Outerra forum

Outerra Engine => Development screen shots and videos => Topic started by: cameni on February 15, 2013, 09:45:49 am

Title: Adjustable center of mass, collisions between vehicles
Post by: cameni on February 15, 2013, 09:45:49 am
A short video showing the effects of changed center of mass position, together with collisions between vehicles.
Previously the physics simulation was stopped when you left the vehicle, but in the latest version the simulation continues. If you don't hold the brakes or if the vehicle isn't parked when you leave it, it will also continue rolling freely.

Adjustable center of mass, collisions between vehicles (http://www.youtube.com/watch?v=TyRybcicDBY#ws)
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: giucam on February 15, 2013, 09:51:49 am
When is the physics working? It obviously can't be on all the objects all the time, or else given enough objects the computer would explode. Is it active only when they are visible?
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: cameni on February 15, 2013, 09:59:36 am
Right now it's working all the time, but Bullet can deactivate objects if they are quiet.
Although due to a bug with friction it's never quiet at the moment ::)
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: Juggernautz on February 15, 2013, 11:51:11 am
I would assume you'd only want physics flagged objects to awaken in the closest LOD level for perf, though being able to adjust that setting would be cool.
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: Bartolomeus on February 15, 2013, 01:15:44 pm
Nice to see that the physics continues after leaving the vehicle. This would be nice for AI Traffic also. It is great to have the chance for changing the mass position. This parameter is very useful for changing the fuel or cargo of vehicles.

Marko
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: ZeosPantera on February 15, 2013, 01:44:46 pm
De-Mo-Lision.

Now you need multi-player because it is HYSTERICAL to watch you chase the other rolling vehicle..
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: ZeosPantera on February 16, 2013, 12:35:07 pm
Does the VEHICLE.CFG still apply? How are you editing the vehicle in-game. I can't get to that dialog.
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: cameni on February 16, 2013, 12:37:58 pm
Nope that's long gone. Script editor for vehicle physics script can be opened through alt+e, after you enter the vehicle.
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: ZeosPantera on February 22, 2013, 03:55:14 pm
I will ask you here since I cant find another dedicated vehicles thread.

You are going to have to add a terrain grip modifier to the terrain data and terrain type.. Setting the wheel slip per vehicle is fine if the whole world is made of the same material but with exposed rock, grass, sand, gravel and paved road and painted road you are going to need to have the slippage compound between the ground and tire.

I think a good solution once settled upon is a range of slip for each material.. IE (Sand : 35.0 - 42.0) (Asphalt : 57.0 - 62.5)

Then to better acclimate the vehicles tire type you would need two settings in the vehicles. "Compound" and "Tread"

A Compound Value being how well the tire material grips solid surface (rock and asphalt) and Tread Value being how well it grips on loose surfaces.. (Grass, Sand and gravel)

The mixture of those two items would produce a more realistic tire grip scenario. Just a though until a real tire model can be implemented.
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: cameni on February 23, 2013, 03:20:23 am
I will ask you here since I cant find another dedicated vehicles thread.
...
There was no question :)

What does "range of slip" exactly mean? I will be adding terrain type to the parameters for tire physics, but I'm still not entirely sure in what form. I though about a friction parameter that will produce the final friction value, considering the friction parameter of the tire.
Also, how to incorporate compound and tread. For given surface type I can have a value saying how much it is "compound" and how much "tread", so that a tire can use these values to compute the slip and whatever else.
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: ZeosPantera on February 23, 2013, 04:40:44 am
Yes. I didn't really have a question. More of a suggestion.

Range of slip being a given surface would have a varying amount of grip. All grass wouldn't be 100% the same traction. So a random amount more or less it is allowed to vary would be more realistic.

Everything else you said sounds exactly like I expected. Good Show.

Oh, any chance to get the JSBsim flight physics working to effect ground vehicles? I don't know what the library uses for giant boxes like the 8x8 but some wind resistance would help with spazzing vehicles hurtling though the air and come sports cars add additional, adjustable downforce to the mix. Drag might also help a problem I have found with cars over 100kph loosing their rear ends. So a drag variable to straiten that out.

Lastly before I forget. Any chance of allowing a dedicated reverse toggle button and leaving the gas and brake alone instead of the current system. With pedals it is a nightmare. I suppose you would need to add a "PARK" key as well OR two keys to slide up and down through Park>Reverse>Neutral>Drive>Low.. All just temporary measures until gears can be bound fully to controllers. That would allow at least a single low gear to be defined in vehicles too.
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: cameni on February 23, 2013, 06:24:33 am
Oh, any chance to get the JSBsim flight physics working to effect ground vehicles? I don't know what the library uses for giant boxes like the 8x8 but some wind resistance would help with spazzing vehicles hurtling though the air and come sports cars add additional, adjustable downforce to the mix. Drag might also help a problem I have found with cars over 100kph loosing their rear ends. So a drag variable to straiten that out.
I will just add a retarding force that depends on vehicle speedĀ² and Cx coefficient. There should be also a similar force acting as the internal friction of transmission, proportional to the speed.

Quote
Lastly before I forget. Any chance of allowing a dedicated reverse toggle button and leaving the gas and brake alone instead of the current system. With pedals it is a nightmare. I suppose you would need to add a "PARK" key as well OR two keys to slide up and down through Park>Reverse>Neutral>Drive>Low.. All just temporary measures until gears can be bound fully to controllers. That would allow at least a single low gear to be defined in vehicles too.
Only after the input system is incorporated into the scripting. Then the script can do anything.
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: ZeosPantera on February 24, 2013, 02:41:32 am
Question..

Is it possible with the current scripting and model handling to have a solid axle setup like this with bones and fixed wheels to an axle?

(http://image.4wdandsportutility.com/f/26014886/1002_4wd_05+2008_jeep_wrangler_jk_unlimited+teraFlex_LCG_suspension.jpg)


Oh. Just forgot to mention spring strength and suspension dampening should be options for front and rear independently (all corners really but that is super special stuff).
Title: Re: Adjustable center of mass, collisions between vehicles
Post by: cameni on February 24, 2013, 04:23:08 am
No, the wheel vectors (used for collision) can have only two configurations presently, half swing axle and vertical. Solid axles needs extra support.