My Citty Traffic review

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paulov
Posts: 6
Joined: Tue Oct 06, 2009 12:34 am

My Citty Traffic review

Post by paulov »

Dear Coders


I'm a Civil Engineering student from BCN, I've tested your demo version of City Traffic and I've taken some time to take notes and develop this document which is my impression of the application.

I would not have take the time to do this if I didn't believe that his application has something really interesting to offer.


This has been the first time I feel I can massively populate roads with a realistic behavior system even if I've found several black points.

In this document I've focused in the points I believe need improving.


INDEX

1 CAR PLACEMENT

2 ROAD SETUP&DESIGN
---*GENERATION
---*ROAD TRAFFIC DENSITY PARAMETER

3 MOVEMENT CALCULATION

4 BEHAVIOR.
---*VEHICLE TYPE RESTRICTIONS.
---*ROUNDABOUTS.
---*PARKING TIME CONTROL.

5 MISCELANEOUS

6 PERFORMANCE ISSUES

7 DEMO VERSION LIMITATIONS

8 LICENSING




1 CAR PLACEMENT

Automatic car setup is superfast and works fine. Took me some time to understand that form top view should look as in the schema :P



I feel really uncomfortable when adding the definitive vehicles and setting its final count. Its a very messy process, and is one of the weakest point of the application.

For this process I think that an asset browser like tool is the right way to go.

The car placement window should point to a directory of .max files that would host already rigged vehicle(s). One file one car or one file with multiple cars.

In the asset control window, in one column should appear the available cars grouped by type, Car-Truck-Bus and in the right the ones that have already been selected to be in that scene.

Till here, car model selection. Now, car count.
Duplicating vehicles, making them unique... its a time consuming and boring job, especially if you want to have control over the proportion betwen car models , car types etc...

There should be two stages

1) Global Vehicle proportion in %. i.e: 80% Cars 13%buses 7% trucks.

2) Could be set as random but should be also selectable. From the selected models (right column), for each type, control the presence for each model in the scene.

i.e: for cars if there are 10 models selected set which percentage has each one.

Till here, Car model selection, vehicle mixture proportions.

Finally, the ability to set globally the number of cars; this could be not necessary if the per road vehicle density parameter is added, but even if these parameter was present total number could be useful as the vehicle density could represent the maximum admissible load of the road.


The car placement could look something like this.

https://www.3am-solutions.com/products/d ... cement.jpg




2 ROAD SETUP&DESIGN

*GENERATION
When you generate a road from a spline, general parameters are applied to the road that covers all the length of spline such min-max speed etc... right.

But later, when you whant to edit these parameters you only cant edit them locally where arrow-shaped control points appear, editing them one by one, this is not so good.

You should be able AT LEAST to edit parameters of all the selected control points, overwriting the parameters values entered as new.

I believe that the application "knows" where a road generated from a spline starts and ends as it assigns different colors to its axis (don't remember this clearly I'm typing from ubuntu), so, editing that road globally should also be supported.

Connected to this, I found that is some cases it was difficult to connect a road to another due to the absence of control-arrows, being forced to weirdly prolongate the joining road till position fo the main roads control arrow. The ability to add a control arrow at a determinate length (doing it graphically of course) would be very helpful.


*ROAD TRAFFIC DENSITY PARAMETER

As I saw no parameters to control the vehicle density of a road I made a simple test. I placed a 5 km length 4 lane highway. Drawn a exit and and access to it and placed a vehicle density of 320 dummy cars. As I spected the access & exit routes where as overloaded as the highway, which looked very unrealistic.
should look something like this:
https://www.youtube.com/watch?v=6QdGHWrG ... re=related

So, each road should have a traffic density parameter, this way a highway exit should have few cars exiting, or a exit to downtown would appear collapsed or so.

Also a residential neighborhood should have a main street an al other secondary streets so nearly have no traffic. This parameter would increase the realism considerably.





3 MOVEMENT CALCULATION
Even if I've seen it in the documentation, have not seen in the demo version, may be the demo is a bit outdated.

Its about calculating only the movement of the vehicles as if they where blocks (the wheels could roll) but without dynamics. This would be interesting for preview purposes as the full calculation with high number of vehicles takes a whole night for high vehicle number and a some thousand frames.




4 BEHAVIOR.



*VEHICLE TYPE RESTRICTIONS.

Add vehicle restrictions to specific road lane.


1) If the highway has 3 lanes, the one in the left cant be accessed by the trucks. This time it could be restricted using speed parameters by leaving the min speed of the lane at 100 an the max of the truck at 90.



2) But there are other situations that at this moment cant be simulated.
2.1 ) Exit from highway to a residential area. No truck should take this one, as streets will be narrow, and there are no reasons for trucks to be there.
2.2) A main street in a city can have trucks, but some kind of streets only cars.
Also connected to this the % of Car-Bus-truck of the road could be parametrized, always respecting the maximums established by the asset placement tool.

As in this videos trucks never go to the maximun left lanes.
https://www.youtube.com/watch?v=ggzmQo_q ... re=related


*ROUNDABOUTS.
Didn't I saw cars doing the roundabout once and again?. A car entering a roundabout should exit prior to going back to where it entered.


*PARKING TIME CONTROL.
I've read in the forum that this is a random time! . I don't see why this is a good thing. I believe it would be much more usefull to have it controlled by adding a Parking time in minutes + random factor.
This way, the motion would be much more realistic and apart from parking other situations could be simulated like a toll plaza of a highway. In a toll plaza you could place a 0.5min stop fro manual payment 0.2 for card and no stop for Tag payments.... plus a random factor. I believe this would be a nice feature.
You could simulate a petrol station too.


*The collision object. Only as comment, even if I've not tested, I believe that the collision objects could be used to emulate the effect of the a continuous line in the ground, avoiding the vehicles to cross to the other lane while the line is on the ground that for the application would be that line extruded as a plane.



5 MISCELANEOUS



*When no surface is assigned you can see the distribution of the vehicles along the roads by clicking "trace" button. Even if no motion calculation is done this is feature is cool enough to be added as a button like "preview". This way you can have an idea of the vehicle density.
This feature should be available even if the surface is already selected.





*When going back to utilities menu--> city traffic , the position of toolbars is reseted. What was minimized now is maximized.. and have to minimize & scroll again. This is a pain when generating roads as I usually move from the utilities menu.

When picking splines for road conversion, the tool deactivates after clicking. If you have 30 splines to convert you've to click the button 30 times.... you get me..?

*Just as and idea when for when the app is more mature.. As the app knows when the traffic light is set to Red-Ambar-Green. The trafic light element could also be added and have its lights animated according to the status. I've not played with Traffic lights yet anyway.



6 PERFORMANCE ISSUES
In a scene, if 300+ copies of a dummy are made, eve if there are not present polygonal messes, the viewport performance is drop down dramatically. I've a decent pc with 8gb Ram, HD4850 card with Phenom4 3Mhz chip and the frame rate drops to 4fps just when orbityng with no animation. If I hide the yellow boxes, the performance rises inmediatelly. How is that?!!?!
SHow stats shows no additional polycounts apart from terrain when all is on.




7 DEMO VERSION LIMITATIONS
After spending 3 hours setting a complex scene, I discovered without much happiness that all my roads where lost when reloading. Hei! at least leave a 15 day working or something!!!


8 LICENSING
Any student or educational version available? if not the request is obvious.


I honestly hope this plugin goes better and better.

Your sincerely.

Pablo Vidaurre >








*Tested under Win XP 64bits Max64bits.
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