Racer v0.8.26 released!

[Ruud]

The usual, but 2 big things: a garage when selecting the car (getting rid of the white cars) and an important bugfix if the CG is not at the nullpoint.

Get it at http://www.racer.nl/download/racer0.8.26.zip (100Mb, due to the extra garage track!)
CG movement patch (only the racer.exe) is at http://www.racer.nl/download/racer0826b.zip (1.5Mb).

The garage is still a rough preview but you can plugin your own garage1 track (I might add the possibility of multiple garages). The CG bugfix is optional; in racer.ini find 'move_cg': 1 is the new default, 0 is the situation as from v0.8.25.

Changes:
v0.8.26 (10-12-10)
-----------------
- Skidmarks tweaked to be more opaque.
- Some bumpshaders modified the normal map's alpha, giving funny reflectiveness issues.
Resolved using an extra 'common/utils.cg' file with UnpackNormal() and used in all bump shaders.
- Best line tweaked; fades out near the car, green lines are faded. Less intrusive.
- Added Logitech G25 wheel preset file (thanks to QuadCoreMax)
- Modeler can now export a template shader (.shd) file for a loaded model
- Pressing P in replay a few times doesn't mess up the volume (on/off) anymore
- Non-Cg version still created mirror and live track FBO's
- Particle system would crash with some car/track combinations. Seems related to culled single-poly fences.
The road is culled and single-poly, and really hitting the track seems a problem for Newton.
- Same change for the particle system done to the exhausts (arrays instead of std:vector)
- Not all collide polygons were used for Newton's collision tree. Rebuild trackcollision.bin
- Car selection screen now loads 'garage1' track as the environment. Pitpos0 is the car location.
- Tracked spline selection now accepts Shift-[,] for multi-select (local grip editing)
- Default font made a bit smaller, since everyone's running at least 1024x768 anyway.
- The Ctrl-9 screen could show bad load balance when the nullpoint was outside
of the front and rear wheel susp<n> locations (extreme CG movement tests).
- CG translation bugfix in the physics; an important one! Use move_cg=1 in racer.ini.
- Ghost car playback didn't work correctly.

 

[DavidI]

I still see an issue with cars & wheels. if I start racer on mugello with lambo, no brakes on, the car rolls backwards with the slight incline there, front wheels rotate rearwards like they should, rear wheels rotate forwards slowly. Different combinations of cars on different tracks all yield the same results. Cars with full brakes on slowly creep down inclines, and driven wheels without brakes on appear to be able to rotate independantly of the surface they are contacting.
Do all cars have a pacejka issue, or does racer have an issue, or both?

 

[Ruud]

@Boomer: those washed out mirrors. I noticed that on the SL65AMG as well. I modified the shader's (shader_mirrors I think) to add 'diffuse=0.1 0.1 0.1' and that helped. Not sure though why it needs 10% diffuse-ness to become nicely visible.
See the attached image.

 

[Ruud]

I still see an issue with cars & wheels. if I start racer on mugello with lambo, no brakes on, the car rolls backwards with the slight incline there, front wheels rotate rearwards like they should, rear wheels rotate forwards slowly. Different combinations of cars on different tracks all yield the same results. Cars with full brakes on slowly creep down inclines, and driven wheels without brakes on appear to be able to rotate independantly of the surface they are contacting.
Do all cars have a pacejka issue, or does racer have an issue, or both?

Transient Pacejka (not pure Pacejka), the 'standing still on a hill' issue. I might have a look; ever noticed for example the 'grip 0.1' also tends to do some overcorrection to the engine torque? Probably not the engine torque, but something in the wheels perhaps. Hm.

For transient Pacejka, as you stand still and have SA=SR=0, you get 0 force. It then starts to move (gravity), it gets a non-zero SA and/or SR -> forces. Then it goes to standstill, again 0 force etc. At 1000Hz this is visible...

 

[DavidI]

The old 'standing still on a hill pacejka issue'...

I have noticed with Gravedigger at low speeds on inclines doesn't always react how I'd expect. That could be GD specific pacejka related I guess too.

My big issue with GD is I still can't use real life weights & values, as the generated forces easily surpass the racer.ini caps.
Do I have to do a fudge & try reducing everything by ~1/4?

GD's ~4 tonne rolling, so I figure 4x reduction should get it in the realm of a 1 tonne car, but I can see a lot of fudges & compromises there. Not that I have any hard real figures anyway, & I doubt GD has razor sharp handling IRL, but I'd like it to be as close to real as I can. Any idea's & input would be appreciated.

 

[Mr Whippy]

You guys ever driven slowly in GT5, the weird movements are about 2-3 times worse... ie, very low speeds turning up a banked bend and the back end moves sideways about 4x as fast as it's moving forwards, but there is no 'slip' occuring for this to happen.

As Ruud said I guess this is the very low speed things flickering around 0 issue. You could probably damp it out but then you might get new odd behaviours like stickiness before setting off?!


To be honest once you are going about 0.75m/s or more, all these issues disappear... so I'm fairly relaxed. It's called Racer, not Stationary'er

Dave

 

[DavidI]

You guys ever driven slowly in GT5

I can never get past the impulse to just floor it & go balls out. R U nuts?
Standing still on a racetrack & having front & rear wheels rotating in opposite directions looks a tad strange & i'd verge towards being a bug

 

[Ruud]

The twitch at 0 speed has to do with the diff. At wheel velocity reversal it sets some SA/SR etc variables to 0. Trying to improve things. There's also a test with braking torque I like to do; a magical trick of setting brakeTorque*=-tanh(spinVelocity), which reduces braking torque as the wheel starts to stand still. (somebody here is working on Simulink physics models, too slow for general Racer use)

 

[Mr Whippy]

Hmmm, if you reduce braking torque as the wheel starts to stand still, is that world relative, it doesn't look like it.

Not much use if you want to brake and lock up the wheels?!

Hmmm

Dave

 

[Ruud]

It's body relative. It works ok-ish, even if you think the locking up will make braking go away. Still, it seemed a bit better by just letting the brake torque go. Also, the wheel velocity reversal resetting SR variables removed took care of the wheel funny motion.
v0.8.27 out in less than 30 minutes.

 

[Alex Forbin]

It's body relative. It works ok-ish, even if you think the locking up will make braking go away. Still, it seemed a bit better by just letting the brake torque go. Also, the wheel velocity reversal resetting SR variables removed took care of the wheel funny motion.
v0.8.27 out in less than 30 minutes.

Great news. I had never mentioned it before since it seemed so trivial, but the slowly spinning wheels have always bugged me.

Any idea yet why the bounding boxes are not working? Sorry the BOXES work fine, it's the convex hulls that are broken.

Alex Forbin

 

[Ruud]

Which car gives trouble with the hull? If I check the Lambo's hull with 'wireframephys on', it looks ok...

 

[Alex Forbin]

Which car gives trouble with the hull? If I check the Lambo's hull with 'wireframephys on', it looks ok...

Actually any hull, the lambo does it too.
Sometimes it appears that it is going to work then the roof "collapses".



Alex Forbin

 

[Ruud]

Indeed, I'm sorry, the hull was too far optimized. Turned out that Newton accepts a tolerance, and that was set too high; so it started optimizing a lot out. I made that tolerance a lot lower and now it looks ok again... (for v0.8.28)

 

[Alex Forbin]

Thanks

Alex Forbin