Real-Time Physics Simulation Forum

This is not a complete description of the modification since I have modified more things in the height field class. Just see processTrianglesAlongLine as pseudo code for how to improve the speed for line intersections. The code assume that btScalar is defined as float since that is what I use. Some ...

The inside would be concave and can't use convex to convex collision algorithms. It would be easier to just have a btBvhTriangleMeshShape and keep it static.

You do not have to make your own collision algorithm for static triangle shapes. If you inherit btConcaveShape like in the heightfield class does, the engine will call processAllTriangles with an AABB for the section that it is interested in and use it for collisions.

Since the convex hull optimizer that I tried caused my low detailed convex hulls to become more complex than before, I made a new convex hull optimizer that will remove every point inside the convex hull without adding any new points given that the input does not have any close pair of points. To re...

Are you defining btScalar as a 64 bit float?

I am trying to optimize the Bullet engine by keeping a non allocating double link list of each active rigid body so that the world don't have to ask each sleeping body if it is active. The only thing missing is a way to know when a rigid body has changed it's activation state so that isActive() give...

You might be able to make your own friction function. Use a low viscous friction and a high stribeck friction to make the wheels loose grip when spinning.

Each size of the cube need a different shape.

Even on the same version of Windows, different CPUs do floatingpoint calculations in different ways so that the result is noticeably different after a divergent simulation.

If your character is a round shape then you only need to rotate the visual representation. By running backwards and sidestepping, your character can change direction using a fast acceleration while the direction is slowly turning to the walking direction. The head can turn to the walking direction f...

I would use a compound shape for each heavy body so that the small details will always be in the right place.
You can also use class inheritance if you want to modify the engine while still being able to upgrade to a new version of Bullet.

The default broadphase is using a dynamic tree for each group of bodies and therefor the lookup cost for small dynamic bodies is only O(log n) where n is the number of static bodies. My game use thousands of static bodies without any problem.

You must remove the object from the world before deleting it.

A wrapper might give some built in functionality for debug drawing and synchronization with graphical objects.

I recomend that you make a collision shape that generate triangles from a dynamic octree.

I don't see how one can be removed without forcing a lot of people to rewrite their code.