Real-Time Physics Simulation Forum

I don't know about your specific case, but if it's anything like the collision callback function, you can just cast the btCollisionObjectWrapper as you need to. For example, in my project I have: bool btCallback(btManifoldPoint& cp,const btCollisionObjectWrapper* obj1,int id1,int index1,const bt...

Unfortunately, I don't have much to suggest; I've been trying to solve the same problem with other constraint types and haven't had much luck. Try searching these forums for BT_CONSTRAINT_STOP_CFM and BT_CONSTRAINT_STOP_ERP. I don't fully understand what these parameters do and how they work, but pl...

I've seen these errors a bunch while trying to integrate Bullet with some other code. Such a headache (especially since I've never dealt with MSVS until this project!). From my understanding, this occurs when you include a .h file that has a function prototype but the corresponding definition (usual...

I found this thread after some searching http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=3303&hilit=shift+demo and tried to cannibalize the relevant parts in the hopes that I could get Bullet to figure out the center of mass for me: //convexhull hexahedron (not centered on the...

Thanks, guys! I managed to build my dynamic hexahedron using btConvexHullShape. The center of gravity thing is kind of annoying, though... that's going to make placing my objects a headache. Do you know of any way to get Bullet to calculate a new center of gravity so I don't have to figure it out fo...

Well, I found some problems with my self-determined triangle mesh, so I modified it a bit. This makes me really wish I knew how to get the mesh from the proprietary software I'm using... even getting the vertexes from 12 triangles is a pain! I made the changes below, but it still crashes in the same...

The method posted above seems to work, but I think I'm doing something wrong somewhere because I can't get my shape to work if it's not static. I just stuck it into AppBasicDemo like this: //Triangle mesh hexahedron btTriangleMesh *mTriMesh = new btTriangleMesh(); // For whatever your source of tria...

Thanks for that! I'll play around with it and see if it gives what I need. In the meantime, any other suggestions are welcome.

Hi all. I have what I think should be an easy question. How do I create polyhedrons in Bullet that aren't boxes? I'm trying to build a physics approximation of some complex geometry and it would be helpful to be able to make shapes like the one I've included (a hexahedron). Apologies if I've missed ...

I know this is a month-old post, but in case others are wondering how to get collisions up and running somewhat quickly, this video tutorial helped me immensely: http://www.youtube.com/watch?v=YweNArzAHs4 This particular video deals with collisions, but starting with part 0, it walks you through Bul...

I've only just begun working with Bullet, so I'm no expert, but it sounds like you could use some additional constraints to hold one of your bodies in place. Check out the Constraint Demo. It has a ton of examples of how you can fasten things in place. You may want to change your hinge constraint in...

I managed to work out an inelegant but workable solution. I stuck a static block on top of the catapult base to physically stop the butt end of the launch arm when it goes too far. I also added a "latch" constraint between the launch arm and the base (just a 6Dof constraint with all degree...

So, I figured out the angle settings from my previous post (I was right), but still have some questions. Here's the code I'm using for this example: //launchBeam * crossBeam frameInA = btTransform::getIdentity(); frameInA.setOrigin(btVector3(0, 0, scale*1.5)); frameInB = btTransform::getIdentity(); ...

I'm no expert on Bullet, but in my reading I've come across some mention of rolling friction. Since you're using a sphere on a flat surface, maybe that's what you need?

Certainly not, but I'm asking if Bullet has any quirks that may differ from my pencil and paper, where I define everything. Starting simply, with something that should be easy to test, does my angular upper limit of 90 degrees correspond to a vertical catapult? In Bullet, is that limit a hard limit,...