but that hardly happens in our world of complex highway design.

I really need to get this working. This job was sold on photo-realistic simulated traffic. 4,800 dollars is quite a bit of money to have this plug-in not work correctly.  Is there anyone in the states I could talk to or hire out for a day to have help me out on this?

David - I wouldn’t jump to the conclusion that it’s not working properly. If you send the dataset through to me I’m more than happy to run through the surface tracking process for you here.  Send it through to our support e-mail address, referencing this forum thread.

OK, after cutting up my file 4 different ways and doing the surface tracker in a very specific order(two days later)....I think I finally have found the right combination….

ATTACHED PIC has the numbers for my min/max for the new objects.  CAR jumping is GONE(yeah!!!)....I do however have cars getting loose….looks like they are skidding on ice or lost a tire on turn 4 at Daytona.  Does that mean I need to add more degrees to my min/max?  it only happens on the small bridges…the two yellow ones…

Any ideas?

What do you mean by cars “getting loose”? Can you clarify that one?

Glad to hear that you worked out the surface tracking process in the end.

Sorry, The back end of the car is sliding…rotating.  Attached is a screen shot of the car sliding.  Almost every car does this when it gets closer to the bridge….

Once it gets closer to the end of the bridge it straigtens out.

That’s weird. I think I’ll need to take a look at the max file and fzp file to work out what might be happening there. Is it something you can share with us via e-mail?

just sent you the file Bruce.

geardaddy1 - 26 January 2010 09:10 PM

Sorry, The back end of the car is sliding…rotating.  Attached is a screen shot of the car sliding.  Almost every car does this when it gets closer to the bridge…. Once it gets closer to the end of the bridge it straigtens out.

This appears to be a 3ds Max related issue, but having investigated it here with your scene file I have a workaround for you.

Try typing the following at the MaxScript command prompt in the scene that contains your sliding vehicles, and after your surface tracking operations are complete.

Does this solve the problem?