Search found 13 matches

by LvR
Wed Sep 01, 2010 8:39 am
Forum: General Bullet Physics Support and Feedback
Topic: bullet-2.76 for MinGW
Replies: 4
Views: 1390

Re: bullet-2.76 for MinGW

Hi, I've just download the bullet-2.77-beta.zip, and it compiles and runs well with the following : - Code::Blocks 10.05 MinGW package (with glutmingw added from here : http://chortle.ccsu.edu/Bloodshed/glutming.zip) - CMake 2.8.2 - Compilation done like this : @echo off rem Specify the path to your...
by LvR
Fri Jul 18, 2008 5:56 am
Forum: General Bullet Physics Support and Feedback
Topic: Java port of Bullet
Replies: 122
Views: 178454

Re: Java port of Bullet

Hey, that's a great news, thx
by LvR
Wed Mar 26, 2008 7:21 am
Forum: General Bullet Physics Support and Feedback
Topic: HingeConstraint constructor bug
Replies: 16
Views: 5239

Re: HingeConstraint constructor bug

OK, I've set up a visual studio environnement and have a repoduction case. Just put this in BasicDemo : void BasicDemo::initPhysics() { setCameraDistance(btScalar(8.)); m_collisionConfiguration = new btDefaultCollisionConfiguration(); m_dispatcher = new btCollisionDispatcher(m_collisionConfiguration...
by LvR
Wed Mar 26, 2008 7:18 am
Forum: General Bullet Physics Support and Feedback
Topic: Quaternion inverse() in btQuaternion.h
Replies: 3
Views: 2605

Re: Quaternion inverse() in btQuaternion.h

I've found this when checking a HingeConstraint constructor bug, where I had a inverted axis after using quatRotate(...), so I think it should be corrected because I got a inversed Vector here : SIMD_FORCE_INLINE btVector3 quatRotate(const btQuaternion& rotation, const btVector3& v) { btQuaternion q...
by LvR
Tue Mar 25, 2008 12:46 pm
Forum: General Bullet Physics Support and Feedback
Topic: Quaternion inverse() in btQuaternion.h
Replies: 3
Views: 2605

Quaternion inverse() in btQuaternion.h

Hi, I' ve a small question about inverse() as coded in btQuaternion.h : btQuaternion inverse() const { return btQuaternion(m_x, m_y, m_z, -m_unusedW); } I thougth that inverse was the conjugate divided by the norm (if not a unit quaternion) So I would see instead : btQuaternion inverse() const { ret...
by LvR
Thu Mar 20, 2008 3:41 pm
Forum: General Bullet Physics Support and Feedback
Topic: HingeConstraint constructor bug
Replies: 16
Views: 5239

Re: HingeConstraint constructor bug

Yes, so in a right-handed system, i think that is correct ?

Code: Select all

a2 = a x A.x ( Y = Z x X )
the good question is : what system bullet use internally : left or right handed ?
by LvR
Thu Mar 20, 2008 9:13 am
Forum: General Bullet Physics Support and Feedback
Topic: HingeConstraint constructor bug
Replies: 16
Views: 5239

Re: HingeConstraint constructor bug

The cross product is ... a cross product, I think there is only one way to compute it. But, assuming a is the wanted Z, a2 the wanted Y, and that Bullet is right handed (I've check that in demos from bullet 2.77 in visual studio express 2008), the right cross-product should be : a2 = a x A.x ( Y = Z...
by LvR
Wed Mar 19, 2008 8:54 am
Forum: General Bullet Physics Support and Feedback
Topic: HingeConstraint constructor bug
Replies: 16
Views: 5239

Re: HingeConstraint constructor bug

I must set up a c++ dev environnement to test, because in my java env I must inverse your cross-product and Z axes

Here is the code that works for me :

Code: Select all

p = a ° A.x
if p ~ 1:
   a1 = -A.z
   a2 = A.y
elif p ~ -1:
   a1 = A.z
   a2 = A.y
else:
   a2 = a x A.x
   a1 = a2 x a
by LvR
Wed Mar 19, 2008 7:15 am
Forum: General Bullet Physics Support and Feedback
Topic: HingeConstraint constructor bug
Replies: 16
Views: 5239

Re: HingeConstraint constructor bug

Thx DragonLord. I've first use a double cross product formula then reduce it to a dot product .... it's seems it's not a good optimisation You are right to directly take A.* for new axes if p ~ +/-1 for the reverted X, I 'm completely confused, maybe it's a bug in my demo or in JBullet. Can you expl...
by LvR
Tue Mar 18, 2008 11:53 am
Forum: General Bullet Physics Support and Feedback
Topic: Java port of Bullet
Replies: 122
Views: 178454

Re: Java port of Bullet

but it doesn't work with http proxy .... I'll try with a ssh tunnel via my home box
by LvR
Tue Mar 18, 2008 11:06 am
Forum: General Bullet Physics Support and Feedback
Topic: Java port of Bullet
Replies: 122
Views: 178454

Re: Java port of Bullet

I think it would be great to use this package name, and if Erwin is ok, I also suggest you use the Bullet's SVN repository for the java port ?
by LvR
Tue Mar 18, 2008 7:32 am
Forum: General Bullet Physics Support and Feedback
Topic: HingeConstraint constructor bug
Replies: 16
Views: 5239

Re: HingeConstraint constructor bug

Thx for your answer, I should have check bug reports first ;), it would have save me time (but I haven't done maths for a while, so it's good to pratice again) Maybe you should add some comments to the constructor if it's a known issue or if usage is limited with no limits. And what do you think abo...
by LvR
Mon Mar 17, 2008 10:19 am
Forum: General Bullet Physics Support and Feedback
Topic: HingeConstraint constructor bug
Replies: 16
Views: 5239

HingeConstraint constructor bug

Hi, I was toying with JBullet and had problems with HingeConstaint. I first though it was a java port problem, but I checked in Bullet cpp source either : When I use the constructor with pivot points and axis, the joint is correctly placed between two bodies but limits doesn't work (it works well wi...