rendering by Ogre

[charlieg]

Gave you a mention on the blog:
http://freegamer.blogspot.com/2010/08/two-weeks.html

Some positive responses already. Looks like you've had a few downloads.

[CrystalH]

It feels proud to be mentioned near VDrift My project is so small, that it would be even hard to compare.
But with popularity came issues and they will probably slow down the progress a bit.

[Thib25]

I saw this video on youtube and i think that's you did a very good job with Ogre3d.
http://www.youtube.com/watch?v=WGksziaPr-4

Like someone said in comment on this link :
http://freegamer.blogspot.com/2010/08/two-weeks.html

It would be a very nice Colin Mcrae Rally clone.

Have you ever thought of making it a rally game? It will be a very great idea, and if you accept, I can help you with cars and, maybe, tracks because I am currently working on cars for the game Richard Burns Rally.

PS : excuse me if my english is not correct because I am french. I hope you understand me .

[joevenzon]

An open-source rally simulation would be *awesome*!

VDrift has one rally track converted from TORCS but overall could use more rally stuff. :-)

[CrystalH]

Thanks Joe, I'm glad you like it.
Thats what I intend it to be, a rally with stunt elements. Only with closed tracks because of memory consumption and terrain/paged trees implementation, I also think it's more fun this way.

I've done some loops, different styles, and with banks. This makes them easier to drive through, you dont fall off, just bounce few times (unless driving to slow). I had to harden the suspension to drive them.
Here are some pictures:
http://picasaweb.google.com/CryHam/StuntRallyVer4#
This will definitely be in next release.

As for the CMR clone, I dont want to clone anything. I hope this will be an original game by itself, even if a bit similar to Stunts (1990), Generally, RBR or any other great game (or a mixture of them).
I surely want to create a track editor, but it's still a long way. And lastly, I don't care about HDR, bloom, blur and all that stuff, I want it to be playable (with good fps) and fun.

[Thib25]

When I say "CMR clone", it's just to illustrate :wink: . I don't care HDR, bloom and blur too. I think your version like it's now is great but I just dream to have a game with high-detailed cars and tracks like RSRBR mod for RBR or GTR Evolution.

[CrystalH]

Well, in my opinion, a car in a game is only this good as it's simulation, no matter how good it looks (how many triangles or shader operations per pixel it has). That's because I'm a programmer: I check this->first; if you're an artist look is more important.

But I wouldn't mind seeing an EVO or Impreza or other car in VDrift (would be also available in StuntRally) if it's self made or free.
On the other hand, I would feel better if we had some more free trees/plants/grass. There are 2 trees, 2 ferns and 1 grass texture here on 3 terrains. It's too few for jungle and not fit for desert, not mentioning winter.
Anyway any help in developing is welcome.

[CrystalH]

Hi and greetings again.
Just posting to say I've uploaded next release version 5. Didn't change anything in simulation though, only fixed few graphical issues.

The project and downloads are still there:
http://code.google.com/p/vdrift-ogre/
and also there is a new video from the loops track (which looks better now):
http://www.youtube.com/user/TheCrystalHammer

[CrystalH]

Hi, just made another release (version 6).
It has few new tracks, and a Track editor. I've wanted it since the beginning, to edit terrain, road and then to drive on it. It's an early version so many features are still missing but basic terrain tools and complete road editing are done.
After save, the modified track can be driven in game.
It probably needs time to get used to, and has no undo, but for me it's quite easy and fast to operate with.

[CrystalH]

Just made new feature on tracks, namely pipe roads, they are in version 7 now, made a video of it too. The link to project page is still the same (and it has links to screenshots and videos):
http://code.google.com/p/vdrift-ogre/

I had to increase suspension's spring-constant from 60000 to 160000, the suspension is very stiff now and never reaches end of travel. But it was required for pipes.

I have tested it on those circle tracks with half/full pipe. Now you can drive 300 kmh easily without suspension bumps. Before, already with 160 kmh suspension was unstable making bumps on very even road (when reaching end of its travel, caused by car's centrifugal acceleration from circle track). This was probably also present in loops, but they have smaller radius so it's not that noticeable.

I'm using bullet trimesh for those pipes, it has to be quite dense for smooth drive. Can beziers be used for pipes ? Don't know if it's worth it because bullet trimesh is still needed for chassis collision.
I still hope it's okay to post here (?), no replies for some time.

[NaN]

Can beziers be used for pipes ?

Your pipes are generated from spline curves? Then I think it should be possible to write a ray cast function for them for a given tube radius.

no replies for some time.

This probably means people are busy with their own stuff. Public interest into open source racing games is rather low due to the abundance of very well made commercial alternatives imho. And VDrift is nowhere near to even think about competing with them. It is more of a "do it for your own pleasure" activity. You might consider bumping Charlie(charlieg) to get some coverage/feedback on his blog. Keep posting.

[CrystalH]

Pipes come from the same spline as whole road, but I guess there may be some trouble with transitions to flat road (begin or end of pipe). I thought of using beziers because they are already in VDrift, I also thought of casting a cylinder instead of ray, but I guess it would hit performance too much. But for now I will probably leave it as it is.

I do it for pleasure (and share it so others can have it too), especially creating tracks is a feature I missed a lot in all commercial games. The spline road and its editing in 3D is something I like most here, it may be less simple but gives the possibility of creating any road also in air.

[NaN]

In VDrift the intersection point with the bezier is calculated by adaptive tessellation of the bezier patch(refining ray-quadrilateral intersection). I have been playing with the idea to adapt this technique to track meshes. Retrieve the intersecting triangle from bullet, use vertices and normals of the triangle as patch parameters, raycast against it.

[CrystalH]

Just released new version 1.0. It features 7 drivable cars with a very fast XM.
There is a new video of 6 minutes gameplay:
http://www.youtube.com/user/TheCrystalHammer

Mainly I have extended the Track Editor, so it has everything needed to create and edit tracks in it, including surface parameters.
It looks to me like RollResistanceCoefficient is not used and FrictionTread also. Anyway I was thinking of changing some of Pacejka's coefficients (a0-a3 or more) for tires on different surfaces, to change the surface's feeling more. But does that sound realistic ? And probably not easy to figure out the range so it works for all cars in the same way.

[NaN]

What revision are you using?

Rolling resistance is disabled until reimplemented properly(need a friction constraint for wheels).

The friction coefficient for the tires:

Code:

btScalar friction_coeff = tire.GetTread() * surface.frictionTread + (1.0 - tire.GetTread()) * surface.frictionNonTread;

There is also surface drag(velocity is linear velocity of the wheel):

Code:

velocity * surface.rollingDrag * 0.25;