Wednesday, 6 July 2011

Developer Journal 110

I made an arm bend!

The simulation has been crashing lately after saving and loading occurs a few times. I suspect that I have some major memory leakage going on. I came in today and was greeted by the following error message.

Program received signal SIGSEGV, Segmentation fault.
0x6fcb2ebc in libstdc++-6!_ZSt14__convert_to_vIfEvPKcRT_RSt12_Ios_IostateRKPi () from D:\agi\tools\mingw32\bin\libstdc++-6.dll

I foolishly did a back trace and was greeted by an 8000 deep stack trace. I tried copying pasting it here but Blogger would not accept it. I look forward to fixing up this problem.

I was trying to learn more about how the hinge constraints work when I come across this illuminating gem in the Bullet Physics documentation.

hinge constraint between two rigid bodies each with a pivot point that describes the axis location in local space axis defines the orientation of the hinge axis

I wish I understood the constructor better.

btHingeConstraint (btRigidBody &rbA, btRigidBody &rbB, const btTransform &rbAFrame, const btTransform &rbBFrame, bool useReferenceFrameA=false)

I wish I knew more maths and physics. Still, I don't have to know more maths and physics to use btHingeConstraint::enableAngularMotor().



  1. Hi Binh,

    I'm happy that you did start working on those humanoid shapes !

    If that can help you, this is a centralized past from code across our project that used the 6dofgenericconstraint for joint and muscles.

    We just launched a website about our project, you can take a look at

    Looking forward on your project !

    And don't hesitate to contact me if you have any questions or problems with constraints and bullet.
    cyprien (@) huissoud (dot) ch

  2. Hi Cyprien!

    I'm glad to begin working on humanoid shapes as well.

    Thanks for sharing your code with me, I'm studying it at the moment. Physics code baffles me so it will be a long time before I can even form questions to ask.

    I had a look at your website and it looks fantastic. I look forward to seeing your project grow over time.

    P.S. Your humanoid bodies are awesome!