Search found 20 matches
- Wed May 31, 2017 2:37 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Non-smooth sliding.
- Replies: 0
- Views: 4651
Non-smooth sliding.
I had observed that friction appeared to be less stable in Bullet than in ODE or PhysX for a given friction coefficient. To convince myself of this I created a simple test case consisting of a 10 degree angled ramp with some small boxes to slide down the ramp. Each box has a mass of 1kg and dimensio...
- Fri Nov 04, 2016 12:56 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: CPU multithreading is working!
- Replies: 145
- Views: 1286377
Re: CPU multithreading is working!
Yes please! I'd love to see this added.lunkhound wrote:On the graph coloring constraint solver, I may take a crack at that. I'd really like to see that too.
- Tue Oct 04, 2016 4:11 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Two Outstanding Issues
- Replies: 7
- Views: 12560
Re: Two Outstanding Issues
What is the type of your level geometry (in particular, what is the geometry type for your rings)?
- Tue Aug 16, 2016 11:16 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Dynamically adding Collision filtering on rigid bodies
- Replies: 3
- Views: 5654
Re: Dynamically adding Collision filtering on rigid bodies
You need to remove and re-add the rigid body to the world.
- Wed Aug 10, 2016 1:34 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: CPU multithreading is working!
- Replies: 145
- Views: 1286377
Re: CPU multithreading is working!
I don't know if this project is active anymore, but I sometimes get crashes when using constraints that can be constrained against the world. In such cases, Bullet actually constrains the rigid body against what it calls a "fixed body" - see btTypedConstraint::getFixedBody(). The fixed bod...
- Sat May 21, 2016 2:29 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Problems/Understanding contactTest
- Replies: 1
- Views: 4924
Re: Problems/Understanding contactTest
Have you tried using btTriangleShape rather than btConvexTriangleMeshShape? Using btConvexTriangleMeshShape will cause the Convex-Convex collision algorithm to be used. I don't know the inner workings of the GJK-EPA algorithm and so I don't know whether it supports zero volume convex shapes. But if ...
- Sat May 21, 2016 2:00 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Quaternion changes rotation when initializing
- Replies: 7
- Views: 12795
Re: Quaternion changes rotation when initializing
Use btQuaternion::setEuler, btQuaternion::setRotation, or the two corresponding constructors to properly initialize your quaternion. As drleviathan said, only unit quaternions represent rotations. The vector part of the quaternion (x, y, z), also referred to as the imaginary part, are not the Euler ...
- Thu May 19, 2016 4:47 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Missing/disabled sphere-box collision algorithm.
- Replies: 0
- Views: 5217
Missing/disabled sphere-box collision algorithm.
I have been having some issues where spheres would fall through large boxes (one side > 1000 units). After a little investigation I found that the sphere-box algorithm is disabled (buggy?) and so I think that the GJK/EPA implementation is currently being used. So, in case anyone is interested, here ...
- Fri Apr 01, 2016 4:47 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Collisions with Nested Compound Shapes
- Replies: 6
- Views: 10477
Re: Collisions with Nested Compound Shapes
Looks good. I noticed today that the m_index0 and m_index1 fields don't work as assumed when the compound contains gImpact trimesh shapes. I logged this on github: https://github.com/bulletphysics/bullet3/issues/588
I think your solution should work in this case also.
I think your solution should work in this case also.
- Tue Mar 29, 2016 5:44 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: [Solved] Change Collision Mask require re-add Constraint?
- Replies: 2
- Views: 5179
Re: Does change Collision Mask require remove/re-add Constra
I'm fairly sure that you don't. Well, at least I haven't needed to in my test cases.
- Tue Mar 29, 2016 5:41 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Scan area for intersecting shapes.
- Replies: 8
- Views: 18954
Re: Scan area for intersecting shapes.
Yes, you should get contact points even when the other object's collision shape is completely inside of your box collision shape. To be clear, the collision detection detects when pairs of shapes are overlapping/intersecting. This includes cases where one shape completely encompasses another.
- Wed Mar 23, 2016 6:27 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Scan area for intersecting shapes.
- Replies: 8
- Views: 18954
Re: Scan area for intersecting shapes.
You should get contact points when one shape intersects with another, either partially or fully. From the btPersistentManifold you can get the pair of collision objects involved. Unless I have misunderstood what you're after, this is really very simple. You can use contactTest, which executes outsid...
- Thu Mar 03, 2016 11:17 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Pulsating bounding boxes
- Replies: 1
- Views: 3752
Pulsating bounding boxes
Does anyone know why the size of the AABBs pulsate when the associated rigid body is rotating? For example, the size of the AABB for a capsule will oscillate when the capsule is just rolling on its side. See also the following video of a kinematic body with just a cylinder collision shape: https://g...
- Wed Mar 02, 2016 12:37 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Collisions with Nested Compound Shapes
- Replies: 6
- Views: 10477
Re: Collisions with Nested Compound Shapes
Ah, ok. I'm coming from ODE which has kind of an inverse relationship to Bullet, where Geoms (collision shapes) "have" a rigid body rather than the other way round. Because of this I chose to enforce that collision shapes belong to at most one collision object. Hence I wouldn't have any is...
- Tue Mar 01, 2016 3:57 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: Collisions with Nested Compound Shapes
- Replies: 6
- Views: 10477
Re: Collisions with Nested Compound Shapes
I'm interested in this also. It's been at the back of my head and I haven't really thought about it much.
Would it not be more simple to just store a pointer to the collision shape in btManinfoldPoint? Storing indices and then traversing the compound tree just seems to add a lot of unnecessary work.
Would it not be more simple to just store a pointer to the collision shape in btManinfoldPoint? Storing indices and then traversing the compound tree just seems to add a lot of unnecessary work.