Search found 19 matches

by tmason
Wed Jan 14, 2015 5:31 am
Forum: General Bullet Physics Support and Feedback
Topic: btConvexTriangleMeshShape
Replies: 2
Views: 2112

Re: btConvexTriangleMeshShape

btBvhTriangleMeshShape and btConvexTriangleMeshShape objects are designed to be non-moving in the Bullet physics world and thus won't have an inertia; the calculateLocalInertia() call fails by design.

As mentioned by xexuxjy you need to use objects specifically designed to be dynamic.
by tmason
Sun Dec 21, 2014 11:40 am
Forum: General Bullet Physics Support and Feedback
Topic: Importing Terrain
Replies: 3
Views: 2961

Re: Importing Terrain

xexuxjy wrote:not quite true, btTerrainShape can be updated pretty easily to use either of those formats as all you really want from them is a height value at x,y which can correspond to a grayscale (or whatever) value from your image.
Fair enough; I stand corrected.
by tmason
Fri Dec 19, 2014 12:01 am
Forum: General Bullet Physics Support and Feedback
Topic: Converting loaded Static Mesh to a Convex Hull (Or Similar).
Replies: 3
Views: 3234

Re: Converting loaded Static Mesh to a Convex Hull (Or Simil

c6burns wrote:In my opinion, for something like this you are going to end up removing the original body from the world and adding another body in its place.
I see; my assumption is that you can copy the motion state, scaling, etc. from the original body into my animated body.

Correct?
by tmason
Thu Dec 18, 2014 11:09 pm
Forum: General Bullet Physics Support and Feedback
Topic: Converting loaded Static Mesh to a Convex Hull (Or Similar).
Replies: 3
Views: 3234

Converting loaded Static Mesh to a Convex Hull (Or Similar).

Hello, I have more of a best practices kind of question. So I have a working Bullet Physics implementation with walking camera, dynamically insertable/deletable objects like boxes, and a dynamically loaded mesh from file. So far so good; basically I can load a static mesh and walk through the enviro...
by tmason
Thu Dec 18, 2014 6:54 am
Forum: General Bullet Physics Support and Feedback
Topic: Importing Terrain
Replies: 3
Views: 2961

Re: Importing Terrain

If I have terrain data of some other form, such as JPEG 2000, ArcGrid, IMG, GeoTiff, etc, how can I go about creating either of the above two objects in Bullet? I'm not really familiar with handling terrain data in general, so I apologize if this is a common question. You can't and in the examples ...
by tmason
Sun Dec 14, 2014 4:50 am
Forum: General Bullet Physics Support and Feedback
Topic: Latest Bullet Build for CPU vs GPU ...
Replies: 2
Views: 2346

Re: Latest Bullet Build for CPU vs GPU ...

Just ignore the fact that the repository says bullet3 and build as normal. Resulting libraries will be the same you are used to from 2.x (LinearMath, BulletDynamics, BulletCollision, and so on) You can disable building bullet3 at all in CMake using BUILD_BULLET3 (which will appear as a checkbox if ...
by tmason
Sun Dec 14, 2014 1:41 am
Forum: General Bullet Physics Support and Feedback
Topic: Latest Bullet Build for CPU vs GPU ...
Replies: 2
Views: 2346

Latest Bullet Build for CPU vs GPU ...

Hello, My guess is that this is a simple question but maybe it is me and I am not quite clear. I understand that Bullet 3.x is graphics card only but from what I am seeing from the commits Bullet 2.x is still being updated as well. So, I would like to update my currently working project which uses a...
by tmason
Fri Oct 24, 2014 3:46 pm
Forum: General Bullet Physics Support and Feedback
Topic: Ghost Object collide with Soft Bodies?
Replies: 4
Views: 4149

Re: Ghost Object collide with Soft Bodies?

Is it possible to post the code that you are using? At least for the initialization of the objects but preferably for everything else?
by tmason
Tue Oct 21, 2014 6:12 pm
Forum: General Bullet Physics Support and Feedback
Topic: Simple question regarding gravity...
Replies: 2
Views: 2380

Simple question regarding gravity...

Hello, So I have the Bullet Physics engine up and running within my application and so far all looks good. I do have a question about gravity; in my environment gravity works 100% but it is only a linear velocity applied for it; not natural acceleration. So it seems like things operate in slow motio...
by tmason
Fri Oct 17, 2014 3:41 am
Forum: General Bullet Physics Support and Feedback
Topic: Reliably obtaining rotations for OPENGL
Replies: 2
Views: 3288

Re: Reliably obtaining rotations for OPENGL

Something like this: btTransform CurrentPhysicsPosition = btTransform(); PhysicsShapeRigidBody->getMotionState()->getWorldTransform(CurrentPhysicsPosition); CurrentPhysicsPosition.getOpenGLMatrix(glm::value_ptr(ModelMatrix)); ModelMatrix *= glm::scale(ObjectScale); In this case, I use the btTransfor...
by tmason
Thu Sep 18, 2014 9:59 am
Forum: General Bullet Physics Support and Feedback
Topic: Change Height/Radius of Capsule Object when Loaded in world?
Replies: 2
Views: 2238

Re: Change Height/Radius of Capsule Object when Loaded in wo

Thanks, seems like this should work.

If I can avoid deleting and reading the object all the better.
by tmason
Wed Sep 17, 2014 7:43 pm
Forum: General Bullet Physics Support and Feedback
Topic: Change Height/Radius of Capsule Object when Loaded in world?
Replies: 2
Views: 2238

Change Height/Radius of Capsule Object when Loaded in world?

Hello, I have hopefully a simple question: I have a btCapsuleShape collision shape setup I am using as a simple character controller and it works decently. Now I need to be able to change the width and height of the shape live in the environment; I tried recreating the shape within the environment b...
by tmason
Sat Sep 06, 2014 11:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: Getting the MultiThreaded Example/Demo to Work ...
Replies: 1
Views: 2536

Getting the MultiThreaded Example/Demo to Work ...

Hello, I have attempted to compile and use the multithreaded example that comes with the Bullet Source without success. I get the following set of errors: 1>MultiThreadedDemo.obj : error LNK2019: unresolved external symbol "public: __thiscall SpuGatheringCollisionDispatcher::SpuGatheringCollisionDis...
by tmason
Thu Sep 04, 2014 12:22 pm
Forum: General Bullet Physics Support and Feedback
Topic: Best approach for large scenes with static mesh ...
Replies: 0
Views: 2922

Best approach for large scenes with static mesh ...

Hello, I am building an engine that supports importing mesh from large FBX files. I can get the scene to load fine and have basic interaction with the scene but when I start attempting to interact with the scene even using basic objects I get serious performance degradation. My goal is to get a walk...
by tmason
Sun Aug 31, 2014 12:14 pm
Forum: General Bullet Physics Support and Feedback
Topic: Rotating an object representing the ground (Mass = 0)
Replies: 4
Views: 2996

Re: Rotating an object representing the ground (Mass = 0)

STTrife wrote:I think you can do that with btRigidBody::setDamping (btScalar lin_damping, btScalar ang_damping).
Thank you again!

Works; exactly what I needed :)