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Car physics on a landscape. (3D)

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Ok i don''t want a 100 smooth engine here, just so you know i doesn''t have to bee too diffucult. I have 4 points under each wheel that defines the collision points for the wheels. I don''t whant an engine that have 100% collision detection for each of it''s polygons, but only a way to sumulate it have mass and movement when driving on the landscape. If i say that the weight of the Jeep is constant all over the place (not hevier in front or oppsite) and the wheels are rust mirrored. No special things here... How can i with this make an engine that can handle it''s movement? Like if the car drives over the edge of a mountain, how it would act on the way down...

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I''d say add an item to your car class as "intertia",

this way you''d add it or subtract it from your velocity, depending on the pitch of your car, ie. uphill or downhill. and also if you take the gas off, the car will still roll, and slow down gradually due to friction.

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I think, but I''m not sure, that this is what would happen: when the car goes over the cliff it should fall rapidly toward the ground below (after accelerating). You might not want to quote me on that, but I think that''s what would happen, right, it would fall down b/c of gravity?

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you want 3-dimensional moments of inertia. varying forces on the car (i.e. one wheel over cliff) add different torques to the system which effects it''s 3-dimensional rotation. so in the driving off the cliff example it''s far more complicated than just falling down (which obviously still happens). one wheel will fall off then anotehr than another then the last. at each point you''ll have differing torques on the system b/c gravity is pulling down on one or more wheels that have no ground underneath them. you''d end up with a tumbling car.

i guess look around for 3D versions of moments of inertia and torque. physics stuff.

-me

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Guest Anonymous Poster
ok, to do anything remotely realistic ur gona need a phsyics engine, read the demo on car physics search google (monstrous car physics tutorial) ur gona be amazed at first like woww, then apply it to your 3d model so that ur mdoel can drive around a flat plane, it looks cool, oh wiat now it shakes and stuff, the physics are unrealistic since they are only being handled for a car, what happens if hte car hits something, nothing, the demo dosn''t care, what happens if it hits a ramp, who cares, SEARCH FOR ODE open dynamics engine print the manual its stupid easy once u get the idea, also search for free fall shadow buggy demo that uses teh ode library and is open source so u can see how its done, then u will se how to do car phsycis the proper way, and not to mention the ability to get off the ground and interact with other objects

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After a little of thinking i think i can use 2d instead of just but with an extra height value... (2.5D)

I want simply to make a car drive on a heightmap and then later convert it to 3d.

(If my heightmap is a grayscale bitmap)

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Guest Anonymous Poster
if u simply put the cars wheels at the height for their x,z if u ut the car on a steap hill it will enlongate to a ratio of the hill, u can make the car stay the same length by finding the angle of your points, but then your car will be floating, with the contact points well in front and behind the car it self, sometiems goin over bumps u won''t be on the ground at all (take forinstance going from a zero inclide to a 80 degreee incline, the front wheels hight will sky rocket compared to the actual forward motoin) and ur car will levetate)

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I don''t understand.

If this guy is only manipulating 4 points, he needs to use
all this ODE, physics, jargon crap to simulate something??

What if he had only 1 point?

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Guest Anonymous Poster
i remember the last time a car touched the ground in one place

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Guest Anonymous Poster
<A HREF="http://freefall.freehosting.net/downloads/buggydemo.html">http://freefall.freehosting.net/downloads/buggydemo.htmlA> ___[link]http://freefall.freehosting.net/downloads/buggydemo.html[/link] _______________ Just look at this and u will see how good it is...

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Guest Anonymous Poster
are you sure its cause ur on a 98 machine, whats ur exact error, maybe ur missing a lib

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Guest Anonymous Poster
I would probably keep an intertia tensor for each of the five bodies (wheels + chassis) and then express the constraints to keep the items together and above ground as zeros in their dependent equation system.

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quote:
Original post by Anonymous Poster
are you sure its cause ur on a 98 machine, whats ur exact error, maybe ur missing a lib



The webpage says:
----------------------------
This application requires Windows 2000/XP, DirectX 8.1 and a video card that has a stencil buffer.
----------------------------

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