Scott Dombrowski Posted March 13, 2019 Share Posted March 13, 2019 Starting a new topic so I don't hijack the other thread about Spline IK. This is about finding solutions for getting tractor trailers to accurately offtrack as they go around curves (where the back wheels take a different line than the front wheels). Here's what Chris said in the other thread about importing traffic data from Vissim: Not sure this qualifies as a "good" solution, but we use PTV Vissim for our traffic simulations and when you specify an HGV (semi) with a trailer, the file that's imported brings in blocks representing the semi(s) and the trailer(s). We then are able, via Civil View (this is MAX 2016), to substitute in an actual semi model for each semi block, then I clone and align a trailer to the trailer block(s) and it works/offtracks. So essentially with this method, the only thing I'm doing is clone-align and that's it. It's not perfect unless you have the exact trailer size and exact pivot point on the back of the semi...so the provided example is a little off but with some tweaking, i think I could get it spot on. Here's a quick animation, notice how the semi is centered and the back of the trailer the wheels are on the line (a chopped down old file so excuse the mess): The main problem with this is...you have to have PTV Vissim software and know how to use it. It's not a program you can really pick up without training or an understanding of traffic operations/planning, all our traffic engineers that use it have to go to training. I don't know how to use it other than take what is given to me and export out the files I need. This is aimed mostly at Chris, but if anyone else wants to chime in, that'd be great. Our traffic group uses PTV Vissim and that's where I get my traffic data. In the exports I got, the HGV boxes never came with trailers though. Sometimes there wasn't even a gap large enough for a trailer so I'd have to delete the car behind the HGV so it wouldn't be in the same spot. I don't think we have a license in this office for me to try it out, so I'll have to talk to the traffic group to see if they can get trailers in the export. That would save all sorts of headaches. To that end, are you able to get cars that smoothly turn corners? It depends on the simulation, but I'll sometimes get an export that has cars banging around a curve, as if the path they're following doesn't have enough vertices. I'm not sure if this is something that can be smoothed out in Vissim, or if that's just how Vissim is. Link to comment Share on other sites More sharing options...
Chris Harris Posted March 13, 2019 Share Posted March 13, 2019 Hi Scott, You can definitely get trailers in there; you can have boxes behind the HGV's that represent boats, semi-trailers...a lot of things. It'll look like a small box in front (even though its large relative to a normal car box) of a larger box that's the trailer...so they definitely need to look into that. Also, the turning corners...this is like the 1 thing I know how to fix in Vissim! You are correct, its a vertex thing. Whoever makes the network or link (can't remember what the actual term is for the road), they are only clicking in a rough manner to make a corner...which is fine but then you can click the spline acting as a corner and right-click and click on "Generate Spline,", which brings up a menu and it asks you how many points you want in between the vertices, and that smooths it out so it doesn't look like its banging off of an invisible guard rail. Link to comment Share on other sites More sharing options...
Chris Harris Posted March 13, 2019 Share Posted March 13, 2019 In the exports I got, the HGV boxes never came with trailers though. Sometimes there wasn't even a gap large enough for a trailer so I'd have to delete the car behind the HGV so it wouldn't be in the same spot. This happens because not all HGV's are the same. For example, some are the equivalent of semi's with a trailer, others are just large trucks...such as a large moving van...so technically, there is no trailer in this case so if you add one, yes, the cars behind will "run into" the trailer, which shouldn't be there. Can ya tell I've been banging my head against the wall with Vissim for years??? Link to comment Share on other sites More sharing options...
Scott Dombrowski Posted March 14, 2019 Author Share Posted March 14, 2019 This is great info, thanks Chris! I'll bring this up with our traffic people next time. We might have another animation coming up in a month or two, so I'll probably have more questions then. Thanks for your help! Link to comment Share on other sites More sharing options...
Ernest Burden III Posted March 14, 2019 Share Posted March 14, 2019 Our traffic group... You have people for just traffic? Link to comment Share on other sites More sharing options...
Chris Harris Posted March 14, 2019 Share Posted March 14, 2019 Ernest, I know your question was directed at Scott, but I know in my firm's case, we have 8 employees in our traffic group. Our surface transportation group is probably in the 100's. That's everyone from the traffic group to bridge engineers to planners to CAD draftsmen to public involvement. Firm of 500+ people. Link to comment Share on other sites More sharing options...
Scott Dombrowski Posted March 15, 2019 Author Share Posted March 15, 2019 we have 8 employees in our traffic group. Our surface transportation group is probably in the 100's. That's everyone from the traffic group to bridge engineers to planners to CAD draftsmen to public involvement. Firm of 500+ people. Similar situation here, though I don't know exactly how large our traffic group is. Our firm is about 700 people across about 20 offices. I'd guess more than a third are in some sort of transportation discipline. I do know we have a handful of traffic engineers in each of a couple of offices who use Vissim. I wish I had a traffic animation group. That would be amazing. Link to comment Share on other sites More sharing options...
Chris Harris Posted March 15, 2019 Share Posted March 15, 2019 I wish I had a traffic animation group. That would be amazing. That's mostly all I do is traffic animations. Gets old in terms of not much variety, but I do get to go out and shoot photos for other types of projects for photo simulations: wind/power/transmission line projects...so that's nice to travel and break up the monotony. Link to comment Share on other sites More sharing options...
Ernest Burden III Posted March 15, 2019 Share Posted March 15, 2019 I wish I had a traffic animation group. That would be amazing. Ah, as in traffic engineering and design and such. I was thinking you were in a rendering company. I recently did a 20 minute animation showing two bridges, one getting a span replaced and the other completely replaced by an A and B scheme on an existing or adjacent alignment. I worked for the engineers. I had to show traffic patterns, lane adjustments during work, detours around a region. And, I had to figure that out myself. That explains my awe at the idea of a 'traffic group'. I can also see a large enough viz company benefiting from a dedicated team for showing urban traffic, and people traffic. There is a great looking plug-in for Cinema4D called RealTraffic https://c4dplugin.com/product-rt , I'll have to try that next time I need to show traffic over miles of NYC when a bridge gets replaced. Link to comment Share on other sites More sharing options...
Scott Dombrowski Posted April 10, 2019 Author Share Posted April 10, 2019 Hi Scott, You can definitely get trailers in there; you can have boxes behind the HGV's that represent boats, semi-trailers...a lot of things. It'll look like a small box in front (even though its large relative to a normal car box) of a larger box that's the trailer...so they definitely need to look into that. Also, the turning corners...this is like the 1 thing I know how to fix in Vissim! You are correct, its a vertex thing. Whoever makes the network or link (can't remember what the actual term is for the road), they are only clicking in a rough manner to make a corner...which is fine but then you can click the spline acting as a corner and right-click and click on "Generate Spline,", which brings up a menu and it asks you how many points you want in between the vertices, and that smooths it out so it doesn't look like its banging off of an invisible guard rail. Chris- I passed along your tip about smoothing out the corners to our traffic engineers and that worked great, so thanks for that! I just got a .fzp from VISSIM for a new roundabout where they want to show buses and WD-62 sized semi-trucks using the roundabout. Civil View sees Cars, Buses, and HGVs in the .fzp and brings everything in as the car-sized boxes. I swapped out the buses with the built-in GMC Bus model, and they appear to offtrack properly. The issue is that the HGVs only come in as one box, not two separate boxes for the truck and trailer. I spoke with the traffic engineer and he sent me a video from VISSIM that shows the truck and trailer correctly offtracking around the roundabout, so it seems like an issue with how the data is exported/imported. Do you have any suggestions for how he should set up the export so that the truck and trailer come in as separate boxes? Link to comment Share on other sites More sharing options...
Chris Harris Posted April 10, 2019 Share Posted April 10, 2019 Honestly...no. Not sure what to tell you there Scott. The files I've received from my traffic engineers just seem to work for me. I will check with someone. I'll get back to you shortly. Link to comment Share on other sites More sharing options...
Chris Harris Posted April 10, 2019 Share Posted April 10, 2019 Honestly...no. Not sure what to tell you there Scott. The files I've received from my traffic engineers just seem to work for me. I will check with someone. I'll get back to you shortly. Well I guess I won't...at least today. The person I need to ask, of course he's out today. Link to comment Share on other sites More sharing options...
Scott Dombrowski Posted April 10, 2019 Author Share Posted April 10, 2019 Well I guess I won't...at least today. The person I need to ask, of course he's out today. No worries. Thanks for looking into it! Our traffic engineer is going to try a couple of things later today. I'll report back when I get some results. Link to comment Share on other sites More sharing options...
Scott Dombrowski Posted April 15, 2019 Author Share Posted April 15, 2019 Well I guess I won't...at least today. The person I need to ask, of course he's out today. Ok, I've gotten a couple of .fzp files that are supposed to have the cabs in one file and trailers in another, but when I import both files the boxes that Civil View creates are on top of each other. Is your traffic guy in today? Link to comment Share on other sites More sharing options...
Chris Harris Posted April 15, 2019 Share Posted April 15, 2019 It should just be one file with both the HGV and Trailer in it and look something like this within Vissim. Is that what their file looks like in Vissim? Click small file image above. Link to comment Share on other sites More sharing options...
Scott Dombrowski Posted April 15, 2019 Author Share Posted April 15, 2019 That's what I figured. I've pointed him towards this thread, so hopefully that image will help. I'm out of the office for a couple of weeks, so I'll check back in then. Thanks again for your help! Link to comment Share on other sites More sharing options...
Scott Dombrowski Posted May 10, 2019 Author Share Posted May 10, 2019 Just an update on this. We never did figure out the VISSIM workflow. I ended up purchasing Craft Director Studio which worked great. As a bonus, it accurately handled the trailer wheels going up on the truck apron of the roundabout, which I don't think VISSIM / Civil View do on their own. Once you rig your high-poly truck model, you can either drive it manually (keyboard, steering wheel controller, joystick, etc.) or have it go in "autonomous mode" where it follows a path or another object. I just linked it to the VISSIM HGV box and it worked great. I'll see if I can get a video up once it goes public. Link to comment Share on other sites More sharing options...
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