Search found 149 matches

by c6burns
Tue Jul 01, 2014 1:39 pm
Forum: General Bullet Physics Support and Feedback
Topic: CollisionShapes on animated mesh (skeletal)
Replies: 3
Views: 3584

Re: CollisionShapes on animated mesh (skeletal)

You do have access to the transformed bones on the CPU side. So one option is to use kinematic primitives kept in alignment to the bones in order to make a close approximation to the actual character.
by c6burns
Mon Jun 23, 2014 5:16 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 10300

Re: Set the axes on BTGeneric6DofConstraint and lock/unlock

There's a constructor to build a btMatrix3x3 from 3 axes, if that's what you mean: /** @brief Constructor with row major formatting */ btMatrix3x3(const btScalar& xx, const btScalar& xy, const btScalar& xz, const btScalar& yx, const btScalar& yy, const btScalar& yz, const btScalar& zx, const btScala...
by c6burns
Mon Jun 23, 2014 4:36 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 10300

Re: Set the axes on BTGeneric6DofConstraint and lock/unlock

It means if you want to swivel or offset the constraint on either end, you can do so in local coords. So, just for a moment, we can imagine the constraint as a rope between a tree branch and a tire swing ... not exactly relevant to a 6dof but oh well. Now you can offset the position or rotation (bas...
by c6burns
Mon Jun 23, 2014 4:09 pm
Forum: General Bullet Physics Support and Feedback
Topic: build error for bullet-2.82-r2704 for ios and my xcode is 5
Replies: 7
Views: 4275

Re: build error for bullet-2.82-r2704 for ios and my xcode i

IMHO the error is that code signing is required for iOS deployment and you haven't set it up.

Also, can't you generate an xcode5 project using CMake? Also also, you can just add the cpp files you need directly in an existing project if it comes down to it.
by c6burns
Mon Jun 23, 2014 2:46 pm
Forum: General Bullet Physics Support and Feedback
Topic: Local /global coordinates (why always local ?)
Replies: 8
Views: 4178

Re: Local /global coordinates (why always local ?)

Hmmm I don't know, I am seriously bad at math (for a programmer). High school level algebra. Ogre is my crutch :) I have learned a lot from digging into its implementations, like Node::convertWorldToLocalPosition and Node::convertWorldToLocalOrientation
by c6burns
Mon Jun 23, 2014 2:12 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 10300

Re: Set the axes on BTGeneric6DofConstraint and lock/unlock

setAngularLowerLimit/setAngularUpperLimit are for angular motion. If you are talking about linear motion you would use setLinearLowerLimit/setLinearUpperLimit. And yes, setting all limits to btVector3(0,0,0) would completely lock motion. You can really learn a lot by playing with the constraint demo...
by c6burns
Mon Jun 23, 2014 1:58 pm
Forum: General Bullet Physics Support and Feedback
Topic: Local /global coordinates (why always local ?)
Replies: 8
Views: 4178

Re: Local /global coordinates (why always local ?)

I'm pretty much the worst mathematician I know, and I don't have a problem translating between coordinate spaces. But if you think it should be in the library you can always submit a patch.
by c6burns
Mon Jun 23, 2014 7:15 am
Forum: General Bullet Physics Support and Feedback
Topic: build error for bullet-2.82-r2704 for ios and my xcode is 5
Replies: 7
Views: 4275

Re: build error for bullet-2.82-r2704 for ios and my xcode i

I think it's more that you haven't set up a provisioning profile. I bet if you literally cut and paste that output into google there with be a stackoverflow post from someone who has done the same.
by c6burns
Mon Jun 23, 2014 3:58 am
Forum: General Bullet Physics Support and Feedback
Topic: Local /global coordinates (why always local ?)
Replies: 8
Views: 4178

Re: Local /global coordinates (why always local ?)

Basroil wrote:Ever worked with an 18dof robotic snake?
Haven't we ALL?

Hint: no
by c6burns
Mon Jun 23, 2014 2:21 am
Forum: General Bullet Physics Support and Feedback
Topic: Local /global coordinates (why always local ?)
Replies: 8
Views: 4178

Re: Local /global coordinates (why always local ?)

Local makes sense to me. As you even mention, you can just translate world to local if you like.
by c6burns
Fri Jun 20, 2014 1:15 am
Forum: General Bullet Physics Support and Feedback
Topic: Restricting movement of a RigidBody onto an arbitrary plane.
Replies: 6
Views: 4048

Re: Restricting movement of a RigidBody onto an arbitrary pl

My understanding is that those transforms express the pivot of the constraint in local coordinates. For example, you can tilt the entire 6dof slide in the constraint demo by specifying a rotation. As for the other concerns about the merits of this as a solution to the original problem, I really can'...
by c6burns
Thu Jun 19, 2014 11:29 pm
Forum: General Bullet Physics Support and Feedback
Topic: Restricting movement of a RigidBody onto an arbitrary plane.
Replies: 6
Views: 4048

Re: Restricting movement of a RigidBody onto an arbitrary pl

I also am not really seeing how to use the 6Dof constraint to lock to a plane that isn't axis aligned. If I am missing something that makes that happen, please let me know.
By using the transforms taken as parameters to the constraint's constructor
by c6burns
Fri May 30, 2014 1:21 pm
Forum: General Bullet Physics Support and Feedback
Topic: Softbody help
Replies: 9
Views: 5117

Re: Softbody help

No worries. I did a very simple implementation of btsoftbody in Ogre and there was no way I ever would have completed it without debug drawing (and a lot of debugging and referencing the softbody samples)
by c6burns
Tue May 27, 2014 12:29 am
Forum: General Bullet Physics Support and Feedback
Topic: Softbody help
Replies: 9
Views: 5117

Re: Softbody help

I do not have debugdraw yet
You are trying to get softbodies working but you haven't taken care of debug draw. You are trying to cartwheel before you walk.
by c6burns
Tue May 20, 2014 4:37 am
Forum: General Bullet Physics Support and Feedback
Topic: What is bullet world size limits
Replies: 3
Views: 2960

Re: What is bullet world size limits

This sounds like an issue of floating point accuracy. You need to either scale down the world, or use double precision floats (by rebuilding bullet to do so), or both.