Search found 27 matches

by kester
Tue Dec 13, 2011 8:35 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: driving game
Replies: 32
Views: 54894

Re: driving game

Hi, The normals, positions and indices I used came from the collision mesh for my road. There's a lot of work not really mentioned in my article: you need to implement a btStridingMeshInterface class to provide the normals, implement ray-cast callbacks, and the vehicle ray-caster to override the whe...
by kester
Thu Nov 04, 2010 8:30 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Blood Drive uses Bullet
Replies: 2
Views: 9526

Blood Drive uses Bullet

Hi everyone, Blood Drive for PS3 and Xbox 360 uses Bullet. Trailers here:: http://www.gametrailers.com/game/blood-drive/13910 Blood Drive is a car combat, zombie running-over kind of game. Press Release: http://www.gamasutra.com/view/pressreleases/64878/Activisionrsquos_Blood_DriveTM_infects_stores_...
by kester
Mon Nov 01, 2010 11:32 am
Forum: General Bullet Physics Support and Feedback
Topic: Autonomous driving
Replies: 8
Views: 6126

Re: Autonomous driving

We use Detour (http://code.google.com/p/recastnavigation/) for navmesh generation and path finding. To make a vehicle drive, you need to: 1. Work out what direction to go (eg path find) 2. Set your steering so that the wheels point in the direction you want to go. 3. Tune the engine force/steering s...
by kester
Fri Jun 11, 2010 9:04 am
Forum: General Bullet Physics Support and Feedback
Topic: VFP optimizations for iPhone ARM
Replies: 11
Views: 13322

Re: VFP optimizations for iPhone ARM

If you are porting the constraint solver, there are a couple of improvements you can make for most vector units: 1. The dot products are not usually implemented in hardware very well. Instead of dot(n, v1) - dot(n, v2) + dot(pxn1, w1) + dot(pxn2, w2), you can write: dot( n * v1 - n * v2 + pxn1 * w1 ...
by kester
Wed Jun 09, 2010 3:30 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: driving game
Replies: 32
Views: 54894

Re: driving game

castRay performs a ray-cast, which returns the triangle index, part id, collision object, and hit position of the end of the ray.

You can use the triangle index to work out which vertices form the hit triangle.
by kester
Sun Dec 13, 2009 10:08 pm
Forum: General Bullet Physics Support and Feedback
Topic: Bumpy triangle meshes
Replies: 71
Views: 71861

Re: Bumpy triangle meshes

All my world meshes are one-sided, so I always use the triangle normal (even if collision_normal.dot(tri_normal) < 0.0)

I think instrumenting the edges is probably the way to go though, but I couldn't afford the memory or time to investigate it.
by kester
Wed Dec 02, 2009 9:54 pm
Forum: General Bullet Physics Support and Feedback
Topic: Bumpy triangle meshes
Replies: 71
Views: 71861

Re: Bumpy triangle meshes

I found when using the triangle normal that the contact point had to be reprojected. Otherwise the contact would break since the movement orthogonal to (new) normal was too large: /// Changes a btManifoldPoint collision normal to the normal from the mesh. static void FixMeshNormal(btManifoldPoint&am...
by kester
Fri Nov 13, 2009 4:24 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: HotWheels: Battle Force 5 for Wii uses Bullet
Replies: 0
Views: 7721

HotWheels: Battle Force 5 for Wii uses Bullet

HotWheels: Battle Force 5 for Wii uses Bullet for collision detection, dynamics, and vehicle simulation. Official Page: http://www.activision.com/index.html#gamepage|en_US|gameId:BF5&brandId:BattleForce5 HotWheels is a driving adventure game. There are 16 different vehicles, ranging from one whe...
by kester
Mon Nov 09, 2009 5:16 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: driving game
Replies: 32
Views: 54894

Re: driving game

It's good to hear that it's working!

Adding it by default to Bullet probably requires some quite invasive changes. It's quite a bit of work just for vehicle simulation. I think you'd only want to add it to the 'mesh' shapes: the bvh tri mesh shape, and the heightfield terrain shape.
by kester
Wed Nov 04, 2009 9:36 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: How to access Wii and Xbox360
Replies: 2
Views: 5541

Re: How to access Wii and Xbox360

Yes, porting Bullet to a new platform is pretty easy. You just need to throw all the source into a project, and go through btScalar.h adding implementations for your compiler.
by kester
Wed Nov 04, 2009 12:51 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: driving game
Replies: 32
Views: 54894

Re: driving game

It seems weird that you're getting coordinates outside the triangle. I'm using btBvhTriangleMesh shape, and I get valid positions. I was thinking also, when overriding these things, it should also be possible to use a normal map and return a normal from that... a bit more math required though. Anyon...
by kester
Fri Oct 30, 2009 12:55 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: driving game
Replies: 32
Views: 54894

Re: driving game

:?: I suspect everyone "pushes" their vehicles rather than torquing the wheels. True? If you're setting m_engineForce, then that's effectively the torque from the wheels. This is clamped to the friction limits and applied to the chassis. This is good, because it's simple and easy. It does...
by kester
Thu Oct 29, 2009 8:23 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: driving game
Replies: 32
Views: 54894

Re: driving game

The force is clamped after mass is factored in, so you are probably hitting the maximum suspension impulse limits (I've upped the 6000 limit to 100000). Our lightest vehicle's mass is 500kg, and the heaviest is 4000kg. The suspension stiffness ranges from 10.0 to 200.0. It's good to know my notes ar...
by kester
Wed Oct 28, 2009 8:45 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: driving game
Replies: 32
Views: 54894

Re: driving game

The suspension force also depends on the contact normal, so it smooths out the bump on polygon edges. :-)
by kester
Wed Oct 28, 2009 8:29 pm
Forum: General Bullet Physics Support and Feedback
Topic: Vehicle suspension question
Replies: 6
Views: 5419

Re: Vehicle suspension question

Thank you kester. I have noticed the one down fall to that code which is that if the vehicle is stationary, the suspension will gradually drop until the chassis touches. I was just curious to see if you had worked out some way to prevent that? Also, I just wanted to say, excellent notes and comment...