Search found 456 matches

by Flix
Thu Feb 25, 2010 12:56 pm
Forum: General Bullet Physics Support and Feedback
Topic: kinematic > static collision detection
Replies: 5
Views: 4611

Re: kinematic > static collision detection

For example when a character (kinematic) go through some volume in the scene (static). Can Bullet detect such collision? Kinematic bodies can't collide with static bodies in Bullet: that's one reason why a (kinematic) character controller must be used in this situation. There's a demo about it. The...
by Flix
Tue Feb 23, 2010 3:02 pm
Forum: General Bullet Physics Support and Feedback
Topic: Questions about serialization and contact query
Replies: 2
Views: 1403

Re: Questions about serialization and contact query

Thanks for all your clarifications.
Flix.
by Flix
Sun Feb 21, 2010 9:49 am
Forum: General Bullet Physics Support and Feedback
Topic: Questions about serialization and contact query
Replies: 2
Views: 1403

Questions about serialization and contact query

Some quick questions about recent Bullet features: Serialization: 1) I've seen that it's possible to serialize/deserialize objects to/from memory. Based on this, is there some robust code snippet around to clone physic bodies? 2) Is it complete ? (i.e. can I serialize/deserialize all kind of constra...
by Flix
Sun Feb 21, 2010 9:26 am
Forum: General Bullet Physics Support and Feedback
Topic: Ogre + Bullet combination - best practices?
Replies: 13
Views: 9403

Re: Ogre + Bullet combination - best practices?

Just to say that I've been using Ogre and Bullet together for some year, and what I did was to derive a physic model (verts + inds) from an Ogre mesh by removing double vertices. This way vertices can be reduces about by 20% (or even more on some meshes) and the performance is better. The main probl...
by Flix
Sun Feb 07, 2010 9:13 am
Forum: General Bullet Physics Support and Feedback
Topic: Help with sphere...
Replies: 7
Views: 3135

Re: Help with sphere...

2) How to add bend to an object, i think its called centripical force, like a curve ball in baseball? I thought it was called Bernoulli force... Anyway, as far as I remember, that force is caused by the friction between the body surface and a fluid (air), and of course it can't be applied by Bullet...
by Flix
Sun Jan 31, 2010 9:25 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Hinge2Vehicle Demo (with source code)
Replies: 1
Views: 8549

Re: Hinge2Vehicle Demo (with source code)

Here is a pic of the demo in action:
HingeVehiclesDemo.JPG
HingeVehiclesDemo.JPG (16.68 KiB) Viewed 8547 times
And this is a raytrace screenshot of the most complex wheel collision shape included in the demo (I named it btWheelShape AFAIR), added to show it better:
wheelShape2.JPG
wheelShape2.JPG (9.63 KiB) Viewed 8547 times
by Flix
Sun Jan 31, 2010 9:19 am
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Hinge2Vehicle Demo (with source code)
Replies: 1
Views: 8549

Hinge2Vehicle Demo (with source code)

WHAT'S THIS? This is a demo about vehicles without raycasting. IMPLEMENTATION NOTES: I used a btHinge2Constraint for the wheels, but I disabled the (vertical) suspension spring, because I couldn't find a good setting for it, and I replaced it with a vertical translational motor. Thus now the suspen...
by Flix
Tue Jan 12, 2010 2:46 pm
Forum: General Bullet Physics Support and Feedback
Topic: btTransform and Compound Shape Construction question
Replies: 3
Views: 3049

Re: btTransform and Compound Shape Construction question

what does mean this code? the rotation Is only in the place of the object? Sure, you were adding the same body in btVector3(0,0,radius), each time with a different orientation (rotation in Bullet means body orientation most of the time). You need to modify the position (origin) of the child transfo...
by Flix
Sun Jan 10, 2010 9:17 am
Forum: General Bullet Physics Support and Feedback
Topic: Specifying correct btCylinderShape
Replies: 2
Views: 2859

Re: Specifying correct btCylinderShape

How does one interpret the halfExtents vector for btCylinderShape? For example, if I have a cylinder of radius 3 and height 1, what would be the correct btCylinderShape vector here?
Without testingt, I'd say:
btCylinderShape* shape = new btCylinderShape(btVector3(radius,height*0.5,radius));
by Flix
Tue Jan 05, 2010 2:16 pm
Forum: General Bullet Physics Support and Feedback
Topic: Unilateral collision response using masks.
Replies: 1
Views: 1855

Re: Unilateral collision response using masks.

I would just assign a very low mass to the debris, so that they don't interfere with the player trajectory. Many times this simple solution works (I've tested it with my collision camera). You can assign a good damping factor or something like that to limit the debris speed due to collisions. Don't ...
by Flix
Sun Dec 27, 2009 9:29 am
Forum: General Bullet Physics Support and Feedback
Topic: Matrix rotation values
Replies: 1
Views: 1184

Re: Matrix rotation values

I don't know if this depends on the conventions you're using or not. AFAIK in my case: myTransform.getBasis().getColumn(0) is the X-axis (left) in global space. myTransform.getBasis().getColumn(1) is the Y-axis (up) in global space. myTransform.getBasis().getColumn(2) is the Z-axis (forward) in glob...
by Flix
Sun Dec 27, 2009 9:21 am
Forum: General Bullet Physics Support and Feedback
Topic: skeleton or vertex animation using bullet
Replies: 2
Views: 2154

Re: skeleton or vertex animation using bullet

1) calculate the new vertex position. 2) create a new rigid body with the new vertex position data 3) add the rigid body to world 4) physics world step Well, this shouldn't be done in real-time simulations. I've never needed to do animations myself, but I suggest just using a capsule controller aro...
by Flix
Thu Dec 24, 2009 12:58 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Breakable convex decomposition demo (with source code)
Replies: 2
Views: 8154

Re: Breakable convex decomposition demo (with source code)

This is just an ugly image of the demo I posted:
ConvexDecompositionEx.JPG
ConvexDecompositionEx.JPG (22.91 KiB) Viewed 8153 times
Happy Xmas to everybody!
by Flix
Thu Dec 24, 2009 12:54 pm
Forum: Applications, Games, Demos or Movies using Bullet
Topic: Breakable convex decomposition demo (with source code)
Replies: 2
Views: 8154

Breakable convex decomposition demo (with source code)

WHAT'S THIS? This is just an extension to the Bullet Convex Decomposition Demo I made several months ago (probably half 2009), to add VERY BASIC support for breakable compound shapes. Hope newbies will find it useful. INSTALLATION The attached compressed archive contains one redundant file (ConvexD...
by Flix
Thu Dec 03, 2009 11:48 am
Forum: General Bullet Physics Support and Feedback
Topic: btAtan2Fast too approximate
Replies: 2
Views: 1420

Re: btAtan2Fast too approximate

rponomarev wrote: I replaced it by btAtan2() as of r1833 AFAIK there are still some btAtan2Fast calls in btConeTwistContraint.cpp. (Or maybe you can temporary replace it in btScalar.h and make it call btAtan2 to avoid these problems, in case somebody will find a better implementation in the future)...