Racer v0.8.23 released!

[Ruud]

An important one.
Troubles expected with this one:
- linearity of the steering wheel (you for one now need to specify the wheel lock in the setup screen before starting to judge things)
- a new parameter ('sunny') in most fragment shaders (any typos?). For a simple 'overcast' type of thing where you allow less sun to shine through.
- dbg_car.flip_tan=1. Perhaps a major breakthrough on the physics end. Where I always used a tan(SA), it might have needed to be atan(SA). Ouch, we're going to test this on our high-end sims later today, see how it feels (easier to do than with a G27).
- steering controls are now in degrees, rather than normalized. How about center_squeeze (and related) for Mz reduction near 0? Haven't looked at that yet.

The download: http://www.racer.nl/download/racer0.8.23.zip (67Mb)
Then get the latest exe flip_tan bugfix (only exe): http://www.racer.nl/download/racer0.8.23b.zip
(5Mb)
*after some testing, it appears than dbg_car.flip_tan should be 0* (the older situation)

The changes:
- Steering revised quite a bit - the controls for steering left/right now use degrees, instead of being
normalized. This changed some things inside the physics engine to use rotation more directly.
The idea: set your controller's lock correctly. With cars that have a steering lock that is smaller
or equal to that of the controller lock, the steering is direct (1:1). If a car has more lock defined
in its car.ini, linearity will be applied on the controller's steering output (now in degrees) to let it
use the full range of the car's steering wheel (linearity=controllerLock/steerLock).
This all targeted a bit for 900 degrees where you no longer then have to tweak for a lot of cars.
The controller setup screen is being worked on to visually check the lock (press F5 twice in the setup
screen to show the 'Wheel' page).
- Controller lock is now saved in the setup screen.
- A new important physics tweak is available: dbg_car.flip_tan. Defaulting to 0 (the v0.8.22 behavior),
setting it to 1 modifies the slipangle calculations for each wheel to use atan() rather than tan().
The tan() has been in there for a long time, to stabilize high slipangles. But, tan() makes values
worse as they grow, instead of flattening them like atan(). So, this needs to be investigated;
probably it has quite an influence on slipping behavior (with big slipangles).
- bloom_shadows_f.cg accidentally had bloom turned off
- Flare Cg shaders tweaked for nicer looks (alpha changes)
- log file position group added 'lap' (ASCII format)
- Added motion_blur.stencil option - use 1 for the old projected shadows, 0 for shadowmapping (faster)
- Added dev.nvidia_perf option that will try to access nVidia PerfSDK counters if installed.
Install an instrumented driver for this to work.
- Added a profile debug page (Ctrl-6, may have to press twice for the 2nd page) to see some nVidia performance counters.
I must say it bluescreened my XP machine more than once, so be careful with instrumented drivers.
- Added envmap.live_track.frames_per_update for more live track mapping control
- Fixed some tough render engine bugs that messed up Z-buffer usage (mirror on made the screen flicker)
- Generic models weren't transforming; fixed.
- Added wiper modes (off/interval/normal/fast), use 'w' to switch to the next mode (see also Ctrl-4 for the current mode)
- dyn_standard_bump_reflect_f.cg now also lets bumpmap alpha affect specular (next to reflectiveness)
- Sky_f.cg and sky_daynight_f.cg modified so clouds=1 now gives the normal effect (and does not raise
cloud regions to 175 klux!)
- A track's exposure in special.ini is now correctly used as the initial exposure (no more starting
with white, then coming back to a normal exposure if you set this one to a nice value; like 0.02?)
- Fixed a bug in the fresnel calculation in dyn_standard_bump_reflect_v.cg, which gave bad looking
reflections.
- Selecting Bloom/Shadowmapping from the menu gave problems with undefined 'gammaFactor' errors.
- Surround Gaming mode camera aspect fix (director mode)
- A surface's 'grip_decline_driveline' now defaults to 0 (was 1). Fixed issues with grip declining by default.
- Panorama shader's extinction now uses 'scale' Cg parameter instead of hardcoded value (5). Add 'scale' to
your track.shd file.
- Backfire would sometimes not work. This and a bunch of other uninitialized data fixed.
- 2D elements in the render engine could mess with motion blur blending (OpenGL state cache).
- When bloom was on, the aliased buffer was anti-aliased twice! (for bloom and at postprocessing)
- blur_alpha didn't work; the fullscreen shaders didn't output correct alpha. Using a bit of blur_alpha now
by default (0.3).
- Auto exposure sampling did an anti-alias pass; now it uses a previously anti-aliased result (faster).
- Dropped config.exe for now - anybody using it actively? Most should be settable ingame.
- Added 'sunny' in special.ini (tracks); 0=totally overcast, 1=super sunny. For ground objects.
Needs to be added to all fragment objects though. Also adds script cmd 'sunny <x>' to set it live.

 

[Mr Whippy]

I agree with you both.

Not to always reference GT5, like it seems I might, but in there you have a quick little tyre temp readout, and if you do a quick acceleration the smoke is low, but if you let the tyres spin for a second hard, then the readouts go red and they just pour smoke off.

This would make sense for braking where right now we can get ABS working, with smoking coming off the front tyres now and again, and would only allow smoke for full on lock ups.

It would also be nice for accelerating away and having it take time to get real smoke pouring off the tyres. I guess this can't be hard to program in?


Also noticed the smoke blowing away too sometimes. Great if it's windy, but I think it's a bug.


I think just those tweaks as per Alex mentioned would make smoke look much more natural, and in theory it's a fairly simple little bit of code, for now at least

Dave

 

[DavidI]

Also noticed the smoke blowing away too sometimes. Great if it's windy, but I think it's a bug.

It doesn't look like its 'blowing away' though, its more like it accelerates off into the distance, something with it doesn't look quite right. I'd like some form of wind direction & force type variables to feed into Cg, so my clouds can move in the same direction and speed roughly as my tree's get blown in. Ultimately I'd like Racer to generate some sort of varying wind force, but for now I'd be happy with a constant set in special.ini. Maybe it could be linked with clouds (& sunny; erm what IS the go with that, isn't sunny just an inverse of cloud?) so the more cloud, the strong the wind is scaled? I know that isn't quite realistic, but it'd do for now.

 

[Ruud]

Okay, that makes sense then Guess it's time to stop being lazy and update all my tracks for cg.

Racer v0.8.24 has an updated non-Cg version. Runs around 600fps here, with Cg, v0824 runs 185fps. Not too bad considering it's doing a lot more.

 

[Ruud]

I don't know if anyone else has noticed, but skidmarks only work when sliding sideways.

I've mentioned that the tiresmoke should ideally be hooked to some sort of tire heating calc. such as SA*time=smoke amount. I think that the amount of smoke generated should be fairly consistent with the heating mainly affecting the alpha.

I'll check the skidmarks out for v0825. As for the smoke amt, that might need some tuning indeed. Although in Gt5 they just set the time to 0.5s and be done with it.

 

[Alex Forbin]

I'll check the skidmarks out for v0825. As for the smoke amt, that might need some tuning indeed. Although in Gt5 they just set the time to 0.5s and be done with it.

Thanks for the reply. If you have GTA4 it has really nice smoke that appears to be directly controlled by tire heating. The main thing that distracts me about the present smoke is that it seems to just pop into existence, at low speed it's not noticeable but at high speed it looks a bit odd. I'm not sure of the best way to eliminate this.


Alex Forbin

 

[Mr Whippy]

I'll check the skidmarks out for v0825. As for the smoke amt, that might need some tuning indeed. Although in Gt5 they just set the time to 0.5s and be done with it.

We could also hopefully tie the intensity of the skid mark with the intensity of the smoke... so that only a full-on burnout will put really dark marks down...

GT5 does seem to do a generic heating/cooling cycle most of the time. I've not really experimented much but it's hard to tell without any debug info to look at slip ratios etc...
Racer can do it better anyway... I guess a system a little like the brake heating/cooling could work for tyres?! (don't want to add un-needed tasks to your list of course, just pondering how you might do it )

Dave

 

[Alex Forbin]

We could also hopefully tie the intensity of the skid mark with the intensity of the smoke... so that only a full-on burnout will put really dark marks down...

GT5 does seem to do a generic heating/cooling cycle most of the time. I've not really experimented much but it's hard to tell without any debug info to look at slip ratios etc...
Racer can do it better anyway... I guess a system a little like the brake heating/cooling could work for tyres?! (don't want to add un-needed tasks to your list of course, just pondering how you might do it )

Dave

Yeah, we had nice fading in/out skids for a while. I think you're right on using the same basic system as the brakes, it varies a little in that heating can occur laterally as well as long., but I wouldn't think there would be a great difference.
The more I think about it, the more it seems that the number of particles should stay roughly the same since this determines the smoothness of the appearance of the smoke, and that the alpha/size/speed should vary according to tire heating.

Here are a few observations about tire smoke (feel free to add).
1. It is very viscous, air is like a fluid and has mass/viscosity/inertia just like any fluid.
2. It has a tendency to cling to the car somewhat.
3. The basic transparency (alpha) seems to be a direct function of tire heating and velocity.
4. There should be some way of blocking it from inside the cabin, I realize it does enter the cabin IRL but currently it just floats by as if nothing is there.
5. It goes down and bounces off the ground in front and up into the body or air (open wheel) in the back.

I realize that all we are really after is a good looking approximation and not a CFD (computationally fluid dynamics) simulation, but the better our grasp of realism the better we can fake it.

Alex Forbin

 

[camsinny]

Could use newton's new hull mesh to determine where smoke is allowed?

 

[Alex Forbin]

Could use newton's new hull mesh to determine where smoke is allowed?

That seems logical, all cars should have it anyway.

Alex Forbin