![]() Since everything is ball-joint, you must triangulate everything, and you can always obtain other joints by contruction (many extra triangulation beams are masked in trucks). You observe that the truck has a center of inertia, moments of intertia, you name it, but it is never explicitely computed. ![]() Yet the simulation is realistic : all the rigid body "laws" emerge from the interaction of nodes. Also I do not compute anything central (center of inertia) and in fact if you split the truck in two, the two parts move independentely and realistically (I have seen impressive wheels run-offs). I just compute nodes movements, and nodes are dimension-less objects. The consequence is that I do not have to compute anything that has to do with angles (rotational speeds and moments. The good news is that the model is extremely simple : I simulate monodimensional beams connected by ball-joint. I hope that with a Runge Kutta intergrator it will require less steps per second. This version uses a simple Euler integrator, with 100 integration steps per frame, and a capping at 20fps (below 20fps, the simulation is not realtime), so the integration steps are never below 1/2000th second (with several hundred nodes to compute)!!! And even with that, the chassis is not as rigid as I would want. Yes, a spring array is a good way to model a vehicle, but the springs must be very, very strong so the integrator must run on very small time steps to avoid instabilities. ![]() Screenshots are here: and a big thanks to the Ogre team for their marvelous work! This is still a work in progress, but it is downloadable as is at: īEWARE: the physics engine is very CPU intensive and the game won't run without at least a 3GHz processor!!! Progress has still to be made to improve the engine efficiency (it still runs on a basic Euler integrator). (making deformable meshes in Ogre is a little less funny, not to mention shadows that are still missing) The result is a deformable chassis and deformable tires (which are also made of beams) and lots of fun to drive. ![]() Loads are computed on each beams, which deforms according to the load. The physics engine is not a rigid-body type, but a soft-body based on particles network. I used Ogre 1.0 for the graphics, Audiere for sounds and I developped the physics engine. ![]() Here is my first game: it is an offroad truck simulator. ![]()
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