friction broken on OS X (bullet 2.82) ?

[gaspard]

Hi there,

Friction seems to be broken on OS X. I downloaded bullet 2.82, ran cmake and then make (got lots of warnings).

Now when running AppAllBulletDemos, the bed in front of the fork lift just slides to -Z.

This happens to all demos: object behave as if there was no friction. It does not look like this video or what I had experimented with previously.

(it also happens with my own code using a cube falling on a plane).

Any help greatly appreciated

Gaspard

[Erwin Coumans]

This is likely due to a clang bug. A workaround is applied in a recent trunk version at github, please try and report if this fixes the issue for you:
https://github.com/bulletphysics/bullet3

I'll make a new Bullet 2.83 release soon, based on this github source repo (which includes Bullet 2)

[gaspard]

Many thanks for your reply

I tried building the latest version from github but got some errors:

Code: Select all

==== Building OpenGL_Window (release32) ====
GLInstancingRenderer.cpp
../../btgui/OpenGLWindow/GLInstancingRenderer.cpp:1725:3: error: use of undeclared identifier 'glVertexAttribDivisor'; did you mean 'glVertexAttrib4iv'?
                glVertexAttribDivisor(0, 0);

[Erwin Coumans]

Which operating system, compiler and build system did you use (please provide full version for all 3).

[gaspard]

System: mac OS 10.8.5

Compiler:

Code: Select all

$ g++ --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 5.1 (clang-503.0.38) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin12.5.0
Thread model: posix

Build system:

Code: Select all

cd build3
./premake4_osx gmake
cd gmake
make

[Erwin Coumans]

It looks like Apple doesn't support OpenGL 3.3 or above on OSX 10.8.5, so it won't work.

I'll have to figure out a check for the OpenGL version in the build system (or at compile/run-time)

[gaspard]

OK, many thanks for your help.

To summarize:

• 2.82 does not build correctly on OS X 10.8.5 because of some compiler bug
• latest code from github does not build on 10.8.5 because of missing OpenGL 3.3 support

I'll think the night over to decide if I upgrade my OS to 10.9 (I have a show in two weeks and need the physics simulation).

[Erwin Coumans]

Latest version of https://github.com/bulletphysics/bullet3 should work on your older Mac OSX 10.8.x system now,
it will skip the OpenGL 3+ demos, but the OpenGL 2.x demos should work, either using premake or cmake.

cd build3
./premake_osx gmake
or
./premake_osx --bullet2demos gmake
cd gmake
make

Can you give it a try?
Thanks!
Erwin