Slippery/bumpy surfaces

[thelusiv]

Varying degrees of friction are now possible in VDrift again. Last night Joe set up some new features of the track listedit tool which sets the properties of objects on the track. He also added some bumpiness settings. Road Atlanta is the only track which has been updated to work with these new features, so none of the other tracks will load! This is all in the latest SVN so if you want to test it out go ahead, let us know what you think. We'll work to get the tracks updated so they all work again very soon.

[thelusiv]

Varying degrees of friction are now possible in VDrift again. Last night Joe set up some new features of the track listedit tool which sets the properties of objects on the track. He also added some bumpiness settings. Road Atlanta is the only track which has been updated to work with these new features, so none of the other tracks will load! This is all in the latest SVN so if you want to test it out go ahead, let us know what you think. We'll work to get the tracks updated so they all work again very soon.

[alex25]

Varying degrees of friction are now possible in VDrift again. Last night Joe set up some new features of the track listedit tool which sets the properties of objects on the track. He also added some bumpiness settings. Road Atlanta is the only track which has been updated to work with these new features, so none of the other tracks will load! This is all in the latest SVN so if you want to test it out go ahead, let us know what you think. We'll work to get the tracks updated so they all work again very soon.

i'll try to fix the tracks i converted. do these numbers have some equivalent in racer, or do we just have to come up with them? thanks.

--alex--

[alex25]

Varying degrees of friction are now possible in VDrift again. Last night Joe set up some new features of the track listedit tool which sets the properties of objects on the track. He also added some bumpiness settings. Road Atlanta is the only track which has been updated to work with these new features, so none of the other tracks will load! This is all in the latest SVN so if you want to test it out go ahead, let us know what you think. We'll work to get the tracks updated so they all work again very soon.

i'll try to fix the tracks i converted. do these numbers have some equivalent in racer, or do we just have to come up with them? thanks.

--alex--

[clytle374]

Sweet

[clytle374]

Sweet

[thelusiv]

The features were added to the listedit tool but you'll have to go through the code now to see how it works...Joe told me a little about it last night, here's the stuff about friction:

(22:56:48) Venzon: i had to change the object list.txt file format
(22:56:54) Venzon: but converting to the new format isn't too hard
(22:57:05) Venzon: you could even write a script to do it pretty easily
(22:57:26) Venzon: here's how:
(22:57:33) Venzon: open up the list.txt file in a text editor
(22:57:39) Venzon: add 10 to the top of the file
(22:57:45) Venzon: like, the number 10... on its own line
(22:57:56) Venzon: then start up listedit and load the list.txt file
(22:58:04) Venzon: do the following commands:
(22:58:10) Venzon: addparam 1.0
(22:58:12) Venzon: addparam 0.9
(22:58:45) Venzon: that adds the new parameters to the track files. the first one is the friction coefficient for non-treaded (road racing) tires
(22:58:59) Venzon: the second one is the friction coefficient for treaded (rally/off-road) tires
(22:59:23) Venzon: by doing addparam you create a 10 and 11 that you can use with set
(22:59:45) Venzon: and addparam also automatically sets the defaults
(22:59:48) Venzon: then you can save that
(22:59:52) Venzon: and exit listedit
(22:59:57) Venzon: and then oooone more thing
(23:01:11) Venzon: add the following to the track.txt file:
(23:01:14) Venzon: non-treaded friction coefficient = 1.0
(23:01:14) Venzon: treaded friction coefficient = 0.9
(23:01:26) Venzon: that's the default friction for the smooth road surfaces
(23:01:29) Venzon: and then you're done
(23:01:35) Venzon: wow, that sounded like a crazy long number of steps
(23:01:43) Venzon: it seemed simpler in my head :-)
(23:03:21) Venzon: also set 7 (used to be reserved) is now bumpiness

car tire tread stuff:

(01:11:43) Venzon: the [tires-front] and [tires-rear] sections in the .car file contain a new "tread" parameter that defines how much tread is on the tire
(01:11:57) Venzon: G4 has 0.0, TC has something higher, like 0.7...
(01:12:16) Venzon: i have the surfaces set up on road atlanta so that a tire with 1.0 tread has a 0.9 friction coefficient
(01:12:25) Venzon: and 0.0 tread has a 1.0 friction coefficient
(01:12:28) Venzon: on asphalt
(01:12:54) Venzon: off-road, it's 0.7 for no tread, 1.0 for full tread
(01:12:59) Venzon: not totally realistic
(01:13:14) Venzon: but should be in the ball park once bump is in there

and the stuff about bumpiness:

(01:28:58) Venzon: the bumps in the off-road parts are set at 2 meter wavelength with 0.03 meter magnitude
(01:29:15) Venzon: all of the bumpiness and friction stuff can be set per object as they are now parameters in the list.txt file
(01:29:23) Venzon: check the updated format.txt in the listedit folder in the track editor
(01:29:32) Venzon: it probably needs some work
(01:29:37) Venzon: the TC is way too grippy off-road
(01:29:41) Venzon: and probably other cars, too
(01:30:05) Venzon: it's fun to drive the TC around the edges of road atlanta in the cockpit view, though
(01:30:08) Venzon: nice and bumpy
(01:42:20) Venzon: wow, the SB comes alive on the bumps... weird

[thelusiv]

The features were added to the listedit tool but you'll have to go through the code now to see how it works...Joe told me a little about it last night, here's the stuff about friction:

(22:56:48) Venzon: i had to change the object list.txt file format
(22:56:54) Venzon: but converting to the new format isn't too hard
(22:57:05) Venzon: you could even write a script to do it pretty easily
(22:57:26) Venzon: here's how:
(22:57:33) Venzon: open up the list.txt file in a text editor
(22:57:39) Venzon: add 10 to the top of the file
(22:57:45) Venzon: like, the number 10... on its own line
(22:57:56) Venzon: then start up listedit and load the list.txt file
(22:58:04) Venzon: do the following commands:
(22:58:10) Venzon: addparam 1.0
(22:58:12) Venzon: addparam 0.9
(22:58:45) Venzon: that adds the new parameters to the track files. the first one is the friction coefficient for non-treaded (road racing) tires
(22:58:59) Venzon: the second one is the friction coefficient for treaded (rally/off-road) tires
(22:59:23) Venzon: by doing addparam you create a 10 and 11 that you can use with set
(22:59:45) Venzon: and addparam also automatically sets the defaults
(22:59:48) Venzon: then you can save that
(22:59:52) Venzon: and exit listedit
(22:59:57) Venzon: and then oooone more thing
(23:01:11) Venzon: add the following to the track.txt file:
(23:01:14) Venzon: non-treaded friction coefficient = 1.0
(23:01:14) Venzon: treaded friction coefficient = 0.9
(23:01:26) Venzon: that's the default friction for the smooth road surfaces
(23:01:29) Venzon: and then you're done
(23:01:35) Venzon: wow, that sounded like a crazy long number of steps
(23:01:43) Venzon: it seemed simpler in my head :-)
(23:03:21) Venzon: also set 7 (used to be reserved) is now bumpiness

car tire tread stuff:

(01:11:43) Venzon: the [tires-front] and [tires-rear] sections in the .car file contain a new "tread" parameter that defines how much tread is on the tire
(01:11:57) Venzon: G4 has 0.0, TC has something higher, like 0.7...
(01:12:16) Venzon: i have the surfaces set up on road atlanta so that a tire with 1.0 tread has a 0.9 friction coefficient
(01:12:25) Venzon: and 0.0 tread has a 1.0 friction coefficient
(01:12:28) Venzon: on asphalt
(01:12:54) Venzon: off-road, it's 0.7 for no tread, 1.0 for full tread
(01:12:59) Venzon: not totally realistic
(01:13:14) Venzon: but should be in the ball park once bump is in there

and the stuff about bumpiness:

(01:28:58) Venzon: the bumps in the off-road parts are set at 2 meter wavelength with 0.03 meter magnitude
(01:29:15) Venzon: all of the bumpiness and friction stuff can be set per object as they are now parameters in the list.txt file
(01:29:23) Venzon: check the updated format.txt in the listedit folder in the track editor
(01:29:32) Venzon: it probably needs some work
(01:29:37) Venzon: the TC is way too grippy off-road
(01:29:41) Venzon: and probably other cars, too
(01:30:05) Venzon: it's fun to drive the TC around the edges of road atlanta in the cockpit view, though
(01:30:08) Venzon: nice and bumpy
(01:42:20) Venzon: wow, the SB comes alive on the bumps... weird

[alex25]

(22:58:10) Venzon: addparam 1.0
(22:58:12) Venzon: addparam 0.9
(22:58:45) Venzon: that adds the new parameters to the track files. the first one is the friction coefficient for non-treaded (road racing) tires
(22:58:59) Venzon: the second one is the friction coefficient for treaded (rally/off-road) tires

quick question (before i start updating my tracks). the above would seem to imply that the first coefficient is for non-treaded tires while the second is for treaded ones (backed up by listedit/format.txt). but if i look at road_atlanta/objects/list.txt the coeffcients seem to be in reverse order:

Code:

raroad1.dof-01.joe
grasa.bmp.png
1
0
0
0
2.0
0.03
1
0
0.7
1.0

does that mean road_atlanta is wrong?

also, i guess the coefficients should be different for grass (small) road (i guess around 1) and a gravel pit (10 or so). can the coefficient be greater than 1?

--alex--

[alex25]

(22:58:10) Venzon: addparam 1.0
(22:58:12) Venzon: addparam 0.9
(22:58:45) Venzon: that adds the new parameters to the track files. the first one is the friction coefficient for non-treaded (road racing) tires
(22:58:59) Venzon: the second one is the friction coefficient for treaded (rally/off-road) tires

quick question (before i start updating my tracks). the above would seem to imply that the first coefficient is for non-treaded tires while the second is for treaded ones (backed up by listedit/format.txt). but if i look at road_atlanta/objects/list.txt the coeffcients seem to be in reverse order:

Code:

raroad1.dof-01.joe
grasa.bmp.png
1
0
0
0
2.0
0.03
1
0
0.7
1.0

does that mean road_atlanta is wrong?

also, i guess the coefficients should be different for grass (small) road (i guess around 1) and a gravel pit (10 or so). can the coefficient be greater than 1?

--alex--

[joevenzon]

Road atlanta is correct. If you'll notice, you're looking at a grassy object, so the friction for non-treaded is 0.7 and treaded is 1.0. These are the values for grass from vamos. I'm not sure what values they had for racer. 0.7 may be too high.

To be clear, here's what I did after the addparam commands on road_atlanta (still in the listedit tool):

Code:

set 0 * 10 0.7
set 0 * 11 1.0
set 1 road* 10 1.0
set 1 road* 11 0.9

The first two lines set every single object to have grass-y friction numbers. The second two lines set all objects with texture names of road* (which, for this particular track, happen to be all of the pavement type surfaces) to have asphalt-y friction numbers. The way this works in the code is that every tire's friction numbers, which are computed each physics frame, end up getting multiplied by a friction coefficient. The friction coefficient is determined by:

Code:

surface_friction_coefficient = (1.0 - tread)*non_treaded_friction + tread*treaded_friction

where "tread" is the tread parameter for the tire as defined in the .car file.

Don't set any friction values larger than 1.0. It's possible to do, but don't -- if you're doing this, then you don't understand how it works because it's not really what you want to do.

[joevenzon]

Road atlanta is correct. If you'll notice, you're looking at a grassy object, so the friction for non-treaded is 0.7 and treaded is 1.0. These are the values for grass from vamos. I'm not sure what values they had for racer. 0.7 may be too high.

To be clear, here's what I did after the addparam commands on road_atlanta (still in the listedit tool):

Code:

set 0 * 10 0.7
set 0 * 11 1.0
set 1 road* 10 1.0
set 1 road* 11 0.9

The first two lines set every single object to have grass-y friction numbers. The second two lines set all objects with texture names of road* (which, for this particular track, happen to be all of the pavement type surfaces) to have asphalt-y friction numbers. The way this works in the code is that every tire's friction numbers, which are computed each physics frame, end up getting multiplied by a friction coefficient. The friction coefficient is determined by:

Code:

surface_friction_coefficient = (1.0 - tread)*non_treaded_friction + tread*treaded_friction

where "tread" is the tread parameter for the tire as defined in the .car file.

Don't set any friction values larger than 1.0. It's possible to do, but don't -- if you're doing this, then you don't understand how it works because it's not really what you want to do.

[joevenzon]

For bumpiness, here's what I did in the listedit tool for road atlanta:

Code:

set 0 * 6 2.0
set 0 * 7 0.03
set 1 road* 7 0

The first two lines set all objects to have grass-y bump numbers (from vamos' concept of grass): 2.0 m bump wavelength, 0.03 m bump height. The third line sets all road objects to have 0 m bump height (no bumps).

[joevenzon]

For bumpiness, here's what I did in the listedit tool for road atlanta:

Code:

set 0 * 6 2.0
set 0 * 7 0.03
set 1 road* 7 0

The first two lines set all objects to have grass-y bump numbers (from vamos' concept of grass): 2.0 m bump wavelength, 0.03 m bump height. The third line sets all road objects to have 0 m bump height (no bumps).

[alex25]

Don't set any friction values larger than 1.0. It's possible to do, but don't -- if you're doing this, then you don't understand how it works because it's not really what you want to do.

i guess i was looking for the drag coefficient (in vamos-speak).

--alex--