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  1. DevBlog: Progress report 01/2015

    , 02-03-15 at 11:17 PM
    Hello all RoR fans!

    My name is Petr Ohlidal (a.k.a only_a_ptr) and I'd like to give you an update on RoR development in the past month. I'll also sum up all activity which has been going on since I joined the project - and there is a lot to sum up, RoR has changed signifficantly since then.

    I joined the project in fall of 2013. At the time, RoR was a dying project - the original authors left to develop a commercial BeamNG project and community had been inactive for more than 6 months or so. The last stable release was 2 years old and the new version was half-baked. I evaluated the state of the project, decided my priorities and started coding. For the first months, my effort had no visible outcome as I decided to rewrite some very internal logic, but finally I released several test builds and today, they're consolidated into a single development version which aspires for a new stable release.

    To my great cheer, my enthusiasm has sparkled a new wave of collaborative development, and today, RoR has 4 active developers:
    • Me ~ Self-invited lead coder, a code greasemonkey focused on internals and software architecture.
    • Max98 ~ Cheerful enthusiast with focus on GUI and graphics. Fixed some long standing graphic bugs.
    • Hiradur ~ Valuable compiler specialist and analyst. Keeps RoR running on Linux and inspects it with Valgrind for memory issues.
    • Aperion ~ Old community member and contributor who came back to help.

    At the moment, the development is aimed towards delivering a new stable release. This is very important to shake off the "dead project" feeling. RoR hasn't had a stable release in years and with new similarily-themed projects, BeamNG and SpinTires, it seemed that RoR will become history. That is, however, not going to happen. Not only RoR lives on, but it also stays unique among all competition. The planned release is dubbed NextStable and has a version number 0.4.5, which displays the signifficant leap from last available build This leap is well deserved, RoR has undergone a signifficant facelift and got rid of some long standing bugs which annoyed and discouraged players for too long. Also, major refactoring was done on the inside, to serve as groundwork for future enhancements and stability. This is a list of the most important archievements:
    • RoR got main menu! Until now, RoR worked in a straightforward scenario "start - select track - select vehicle - play - exit game", which wasn't really player-friendly. Also, the internal startup logic was over-complicated and slow, so it received a lot of fixes. Courtesy of Max98
    • RoR got new GUI skin. The previous "orange with bright orange" was really lame. New one comes in orange+black and really feels like a vehicle-driving game. Kudos to Max98
    • RoR got in-game configuration panels. Previously, all the configuration had to be done in external configurator, which works, but it's not very appealing to players. Thanks goes to Max98
    • RoR got a built-in editor for vehicles. Until now, modding had to be done with variety of external tools and a lot of hand-writing. However, this approach will soon be history. The editor is not fully featured yet, but it's architecture allows it to fully load/save the vehicle format and perform any modifications, with mouse and hotkeys, in an interactive environment. A primary inspiration for controls and workflow is Blender.
    • Rig definition file format (.truck) was completely re-coded. The old logic was flawed, bloated and effectively blocked any future enhancements. The new one is a separate component designed for stability and extensibility. It also allowed creating the rig editor. However, a lot of content stopped working in the process, sometimes due to bugs in new code, but often because of syntax flaws or inconsistencies and bad practices in .truck files themselves. Work is being done to fix the situation.
    • Max98 fixed two inflamous graphics bugs - shadows and skidmarks. He's also putting a lot of attention into sky, water and environment in general.

    Following is a list of things to definitely expect in NextStable:
    • It will provide a list of errors and warnings every time a vehicle spawned. This is mainly to help modders, but also to inform players of possible incompatibility of older content.
    • It will support most of the vehicles which are currently broken. Sadly, some of them will not be compatible due to legacy flaws or bad practices of mod authors.
    • Not much else to change. This is actually a good feature, because more changes would mean more waiting and I know everyone is already tired of waiting.

    Actually, if you feel like NextStable is coming out pretty slowly, it's not just you. I've been putting off the work for a long time because, honestly, bugfixing is boring and there is a lot of juicy redesign waiting to be done in the simulation code. So, instead of delivering what everybody is waiting for, I've been fiddling with the internals in my private development branches. Sorry guys. However, no more slacking off, I've published my experiments in my GitHub forks, consolidated my changes and I'm back to bugfixing.

    From now on, I'll be publishing a progress report blog post every month. This idea came from Max98, big thanks to him, a dev blog is a big step forward in presenting the project. Expect future posts to be a lot more detailed and to the point, this post is somewhat bland because it just has too much to sum up.

    Official News , Development
  2. My personal vision for Rigs of Rods

    , 01-15-15 at 03:30 PM
    With the blog section now being back alive I though I'd give it a shot and write about my personal goals for Rigs of Rods. Every developer working on an open source project usually has his own vision for what the project could become and works on things that bring it closer to that vision.

    So here it is, my vision of Rigs of Rods:
    I would like to see RoR going much faster than it currently does. RoR is usually limited by the CPU as it has to do a lot of floating point math to simulate the behaviour of beams and nodes. Other limiting factors probably are memory latency and bandwidth since structures for beams and nodes are quite large in size and there are hundreds of them per vehicle. Besides the fact that the whole phsyics core could use a cleanup it is also required that we increase accuracy (discussion: Discussion-Moving-to-double-precision-for-physics) to improve the quality of the simulation. When we do that a major overhaul of the physics core is needed which would be a great chance to improve performance as well. I believe that there is more room for parallelization and that we should use it whenever possible. In the best case RoR should be able to max out any number of CPU cores while still running significantly faster on a single core than it does now.

    Besides a speedup in performance I would also like to see the physics calculations being moved to the server. The details are unclear yet because it would suddenly increase server hardware requirements a lot. Maybe we will have an option to toggle serverside physics on and off.
    The major benefit of serverside physics calculation is that multiplayer collisions are possible, something that many have asked for and I want to see happening myself. It would also lead to a clear separation between client and server, potentially putting less stress on the client than before. We will have to see how much that could be since some calculations will probably still be needed clientside for movement predicition to reduce perceived lag. It would certainly seperate rendering and physics though, already increasing performance.

    I got access to an 80-core cluster computer. My ultimate goal is that the RoR server (with physics calculations being serverside) is able to take advantage of such a system. I would like to see it being able to make use of all cluster nodes using OpenMPI to spread physics calculations across all cores so we can potentially have many people spawning many vehicles in one multiplayer session. In case this becomes possible I may host a community event, hosting a RoR server on said cluster for an evening to have a big wreck fest. It's still uncertain if this is possible at all. The possible degree of parallelization for the physics core has yet to be determined. When working with clusters additional problems arise like latency and bandwidth for communication between nodes. The latency could be large enough to make this whole project fail but since a similar project probably has never been done before we can't know for certain until we tried.

    So, to summarize:
    - large performance increase
    - ability to make use of any number of CPU cores, if possible
    - serverside physics calculations
    - OpenMPI support for use on clusters

    Keep in mind though that this is just a vision of mine yet. Work hasn't even started and it will probably take a while until it does since we would like to provide a solid new stable build first. Some of these things may not even possible or won't ever come to life. We'll have to see what the future holds.
  3. 2015: Updates

    , 01-15-15 at 12:35 AM
    Man, time sure flies, Rigs of Rods is nearly 10 years old!

    I just updated some things: The-future-of-the-RoR-forums-I-don-t-know-what-to-title-this

    Updated 01-15-15 at 02:49 AM by tdev

    Official News
  4. 0.4.7 and my new foldable gooseneck trailer

    , 06-07-13 at 12:53 AM
    Just having some awesome fun with greate FPS.

    Yes it is leopard print.
  5. Best video of 2013

    , 04-12-13 at 08:46 PM

    'Nuff said.
  6. Ubuntu packages

    , 03-11-13 at 02:44 AM
  7. Step one complete, now for step two

    , 02-08-13 at 06:26 AM
    This is a follow up post to my previous one about refactoring and my plan forward.

    I have completed the first item in my list
    Way Forward (aka the plan)
    1. Replace slidenode code with outside drive-train code - Completed
    2. Refactor current wheel calculation - in progress
    3. Rewrite current drive-train to make use of new code
    4. Add new drive train features

    Here is what I wrote about the next step here:
    Refactor current wheel calculation
    Current wheels aren't very reliable, we average the speed of each node to calculate the rotation of the wheel, this is subject to fluctuation. Instead I will have one object that represents the wheel as a whole, it acts more like a traditional tire model in a game where it's simply a cylinder. This is very similar to slidenodes is that there is an ideal state, and a state the wheels actually are at.

    I'm expecting this to help solve a few issues RoR currently faces such as vehicles slipping down a slop when they should be braked. Also under this approach folding wheels should be a thing of the past.
    I am kind of gathering my thoughts on how to approach this step, and how to explain it. There are essentially two "worlds" I'll be dealing with, a beam world and a drive-train world. the beam world is the one we are familiar with, point masses held together by springs in a 3D space. The drive-train world is made of point masses held together by springs in a 1D space. So where nodes have an [x,y,z] coordinates drive-train components simply have an angle. Essentially the drive-train world is the beam world with different dimensions and units.

    So what the next step needs is translating from 1D to 3D and back. The angle in the drivetrain world will correspond to the angle offset each node is from it's original position, the hard part is how do you account for the wheel being at any odd angle? Possibly even upside down. Come to think of it, I remember now what my solution was, this is actually why I write these posts, to help me think.

    What we know is each nodes initial starting position and the current position of the axle nodes and each wheel node. If we find the rotation required to translate the axle to it's original postion we can then apply that transformation to the current wheel node position. Then use the translated current wheel node position, the center axle and the initial node position we can calculate the current angle difference from the initial position. This can then be used to calculate difference between where the node is supposed to be based on the drive-train world, and where it actually is.

    I did write a tiny program just to test this out:
    #include <iostream>
    #include <OGRE/Ogre.h>
    int main()
    	Ogre::Vector3 pn1(1, 0, 0);
    	Ogre::Vector3 pn3(1, 0, 1);
    	Ogre::Vector3 n2(0, 0, 0);
    	Ogre::Vector3 n1(0, 1, 0);
    	Ogre::Vector3 n3(-1, 1, 1);
    	Ogre::Quaternion rot;
    	 // move nodes to origin...
    	n1 -= n2;
    	n3 -= n2;
    	// get rotation
    	rot = n1.getRotationTo(pn1.normalisedCopy());
    	// move spoke to origin for rotation
    	n3 -= n1;
    	n3 = rot * n3;
    	std::cout << Ogre::Degree((pn3 - pn1).angleBetween(n3));
    	return 0;
    We'll see how logn this takes to get done. night night.
  8. Refactoring slidenodes, drivetrain, and framework

    , 01-28-13 at 11:53 PM
    Since I've been doing some coding I thought I'd share what I'm working on. First and foremost my goal right now is to rework the drive-train code, this includes the tires. But I am sort of taking a round about approach to this which includes some pretty heavy refactoring. I've written a lot of concept code in the past for a new drive-train but never put it to use. I also wrote it in a reusable manner and am expanding this design.

    The drive-train code I did write works on it's own, it just needed to be integrated into RoR. The new drive train code is built on the same principle as RoR, nodes and beams. Instead of nodes and beam in a 3 dimensional space we have nodes and beams in a 1 dimensional space. replace position with angle, velocity with moment, and force with torque and you have the same equations. This is where I started.

    So I am basically building a parallel "world" for the drive train that works similar to nodes and beams. My starting point was going to be the wheels, since they essentially act like the gate way between the node/beam world and the drive-train world. My approach here is to simulate a drive-train wheel object which is nothing more than an an angle, then calculate where the nodes should be positioned based on that angle. While I was working on this, I realized that this is drive-train same concept I'm using for slide nodes: calculate where a node should be, calculate beam-like forces from where the node is, and where the node should be and distribute forces appropriately. So I started hacking away at some concept that I could use for both when I dawned on me that I had already written this code a long time ago for the drive train.

    So here is a bit about my theory behind the drive-train code, and what will most likely be used in many many more places than the drive-train. As I've worked in the BeamForcesEuler routine I've realized that it boils down to two actions, updating the forces that act on a node, and updating the nodes position. I call them sources, and sinks; sources generate/calculate the forces based on the environment and are applied to the sinks, the sinks take the forces and decide what to do with them. In RoR terms sources are beams, engine, wings, commands, collisions, etc, etc, and sinks are nodes.

    One of the cool ideas I will be able to introduce with this new idea is per-node integrators, I feel this will be handy because some weight/spring combinations are not stable but would be if a different integration method is used.

    Way Forward (aka the plan)
    1. Replace slidenode code with outside drive-train code
    2. Refactor current wheel calculation
    3. Rewrite current drive-train to make use of new code
    4. Add new drive train features

    Replace slidenode code with outside drive-train code
    I'm doing this first because it's an existing system so I will be able to just test out the new code against existing slide node behavior to tell if it is working. This will be the biggest change all other items will make use of the concepts implemented here.

    Refactoring this code will also have the added benefit of slide node damping since it's already built into the code I will be integrating.

    Refactor current wheel calculation
    Current wheels aren't very reliable, we average the speed of each node to calculate the rotation of the wheel, this is subject to fluctuation. Instead I will have one object that represents the wheel as a whole, it acts more like a traditional tire model in a game where it's simply a cylinder. This is very similar to slidenodes is that there is an ideal state, and a state the wheels actually are at.

    I'm expecting this to help solve a few issues RoR currently faces such as vehicles slipping down a slop when they should be braked. Also under this approach folding wheels should be a thing of the past.

    Rewrite current drive-train to make use of new code
    Make sure the current drive train code works and behaves as is with the new wheel model, and make use of new code to perform drive train calculations. The current code is a bit of a mess and there is a bug where the first two axles are locked together but none others, this should solve that problem.

    Add new drive train features
    Multiple engines, torque converters, clutches, lockers, limited slip, multiple gear boxes, transfer-case, brakes, etc

    My goal here is to model any and all kinds of different power, be it a traditional engine and 4 wheels, a parallel hybrid with two different engine types, or a helicopter with one engine powering two different rotors. Or who knows what. I want to flip over a car, spin one wheel with the mouse and watch the other wheel spin in the opposite direction when using an open diff. the best part IMO is that I've already got some of this working. I've test locked, open, and LS diffs. I've tested with one power source, and I've tested with two power sources.

    And Beyond!
    I plan on using this framework throughout RoR, hoping to achieve better performance, multiprocessor support, more organized, and easier to alter.

    I'm excited

    My work and progress is viewable here:
    What I will be using for much of my refactoring is here:
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