Started by z, February 20, 2010, 07:48:37 PM
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Quote from: RippleJet on December 13, 2009, 02:03:56 AMFrom what I've seen in a couple of my cities, the destination finder works from the west to the east,probably picking the tracts (which are 4×4 tiles) in consecutive order, starting in the northwest corner,going down south, and then up to the next column of tracts.
QuoteSo we have an interesting situation in that we can decide what we want to get out of A*. At exactly the right point, we'll get shortest paths really quickly. If we're too low, then we'll continue to get shortest paths, but it'll slow down. If we're too high, then we give up shortest paths, but A* will run faster.In a game, this property of A* can be very useful. For example, you may find that in some situations, you would rather have a "good" path than a "perfect" path...
QuoteAlthough what is intruiging is your roads are not over capacity. There seems to be an invisible "line" that is stopping sims from going further, I have a feeling this is where the maximum distance of the travel is.
QuotePlease note that this modd will be less and less effective as your zoning is more and more mixed. For best results, think realistically in your zoning practices, and don't be afraid to zone vast areas of residential. If you're not seeing much highway usage after this modd, it's almost certainly because the majority of your residential zones are not separated from the majority of your jobs. We have played SimCity too long by learning to deal with the necessity to zone everything mixed in an unrealistic way. This modd frees us of that limitation.
QuoteAs we all know, commute time effects desirability enormously, and desirability is one of the key factors in determining abandonment and development. Because of this, in cities built without the modd, it is fairly common to see a redistribution of wealth classes for a year or two until things settle down. Simply let the simulator run for a couple of years and things will even out again.
QuoteI am one of the people who did a lot of work testing the commute engine, and compiled the work of simtropolis members in the 'commute time and pathfinding report' which described many issues in the commute engine. I just recently created a modd available at simtropolis which fixes the pathfinding engine so that it does find the fastest routes. Enough of the credits, I'm not trying to be conceited at all, I just want you to know I've done my homework.After four months of testing gameplay and reading about pathfinding programming, I have the following suggestions for the pathfinding in Rush Hour. I have no way of knowing which, if any of them, are included, but please consider these suggestions very seriously. They have the potential to make gameplay much better if they are implemented, or kill the fun simcity fans have with the game if they are not.Suggestions: ...***Implement a more efficient pathfinding algorithm***I have not been able to definitively prove which algorithm the sims are using, but from what I have read, it seems plainly obvious that an intersection (node) based A* algorithm would be by far the most effective and most efficient processor wise.
QuoteHello? Am I talking to a wall? Should I just stop fixing this game altogether out of annoyance that maxis doesn't care? Or does maxis admit these issues and plan to fix them?
QuoteSome response below, I know these are not ideal answers, but we did get the programmers together and go over each of the areas you raised. We do appreciate the challenge (as long as you all understand that there are limitations to any system that is trying to do over 10,000 calculations a second).
QuoteMore efficient pathfinding. We're already using a modified version of A*.
QuoteMaxisFrank, I can understand the reasoning in most of your statements. In fact I agree with alot of them. The thing we are most clamoring for is a more rational heuristic (.005 instead of .09 so sims actually use highways and such)...
QuoteBy the way, the reason why the heuristic is set at 0.09 instead of lower is for performance reasons. The lower you make this the smarter the traffic sim gets, but the longer it takes to complete a traffic cycle. If you've got a buff machine, drop it and be happy. If your machine is emitting smoke and screaming at you to make it stop, turn it up a bit
QuoteI can understand the pathfinding heuristic being set higher to speed up performance, but surely you could find a middle ground that allows for both good pathfinding and good performance? As it is now, that value is so high that pathfinding virtually doesn't exist. Sims do NOT take the fastest route to work in almost any situation; rather, they take the most direct, in terms of shortest possible distance. this results in ridiculously overused streets, crowded roads, empty highways, and underused mass transit systems.Surely there's a better way to improve performance than by crippling the pathfinder? the7trumpets' pathfinding modd doesn't have THAT much of an impact on performance... I think the worst was a 45% slowdown, and that was only with the PERFECT pathfinding mod. In my case, the slowdown was MAYBE 15%, which is MORE than tolerable since it means sims actually look for the fastest way to work instead of the most direct. Few of my streets are overcrowded, and my highways are heavily used, for the first time since I bought the game.That's what we're asking for. A fix that doesn't have to cripple the pathfinder, and allows the game to work as it was advertised by the developers (sims looking for the FASTEST route was specifically mentioned in the networks article, if I'm not mistaken).
Quote"In an area around the lot in question, the traffic on the network tile with the highest morning traffic volume is added to the traffic on the network tile with the highest evening traffic volume, and then multiplied by this coefficient to generate a 0-255 value which is then used as a desirability factor for R and C zones, and shows up in the general query as low, medium, or high under Traffic Noise or Customers."
Quote from: Trias on April 22, 2010, 04:46:22 AMDoes anybody know how big this area is? That is how many tiles away from the road are C and R zones still influenced by its traffic? Is it the same for R and C zones?
QuoteAlso is this based on the absolute traffic values or is it relative to the road capacity?
Quote from: z on April 22, 2010, 04:07:39 PMI'm not sure how big the area is, although I think I recall reading somewhere that it may be around six or seven tiles. Someone else may have a more definitive answer; that would be worth adding to to the Guide. I'm pretty sure it's the same for R and C zones, but I'm not 100% certain.
QuoteIt's based on absolute traffic values; this was determined by comparing the results using simulators with very different capacities.
Quote from: Trias on April 23, 2010, 03:06:53 AMI might do some experiments this weekend to find out, then.
QuoteIf you multiply these by the "traffic noise/customers coefficient" 0.250 you get ~153 and ~213. This is consistent with simplest possible formula for the traffic noise: Minimum of ('highest morning commute' + 'highest evening commute')*'traffic noise/customers coefficient' AND 255. With the medium bar at 153 (about 60%) and the high bar at 213 (about 83%). I will need to do more experiments with different values of the "traffic noise/customers coefficient" to confirm of falsify this simplest hypothesis.
Quote from: z on April 26, 2010, 02:59:29 AMI think that the reality is more complicated than this. No other traffic simulator has a traffic noise/customers coefficient above .128, which would imply with your formula that they should always have low customers. Yet they don't. So something else is going on here. If you really want to find out what's happening here, you need to vary the traffic noise/customers coefficient and see what happens across a range of values. That would be very interesting indeed! (And very time consuming, as well! ) I did just enough of that to get the current value; more extensive experiments may very well yield a better value.
Quote from: Trias on April 26, 2010, 04:22:41 AMReply to the italic part. No, it wouldn't. It would just mean that you need about twice as much traffic to produce the same amount of customers.
QuoteSo, I did a couple more experiments tonight with different values of the C/TN-cWith a value of .125, I found the low-med transition at ~1205 and the med-high transition at ~1715. Multiplied by .125 that is ~150 and ~214.For a value of the coefficient at .500, I found values ~290 and ~430, which correspond to values ~145 and ~215 when multiplied by the coefficient.This is all still consistent with the simple Ansatz I made before.
Quote from: captainpoof on May 02, 2010, 11:41:34 AMI've noticed that putting rails (the standard type--not GLR or any modded stuff) across roads effectively functions as a blockade. According to the route query, there aren't any vehicles on one side of the railroad crossing.But I think this only happened in my cities after I installed the NAM with traffic simulator B. I switched to A and Z, letting the game move forward by a year or two, but these simulators also had empty roads near railroad crossings. Are the simulators purposefully making the sims avoid these intersections?If they are, I'm tempted to demolish my train system--though it'll make me sad, seeing all the effort I put into them. At the same time, the sims haven't used the trains since I installed the NAM...
Quote from: z on May 10, 2010, 01:45:12 AMThis is excellent work! Your experiments were far more precise than mine, so I trust your data. Sometime in the next few days (once I recover from this NAM release), I'll incorporate your results into the main document.
QuoteIt seems to me that this would also be a useful parameter to be able to adjust in the Traffic Simulator Configuration Tool. One question I have, which I think a lot of people would want to know: When you use the higher coefficients, do you start to notice any negative effect of high noise on residences? This is much harder to quantify, since there's no number equivalent to "customers," but I haven't seen cases in which R$$$ Sims move out due to noise. Does this happen with the higher coefficients, and if so, are you able to quantify it at all? This would be very useful to know, if you have the time to check it out.
Quote from: Trias on May 10, 2010, 02:08:12 AMNote that the Zone-developer exemplars actually contain a property that claims to map traffic to desirability. Is there any reason to assume that it doesn't do what it is supposed to?
QuoteSomething I forgot to mention. Residential zones do not seem the have the same traffic noise thresholds as C zones for some reason. During my experiments I did some parallel measurements on a 1x1 R zone. The thresholds for this zone were significantly lower (by about a factor 2) then for the commercial zones customers.
Quote from: Trias on May 06, 2010, 07:36:07 AM...Thus far most my test has been done by using small zones. For 1x1 zones, the zone will get the traffic for the block in which it is located. For larger zones that have tiles in multiple blocks, the traffic appear to be taken as the traffic get for the middle tile of the zone. In the case of even number of tile in the zone, the tile to the south of the middle is taken. (The later part is still a bit speculative, and needs more testing. In particular, I do not know what happens for very large zones of say 8x8 in size.)
Quote from: Trias on May 17, 2010, 08:12:50 AMUsing a large 8x8 custom lot, I've confirmed my suspicion. Large Lots will never see high traffic.
QuoteAs to the optimal value for the customers traffic noise coefficient....128/(road capacity)
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